Duna Mastery Challenge - companion report.

[BechMeister]

Bechmeister's
-= DUNA MASTERY CHALLENGE =-
Companion Mission Report

 

<<<<<<<<<<FOREWORD>>>>>>>>>>

 

A while ago now I was recemented to do OJTs Duna Mastery Challenge:

 

There was only one issue though - I felt my very detailed approach to writing mission reports were not fitting for the challenge post format. 

To me it felt like the challenge format had to be concise and to the point, and not including the failed attempts... design consideration etc. - So I decided I would make a companion mission report to the successes and failures of each challenge. Writing in excruciating detail  - like I guess I have been come to be known for.

I hope that It is not considered in poor taste - I dont want to take the spotlight from the challenge.

I was super impressed by the scope of the challenge - all the steps from building a communication net etc. before sending the first kerbal (even if its theoretically not needed - especially not at the time the challenge were issued, were antennas were only really for visuals)

It all fit right with my own tendency to try add some "roleplayed" realism into the game. I thought it was a great way to go about it with Duna, and decided I would give it a go... (And I hope OJT expand upon the challenge in the future.)

I completed the first step back in February - because by chance a Duna was positioned for a fly by and an window to send a probe to Duna was there.. and I was a bit bored with finishing up K.G.01 and 02 at the time...  and after that I decided to visit Minmus before continuing with Duna (it seemed like a better way to spend the time waiting for Duna to be in position again).
 

Anyway I will be doing the challenges in order - maybe combining steps some times, (if its not considered cheating ). Feel free to join me in my success and failures, with your successes and failures here on this space.. or questions, remarks advice etc. 

<<<<<<<<<MISSION_TASKS>>>>>>>>>

On 2/28/2023 at 9:15 PM, OJT said:

1. Destination Duna

Pretty straightforward: build an Unmanned Probe and perform a fly-by of Duna. Very broad definition of "Probe" here: you don't need to have antennas or means to generate electricity. As long as it has a Probe Core and it fly-bys Duna - you're in

subsidiary goals:

A. develop a reusable satelite carrier. + a satelite with enough Δv to get to Duna. - Success

B. Launch satelite and return 1st and 2nd stage. - Success

C. Perform fly-by of Duna. - Success

 

<<<<<<<<<<< Lessons learned; Lessons Identified>>>>>>>>>>

Goal Post A:

Left - Multifuel glider (Methalox). Right - Prototype of Satelite Deployment Glider (SDG)

The fact that the first mission task were so "easy" - I mean - flying by Duna within its sphere of influence should be a pretty easy task? Just make a vehicle with enough Δv and then some, to make room for rookie mistakes too - So I felt like I had to make it a little more interesting by launching it with a launch vehicle that were reusable.

The easiest thing to do was to take my Multi Fuel Glider from the service vehicles for my Space Gates (K.G.01 and K.G.02.) and tweek it to my needs. Of course it would limit me in how big a satelite I could make - but that would give a fun constraint to design around.

The Satelite Deployment Glider (SDG):

The Multi Fuel Glider is normally carrying a payload of 4t methalox - which meant that as long as the probe only weighted 4t - the flight characteristics should be the same. The most important design goal was keep the center of Mass and Center of Drag at the same place - If not, the body flaps (the 2 AERO BREAKS bellow the rear engines), had more range of motion to balance slight changes. You see - previous versions of the glider had issues were going through the atmosphere with the rear frist - not ideal..

I ended up countering that with 2 aerobreaks I could deploy with a hotkey. When the vehicle was re-entering I watched the SAS - as soon as I could see it the indicators that it used "force" to keep its angle of attack (around 40°), I adjusted the deployment angle of the breaks. The glider became stable at 25% deployed.. So there would be plenty of angle to play with.

The two gliders side by side.

Because I hated the look of the cargo bay doors going through the tail wings - The space available for a cargo bay would be quite limited. To keep the weight as far away from the rear as possible (the reason I have a light tube between the engine plate and the wing section on the original glider) - I decided to place the cargo door between the RCW and the rear fuel bay. (just remember to connect the fuel tanks to the "engine plate" with fuel lines, if you use a tube to separate the the space like i've done.

With the glider made it was time to make a simple probe that would fit within the cargo bay.

 If you want all the details in developing the Multi Fuel Glider - See the block post in the spoiler section:

Spoiler

The Probe:

The limiting size of the cargo bay (being a size medium and rather short) - made for a fun design challenge. To keep the probe within the limits. I knew the probe was going to be small - so a small 48-7S "Spark" would be plenty of power for the smalle probe - and the small size of the engine was also ideal.

I tried to fit a OSCM-01 "Mini Lab" and make a voyager esque probe - but it was hard to give it enough power to be able to collect science and not have balloon in size. In the end I looked at the requirement for the challenge completion - and since it could essentially be a projectile.. I thought it would be overachieving enough just to put a dish on that could reach KSC. So it became the simplest of probe. a core, some solar panels and enough methalox to get to Duna.

Speaking of which - If you're new to the game and you dont know this interactive Δv map, I highly recommend it  It looks like this:

That together with this graph for the optimal transfer position:

 

- makes it a lot easier to plan the vehicles. in the end the probe got look like this:

The craft may be small but it still packs a wooping 1.986 Δv - which should be more than enough, considering it should only take 950 Δv to escape Kerbin SOI + the 130Δv to woosh by Duna. (If I am reading the Δv map correct) - I mean the probe will be doing its transfer burn from LKO. ~80km 

Goal Post B:

The satelite deployment glider burning into a LKO while the 1st stage is burning back to KSC.

As mentioned in Goal Post A - the Multifuel glider that this vehicle is based on is well understod from its use servising K.G.01 (Kerbal Gate 01 - a space fuel station in LKO). The satelite carrier with payload is not slightly lighter than the multifuel glider. So getting to space did not pose any deviation from the flight procedure:

1.  Launch the vehicle.
2. as soon as it is clear of the tower, tilt ~5° eastward and lock prograde
3. allow vehicle to gravity turn on its own - unless you can see you will hit the 45°E mark before hitting the upper atmosphere (band 3) - then hold and before allowing it to gravity turn once appropriate. 
4. Once at 1600 Δv - engine cut.
5. stage separation.
6. orbit the SDG.
7. De-orbit the 1st stage.
8. make sure the 1st stage does not exceed 700 m/s on the way down (the engine plate will not tolerate the heat from higher speeds)
9. Land the stage at KSC. 

All these steps went without incident.

1st stage returning back to KSC.

One thing that is odd though is that even though I copied the vehicle from the K.G.01 service vehicle package - 2/3 nozzle extenders break off on separation on this version, were it does not on the Multi Fuel Glider version.

After the stage had returned it was a simple matter of getting the glider into space - it is very low powered. But it just means you have great control when circularizing the orbit. Here at 80km to comply with the Δv map.

SDG deploying the communication satelite.

After the satelite had been deployed it was just a matter of deorbiting the glider and landing it back at KSC.

The glider is pretty well balanced at this point. My best advice for making space plane on re-entry is that if your ass is flipping up front - or you can't hold your desired angle of attack at on your way down (mine is 40°) - you can add aerobreaks to the tail of the glider - these will function as body flaps and help it hold its orientation. read Goal Post A for more details 

I wished we had dedicated body flaps - it looks alright with the aerobreaks, but an actual body flap would have looked better.

SDG during re-entry - notice the body flaps helping it "keep its nose down".

Another pro tip is to mark the runway with some sort of small rover - it gives good aiming markers and makes it easier to see if your prograde is on target - especially considering that the prograde most likely is a few degrees bellow the direction your flying:An example of the glider aiming towards the runway - the prograde is positioned on the target to make sure I have enough energy for the flare maneuver. 

Half a day later the  glider was back at KSC ready for a refurbish and the next mission.

For detailed slideshow of the mission, see spoiler section bellow:
 

Spoiler

The SDG ready for take off around midday.

The seven S4 KS-25 "Vector" blasting the vehicle into space. Notice that the 4 grid fins are deployed - this is the only thing that keeps this, otherwise unstable "rocket", from flipping.

engine cut.

Stage separation and flip maneuver of the 1st stage. - it annoys me that the spacers break off.

lining up the launch pads on KSC - the 2 control surfaces at the end of the body allows the rocket th glider rather well all things considered. It's a very forgiving rocket to get back to the pad.

3/7 S4 KS-25 "Vector" engines are carefully managing the speed down to the pad.

slowing down.

and landed - now back to the SDG

The satelite is successfully deployed in LKO.

The SDG perform a partial de-orbit burn, just to be sure that it won't be interfering with the satelite while time warping to the correct deorbit position.

Over the desert the final deorbit burn is performed. exhausting the last methalox and aiming at the runway on KSC.

engine cut and coasting phase. - the cold blue and glowing engines.. I never get tired of looking at that.

Cutting trails of plasma through the atmosphere as the sun sets. AoA at 40° and stable.

once through the thick part - the body flap is retracted and the glider aims for the runway.

touch down in the dark.

safely down, parked outside the VAB.

Goal Post C:

Probe arriving at Duna.

It was time for the probe to perform its capture burn to its destination; Dune - Desert Planet...

As seen in my entry in the Duna Mastery Challenge - I did not have an optimal transfer window to Duna. But as you can also see, it didn't matter - the probe had ample of fuel to get it done:

Image of the maneuver node that would bring the probe to Duna.

If I can offer an advice - The game does not display the position markers for the vehicle and target when there is a Sphere of Influence between you and the body you want to intercept..

Let me explain: here we are moving from Kerbin SOI to Kerbol SOI and then Duna SOI - So the markers will only show once you leave the Kerbin SOI.

do the maneuver burn as well as you can from the maneuver node (lets just agree that the maneuver node system in game is not really geared for high precision, I used it more as a guide line.) Once you leave the Kerbin SOI you will get the markers, and then you can fine tune the path until you pass through the Duna SOI. (because you are so early in the process, a lot of the time you can do the corrections with the RCS thrusters - this craft had none.. so it would be with main engine)

From here on it was just coasting pass Duna and wave it goodbye - first challenge succeeded.

The probe performing fly by of Duna.
 

<<<<<<<<<<Moving Forward>>>>>>>>>>>

Challenge one has been complete.

I think I will challenge myself for the future by limiting myself to designing vehicles that fit within the space of the glider for as long as possible.

After my Minmus mission, I am in the mood for something smaller and less elaborate.

Stay tuned for more!

Edited August 24, 2024 by BechMeister
Put the mission as active again.

[BechMeister]

-=R&D_UPDATE=-
CommNet - Satelites and the Molniya Orbit

I figured a good way to continue with this blog - would be to alternate between a R&D post and a Mission Execution Post. Where all the theorycrafting on "how to solve the challenge", will be poured into a post first, and then I follow that up with a Mission Execution Post. I have a feeling that a lot of good discussion can come from making a theory and testing if it worked... at least it will give people a chance to say how wrong I am in my calculations and theories - and stop me before I do something really silly  Or better yet.. give people something amusing to read.

Any way - Without further ado - here is next challenges

On 2/28/2023 at 9:15 PM, OJT said:

2. Otherworldly Connection

Build an Unmanned Satellite and enter Duna orbit. Satellite must have an antenna strong enough to reach Kerbin and have means to generate power. Take Ike's SOI into consideration when you plan the orbit!

3. Transmitting Live From Duna

Set up a Relay Satellite constellation in Duna's orbit. There must be at least 3 satellites in the constellation. Each Satellite must have a Relay antenna strong enough to reach Kerbin and have means to generate power. You can either launch new satellites or add some to the one you've sent in Challenge 2, as long as the Satellite from Challenge 2 satisfies the aforementioned requirements

Before we talk about the 2^nd challenge I am going to ignore it for a little while, and focus on the 3^rd challenge first = 3 CommNet Satelites in Orbit around Duna - To me that screams for a Molniya or Tundra orbit. - Something I've been wanting to try out for a while now.

If you dont know what a Molniya or Tundra orbit is - See spoiler section bellow:

 

Spoiler

The Molniya Orbit:

Example of a Molniya Orbit with 4 satelites.

The Molniya and, its cousin, the Tundra orbit are both very elliptical orbits. with orbits that, respectivly, have a period of ½ and a whole sidereal day and at a very specific inclination to the body they orbit (63.4° around Earth)  . The Inclination needs to be this specific  in order to cancel out the "pull" from the equatorial bulge - that otherwise slowly alters the orbit. (the "Fat Earth Theory"). 

Inclination:

You see, the fact that earth bulge at the equator means that it will pull a satelites inclination down towards the equator over time. But at 63,4° - the effect is canceled out. In KSP this is not an issue since all bodies are perfect spheres.. So we can orbit perfectly at any inclination.

Orbital Period:

The other interesting thing about the Tundra and Molniya orbit is the period with which they orbit -namely a Half and A complete Sidereal day. 

A Sidereal day uses the stars in the background as its point of reference, where a Solar Day uses the stars as reference. So roughly speaking - A sidereal day is how long it takes the body to rotate so that distant stars appear in the same location from the night before. 

Why this orbit:

The point of the Molniya and Tundra orbit is to give coverage to the polar regions, that do not have line of sight to geostationary communication satelites. The Polar Region will always be able to see at least 1 satelite in a Molniya or Tundra Orbit.

A vehicle in a Tundra orbit will orbit over the same spot once every revolution, and the Molniya every second revolution.

There are 2 reasons why I am thinking about a Molniya Orbit:

1. A Geostationary orbit will not have Line of Sight to the poles of the planet - and It would make sense for future settlements to be near the poles were there is water ice. So a Tundra and Molniya orbit is necessary for such an settlement to be able to communicate with KSC. (Roleplaying)
2. Since the orbit is highly elliptical, it will be more likely that none of the satelites are hidden behind Duna - which should be able to have reliable coms with KSC with fewer satelites and that there are no signal loss to KSC. (except when Kerbol is in the way)

Now how do I propose to make a Molniya constellation around Duna you ask? My plan is this:

 

1.  Get 3 long range satelites to Duna and space them 120­° from each other around the planet, 0° inclination. 
2.  Get them to burn to a 60° inclination to Duna while maintaining ~120° separation. (hopefully the burn will be quick.)
3. Have them raise their Apoapsis to 6700km. (half a sidereal day - see vehicle design section to see how the AP is calculated)

Now to complete this task - the Molniya satelites needs a carrier with an antenna strong enough to get signal from Kerbin. If you guessed that this will be the satelite from challenge 2 you are correct.

My crazy idea is to make a Satelite Carrier - deploy it to Duna and put it in an orbit where I can space out the 3 Molniya Satelites in a 100km orbit -  Then perform the 3 steps to deploy them at their correct molniya orbit (Pe: 100km Ap: 6700km) . After this the satelite carrier will deploy the 6 small cube satelites evenly on the 100km orbit - which will provide signal around the equator. Once that is done - we will see how much Δv it has left on the Satelite Carrier and find a good plan for that. 

If this sounds like it's going to be difficult... I agree... This will be a test of my patience and precision.

Resonant Orbit Planning:

Now I thought I would have to sit and actually use my brain to calculate the correct orbit periods etc for launching the satelites to get their space even across the orbit - however I was gifted this great tool that does it for you. Use this to plan the spacing of satelites. 

When I plot in 6 satelites orbiting at 100km I get these ranges: 

The smart thing about planning around 6 satelites LOS is that it resonates with the 3 Molniya satelites - which will be deployed on every second orbit instead of every orbit.

If you - the reader - sees that I have made some terrible error.. please enlighten me 

Now the parameters of the mission has been planned. Now it is all about designing the vehicles.

<<<<<<<<<<Designing the Vehicles>>>>>>>>>>

The CommNet Satelites:

Left: Cube Satelite - Right: Molniya Satelite.

Molniya Satelite: 1064 Δv

Cube Satelite: unknown (25kg of Monopropellant and 2 RCS thrusters. - more than enough Δv)

Now for the communication satelites the Molniya Satelites are the ones that will be most demanding. They will have to burn from a 0° inclination to a 60° inclination - then raise its apoapsis to match ½ a sidereal day... Now.. How to calculate this number was lost on me. Even though I could find the equation online multiple places I could not get google to calculate it propper. So I asked for help on the forum, and help was received. Thanks to @K^2 and others for helping me wrap my head around this. 

To aid others (and myself in the future) I have decided to save the process here:

How to find the AP:

To find the AP for your desired Molniya Orbit you need to first find the Semi major axis of your orbital period - you do that with this equation:

Quote

a = (μ*T²/(2π))^1/3

 

a = Semi Major Axis.
μ= Standard Gravitational Parameter - See KSP Wiki 
T= ½ a Sidereal rotation Period - See KSP Wiki.

If you punch that into google so it looks like this:

Quote

(3.0136321E11m^3/s^2 * (32758.93s)^2 / (2 * pi))^(1/3)

Google is smart enough to understand the values Meter and Second and how they relate to each other.

You should get this number: 3,719.831km - which is the Semi Major Axis for a ½ a Duna Sidereal Rotation Period.

Now this number is the distance between Apoapsis and Periapsis - you may think "but that is an oddly big number" - at least that is what I was thinking. But that was because I "forgot" that there is a planet in between, and that the distance we are shown is taken from the "sea level" of the planet/body. We there for have to subtract the planets diameter. (or radius*2)

Now - I have decided that I want a PE of 100km above Dunas Surface - So to find the AP you have to use this formula:

Quote

 

AP = 2*a - 2*R - PE.

a = Semi-major axis
R = Radius
PE = Periapsis

2 * 3,719.831km - 2 * 320km - 100km

This should give you a distance of 6,699.662km - which I have rounded up to 6700 km  - With 1064 Δv I hope we have enough Δv to finish both maneuvers. (it seems like it should be enough?)

Quote

Note: should your AP be outside the Body's Sphere of Influence you can shorten the Semi-Major Axis by increasing the number of orbits by lowering the Fraction in the formula for the semi major axis:

(3.0136321E11m^3/s^2 * (32758.93s)^2 / (2 * pi))^(1/3) 

By lower the fraction, (Like 1/4, 1/5 etc.) you increase how many orbits the vehicle should take before it is going to be over the same point on the planet again.

This formula is "plug and play" so to speech - you can go to the wiki and lift the numbers, pick your PE and find the AP for any body you want. 

If you want to know more read here:

The Cube Satelite:

If we look at the Resonant Orbit Calculator numbers: See spoiler section bellow:

Spoiler

we can see it only requires 40.4 Δv to lower the AP to 100km - I therefore decided that it would be more cost effective to just give the small satelite 25kg of monopropellant and 2x RCS thrusters to decrease the AP.

This makes the satelite much lighter than if it had actual engines - and I can carry much less fuel - thus making the satelites much lighter.

The Satelite Carrier:

Satelite Carrier with 6 cube satelites and 3 molniya satelites.

Carrier: 2091Δv

The carrier will have 2091 Δv which should be ample since it's going to be launched from LKO: 80km and the Δv map shows it only requires 1690 - 1700 to transit to Duna Low Orbit.

See spoiler section below for reference:

Spoiler

Now - one does not need to look at this monstrosity of a satelite twice to see it wont fit in the small cargo bay for the SDG... So My "promise" to make everything fit within the small cargo bay only lasted until the next challenge... *Teehee*because - of course this was the only excuse I had for a glider re-redesign - It wouldn't be me without it.

The SDGv2:

Left: SDGv2 - Right - SDGv1.

When I first flew the SDG on Challenge 1 - there were 1 obvious thing that struck me. It does not need the docking array. The vehicle is not meant to dock with K.G.01, like the  Multi Fuel Gliders are. So I can do away with that and get more cargo space already - without changing the center of mass and drag a lot.. - how ever.. the satelite is still too long...

But I figured I could add a bit of Tube in the end where the vertical stabilizers are and sort of have the satelite twist itself out of the glider... That being said.. I can easily see things go "wrong" though here... namely:

A theoretical comparison of me getting the satelite out of the cargo bay.

Nothing has ever gone wrong from banging sensitive electronics out of the box... *cough cough* - Luckily Kerbal tech is sturdy tech... 

Here are the two cargo spaces clearly visible - The SDGv1 still loaded with the probe that was send for the Duna Fly By of Challenge 1.

and here a side by side comparison. Luckily the weight savings of ditching the docking port means that even though the Satelite Carrier is pretty heavy at 8.06t - double the payload of its cusin, the Multi Fuel Glider - it only increases weight by 2.22t. Something I am confident that the 1st stage will not have any issues getting into orbit.

Weight distribution across platforms:

Multi Fuel Glider:.............................................................25.34t

SDGv1:................................................................................22.28t

SDGv2:................................................................................27.56t

 

<<<<<<<<<<CONCLUSION>>>>>>>>>>

The plan has been made, Math has been calculated and vehicles designed accordingly. 

Stay tuned in to see if the plan survives first contact with reality.

See you in the next one.

 

 

Edited May 2, 2024 by BechMeister
corrected a uneven number of < in conclusion

[BechMeister]

-=MISSION EXECUTION=-
KSP2  and the Three Body Problem.

KSC on a beautiful morning - right before launch.

<<<<<<<<<< Foreword >>>>>>>>>>

It feels a bit weird to keep doing this with what's in the news atm. I feel like mission reports are not that important as of now.. especially not when the games future is in question.. I dont know what I feel and think right now. We will see what happens once the vail is being lifted. The thought of KSP2 having the plug pulled before reaching its full potential sadness me.. I had looked forward to the colony part, and resource gathering.. but most of all the multiplayer.

Any way.. here is the Mission Update that answers if the R&D was well funded.. or a waste of time. I can tell you all the vehicles worked flawless, albeit some tweaks in the future can be made. The title of the blog? - Three Body Problem..? heh lets just say its my terrible humor.. but true too.

More on that bellow:

<<<<<<<<<<MISSION_TASKS>>>>>>>>>>

 

A. Launch Probe into LKO and return SDG to KSC. - Success.

B. Transfer Probe to Duna. - Success.

C. Deploy Molniya Satelites - Success.

D. Deploy Cube Satelites - Success.

 

<<<<<<<<<<Lessons Learned; Lessons Learned>>>>>>>>>>

Goal Post A:

Drone Carrier with CommNetwork being deployed to LKO.

As I expected this step went without issues. One tiny thing was identified though as a possible improvement.Upon stage separation the 1st stage is pushing the SDG, making stage separation difficult. I have decided to experiment with replacing the tubes between the 1st stage and the SDG with the small gitter tubes - I am going to try hot staging to aid the separation. - We'll see next mission how it goes.

Because this step was going to be a walk in the park - I decided to use the step to practice my precise deployment. Although it expended more Δv than if I had just got it into the ballpark orbit, It still had plenty of Δv to get down again.

By adjusting the RSC thrusters down to 1% and the engines to 1% I managed to hit a perfect 90km circular orbit:

The SDG right after 90.000m AP has been achieved, notice that it burned 45° to the Prograde - Not very efficient. HUD cropped into top corner: The achieved 90.000m x 90.000m orbit.

One thing that the practice run(to achieve a precise orbit) showed, was the importance of having an engine with the appropriate power. if 1% thrust is not low enough for fine maneuvering - I would consider putting a weaker engine on.. or make sure the RCS is propper balanced - The glider has 3 thrusters for reverse and 2 for front - which actually was too much power even at 1 percent. Actually I would like to have sub 1% to work with.

The deployment of the probe was possible - even without using the time warp hack:

The SDG deploying the probe.

When I performed the stage separation I could wiggle it 45° degrees - It was kind of stuck from there.. but by using the RCS thrusters on 10% I was able to slowly fly it out - The decoupler, which was supposed to be staying inside the glider broke off though and was left as space trash. Also I never checked to see if the engine clipped through the back of the glider.. but hey.. the probe got out.

That being said I did encounter an annoying bug - When ever I timewarped with SAS set to Prograde/Retrograde - Radial in/out or Target. The probe would bend out of shape:

Quote

I will attach a bug report here once approved - With the current situation with Intercept Games, I assumed bug hunting effort is on hold until further notice? So I have not bothered reporting the bug yet- Normally I wait for my bug reports to be approved before posting the blog... but I wanted the update out now

Any way - the counter to the bug is to make sure you have locked your orientation, or are pointed towards something that does not move while in time warp (Like a maneuver node)

Before we move on to Goal Post B - Of course the SDG and 1st stage was safely returned back to KSC.

See spoiler section below for detailed walkthrough of the Mission Step:

Spoiler

The SDG blasting off the pad. It was a beautiful morning with light cloud cover. The volumetric clouds just looks awesome... SO.. I may have taken an excess amount of screenshots.

I really think the way the clouds simulate light is impressive.

right before engine cut.

Engine cut - flip and burn back maneuver.

flip and coasting before engine reignition. 

Controlled deacceleration. As mentioned previously - the engine plate will not survive speeds exceeding 700 m/s

aiming the rocket for the pad.

breaking the fall.

touchdown.

Back in space.

the glider pushing the AP to 90km

engine cut - the chrome just look so good.

Opening the cargo bay doors:

There it is in all its glory.

Probe deployed and the glider is ready for the back burn. 

Deorbiting the glider.

The glider did not have as much Δv for the deorbit maneuver as usual because I had been practicing the precise maneuvering. Fortunately the glide distance can easily be altered by banking left and right. - here the glider is starting to cut a blazing trail, still 50km up.

I never get tired of watching the gliders de-orbit.

Here adjusting the last range of the glide before continuing leveled flight at 40° AoA

bleeding of the final velocity - the blue and orange has always looked amazing together - notice that the bodyflap is not deployed at this moment.

the glider has entered the atmosphere - even though the glide distance had been shortened with the left right left banks - it still managed to extend the glide again while in "leveled flight"

It was nothing a steep spiral down couldn't remedy.

here the glider is "spiraling down" - in reality it's as close as a controlled dive you can get.

one of the last twist of the spirals before the glider is enough down to level the flight. - I am doing my best to conserve energy for the final flare.

lining up the runway and enjoying the look of the clouds and the chrome mirroring the blue sky.

coming through. still very high, its a good thing the runway is so long.

final flare up before touch down.

and now just coasting to the VAB.

and parked outside the VAB

Goal Post B: The Three Body Problem

Probe Carrier in LKO - getting the final telemetry from KSC before performing the 1st og 3 maneuvers that will bring it to a DLO

This step was almost breaking me and the Mission. I kept trying make plans that got me directly from a Low Kerbin Orbit to a Low Duna Orbit. But even if I did it with all the artistry in the world: Not just burning prograde, making sure Duna was in its ideal transfer window etc.(as well as you can when you need to use a protractor on the screen) I was plagued by issues.  

The vehicle kept not following the path the maneuver node said it would, It needed to have huge adjustments made once out of Kerbin SOI and I kept arriving at Duna with less than 100-200Δ after the break burn to get into orbit. Which was never enough to finish the mission.

After 2 tries I was about to throw the towel in ring when I remembered that getting vehicles back from The Mun to K.G.01 was never feasibly to go directly from The Mun. It was always more cost effective to burn out of The Mun SOI and then do the fine tuning in Kerbin SOI.

It seems to me that KSP2, as of now, can only really handle a maneuver made within the SOI your already in? - if you your maneuver crosses more than one.. you will have a very hard time getting the path right... And my maneuver was bridging three SOI.. or three bodies: Kerbin SOI, Kerbol SOI and Duna SOI.

Once I decided to split the entire transfer into 3:

1. Get the probe out of Kerbin SOI - while in front of Kerbin (so I dont have to burn through the SOI again) and with an AP leaning towards Duna.
2. Make a maneuver within Kerbol SOI that, as efficiently as possible, would intercept Duna at ~0 inclination (its hard to judge as you only get the numbers once in the bodies SOI) and with a PE of ~100km (the further you are from the object you want to intercept, the cheaper adjustments are.)
3. Once in Duna SOI, perform break burn and target 109.916km AP.

See spoiler section below for detailed walkthrough of maneuvers: but be warned, it's a bit of a mess

Spoiler

Direct Transfer from LKO to Duna.

First maneuver node with direct transfer to Duna.

Notice how much Δv the maneuver node said it would use - in the end the maneuver ended up taking a ~100 more Δv to complete, and there were a huge discrepancy between the path I ended with and the path the node said i would end with. 

In the end the transfer burn to Duna would spend 1313 Δv. And even though I would have less Δv on my 3 split maneuver - for some reason less Δv got me further. Even with 778 Δv - I could only just break to orbit Duna - and not even close to the desired orbits.

Maneuver from LKO to Duna split in 3:

First Maneuver to leave Kerbin SOI. - Notice I try to be more efficient with my burn by making sure I cross my Prograde ~½ way through the burn.

After end burn - notice the discrepancy between the maneuver node and the actual maneuver.

I made the second maneuver for the Duna Transfer by pulling on the prograde until the path crossed Duna's orbit - then I moved the node on my orbit until I had a good intercept. Notice how much further from the optimal transfer window I had to be to get a "cheap" maneuver.

I ended up with this path after end maneuver and 558 Δv -interestingly I had less Δv left compared to the single maneuver + correction. But there is a huge speed difference. The final adjustment was made with RCS thrusters.

Once inside Duna SOI i performed the last burn:

Notice that the screenshot was taken mid-burn.

I ended up around Duna with 157Δv to adjust the orbit to a perfect 100km PE - 190.916m AP

Looking at the screenshots now - I do not understand why I could perform the complete maneuver this way - when it seems I had 220 Δv more from the direct burn - but then I had trouble breaking and staying within Duna. I dont know if the velocity is the coulprit. In the 1 maneuver way, my exit speed ot Kerbin was 10245,3 m/s vs 9543,4 m/s = 701,9 m/s in difference.  Maybe in the end, it was just because doing it in 3 burns, meant I could be more precise with my PE arriving at Duna? Meaning I would need to do less maneuvers within Duna SOI?

Maybe someone with a lot of experience in KSP can tell me what I do wrong.. if not - I guess the further missions to Duna will tell me.

After 2 tries at a direct Transfer to Duna - I cut the transfer burn into 2 and finally arrived with enough Δv to continue the mission.

Drone Carrier leaving Kerbin.

Drone Carrier arriving at Duna.

correct resonant orbit achieved to deploy CommSat Network.

I arrived at Duna with  157Δv to adjust the orbit to a perfect 100km PE - 190.916m AP 

To see a detailed walkthrough of the mission step - see spoiler section bellow:

Spoiler

Carrier performing burn to leave Kerbin SOI

Drone Carrier performing second burn (outside of Kerbin SOI) to intercept Duna.

Breaking burn to orbit Duna.

here we see the probe burning at 1% to precisely tune the orbit for deploying the satelites.

Goal Post C:

First Molniya Drone burning away from the mothership to its 100km flat orbit.

Getting the molniya satelites into their orbits did not pose as a significant issue as I had feared going into the project, and all in all the theory worked in "real life". I have split this into a section surrounding each phase of the deployment. 

Phase 1: space the satelites 120° apart.

My biggest issue here was that the 48-7S "Spark" engines were too powerful for the task. Something that would not cause Issues in phase 1 and 2 - but later in phase 3 meant a lot of back and forth burning.

I ended up using Ike to find ~0° inclination to Duna - I really think KSP should have tools vanilla to give you the inclinations to the body you orbit. Any way - the drone carrier set to 1% engine power was really easy to control the orbit, and making sure the satelites were evenly spaced.

all 3 Molniya satelites deployed at ~120° apart. 100km flat orbit.

 

 See slideshow bellow:

Spoiler

1st Molniya satelite deployed.

Second molniya satelite breaking away from the carrier. - no pictures of the third.

Once the carrier had completed all deployments and arrived back at the Molniya Satelite 01 - this was the margin of error between them.

Phase 2: burn to a 60° inclination

Inclination burned.

I tried to get all 3 satelites to burn to their 60° inclination at the same time, by using pause etc. However the game would not allow it.

instead I had to burn one satelite at the time, meaning that they were probably not a perfect 120° degree separation between them. But it still look close enough to me. - the inclination burn shifted the orbit away from a perfect 100x100km orbit - but since all the satelites were pretty much still timed, I figured it would be easier to deal with in Phase 3.

Phased 3: Burn the satelites to their AP of 6700km

first satelite in its correct orbit.

I was quite nervous about this part - the whole point of the Molniya Orbit is that at least 1 satelite will be over the pole at All times, and moving slow enough that a simple antenna can track it. There were a few factors that would make it difficult, and a few unknowns that you can probably solve with math - but that I decided to just eyeball.

Getting into the correct orbit.

One of the factors that made it difficult was the in ability to mark the most southern part of the orbit. Which meant I had to eyeball when to burn prograde to raise the AP to the North. Fortunately the engines were easy enough to get the AP to 6700km - the problems arose once at AP. 

At AP I had to correct the wrong PE to a perfect 100km. The problem was that the engines even at 1% were too powerful - I kept flipping the satelite, burning prograde then retrograde trying to hit 100.000m flat. but instead jumping between 99.998 and 100.002m - In the end I got them all down to the correct orbit. 

A lessons learned lessons identified for the future is either to downgrade the engine power, or give the satelite a little bit of RCS (assuming the RCS at 1% is less powerful than the Spark engine - something that I've come to doubt)

Timing:

I was not sure how to time the satelites propper - and looking back with hindsight. I probably started out with something that would work better with a 4 ship orbit, rather than a 3.

How I solved the timing was by burning Molniya satelite 01 to its 6700km AP. while the Molniya Satelite 01 was at AP. I burned Molniya Satelite 02 to its AP. This meant I now had 2 satelites that would be at each their end of the orbit at all times. After that I figured that if i burned Molniya Satelite 03 to its 6700km AP while 01 was on its way down, and 02 on its way up - to cover the gab that would come between them.

In the future I think it is better to:

1. Burn Molniya Satelite 01 into its 6700km orbit. 
2. When that sat is on its way down (2/3) of the way in its orbit - burn the Molniya Satelite 02 to its AP
3. Once Molniya Satelite 02 is 2/3 done with its orbit. Burn Molniya Satelite 03.

I dont know if this will be a better approach. But looking at orbits speed up:

Molniya Orbit in action.

It looks like the timing is slightly off? all 3 satelites stays up together at one point in the orbit, and then just barely having 1 satelite over the poles another point of the orbit - I think with a 4th sat this orbital constilation would have been "perfect'er". (I guess 1/4th is always easier to guesstimate than 1/3)
 

Goal Post C:

The RCS thrusters on these cube satelites gave a lot of trouble - they were way to overpowered even with 1% thrust. I could not, for the love of god, get them to a 100x100km orbit. They kept dancing between 99.999m and 100.002m just flipping numbers. In the end I gave up getting them into a perfect 100x100 orbit and decided that they had enough monopropellant to correct orbits for a long while.

I tried to allow the satelite constellation to run for 3 more years without guidance, just to see the drift. Only 1 out of 6 cube satelites had drifted in its orbit.. and after docking and undocking K.G.01 a lot - I know exactly how to correct orbits for drifted satelites.

Asume a orbit either a few km higher or lower than the target orbit (slow down - speed up). once you're right above/below your target orbit.. rendezvous with your it by lowering your orbit again.

Example of almost hitting 100x100km flat - and having to give up.

After "successfully" deploying all 6 cube satelites in their orbit. I decided to burn the carrier into a ~200x200km orbit, to make sure it was out of the way. The satelite still have 264Δv left - I wonder if there is any better use I can make of it now. Either I include it somehow to the constellation - or I deorbit it.

Cube satelite constellation in action.

for slide show see spoiler section bellow:
 

Spoiler

first CubeSat being launched.

Second CubeSat being launched.

4th CubeSat being launched. 

Final CubeSat being launched - making the probe carrier seem awful disproportionate 

 

<<<<<<<<<< Moving Forward >>>>>>>>>>

Challenge 2 and 3 complete - and even with flying colours if you ask me.

I always wanted to establish a CommSat Network - now I finally got around to do it

before going on to Challenge 4 - Does anyone have any good ideas of how to use the Drone Carrier? It has 264 Δv left. So its very limited what kind of orbits it can achieve. But if any one have any suggestions on how to better utilize it, I am all ears.

Stay Tuned in for More! Next up - R&D for Challenge 4.

[BechMeister]

-=R&D_UPDATE=-
Tiny Lander

Good day! Here we are again, soldiering on while pretending everything is fine...

I guess it's all one can do at this point... I think I've come to the conclusion that if this was really the end of KSP2. I'll play the content that is there, and then take what I've learned and go my way into the ether.  Any way, todays post will be short.

After successfully establishing the CommNetwork around Duna. It is now time to go dig in the ground and figure out what the soil has to offer. The challenge is as follows: 

  

On 2/28/2023 at 9:15 PM, OJT said:

4. First Landing

Launch an Unmanned Lander (like Viking) and land it intact on Duna. Lander must have an antenna that can reach the Relay satellites, means to generate electricity and some sort of landing legs. Whether you choose to use already provided lander legs or make some of your own from structural parts is up to you

when I initially started to make builds for this challenge I thought it was going to be a walk in the park. But I was surprised how big even the small parts actually are. Also even though the the challenge does not ask for science parts - it just felt wrong to launch a lander that could not take samples from the ground. I mean, the Viking Probe mentioned as an inspiration has means to dig in the dirt:

Painting of the Viking Lander taking samples on the Martian Surface.

So science parts had to be there, now that they are here!

Designing a Lander:

Lander being tested on the Runway of KSC.

It is not easy to build this small. I knew my glider would only take vehicles that were - at maximum, somewhere between Small and Medium. medium would already be too big.. since the vehicle would not be able to leave the bay. So I had to build it out of the Extra Small parts:

Lander from the "front" and bellow.

The lander is basically constructed by taking a M-Beam 650, flanked by XS reaction wheels and strapping on 4 TMP-XS (the tiny 6 way connector) where I could add the 4 LV-1 "Ant's".  Giving the vehicle a total of 70 Δv. (the fuel tank is mostly left empty) The engines also doubles as landing legs.. Since even the smallest leg were huge on this thing.

The biggest issue were fitting the sample arm, (which is rather big actually) and not having it clip into the drogue chute. 

I added 2 solar panels and a z-400 battery - together with the tiny probe core it gives the vehicle EC of 405U. Lastly I added a ASCM-B "Little Sniffer" just because it looks like there is a camera on it.

Considering how much the cameras on the rovers give them personality.. I think its weird that we don't have a rover part with camera etc. on it. 

The lander totalled at .79t with fuel and .77t dry.

Now we just need to get it to Duna!

Duna Lander Transfer Stage:

From Bottom up: 1. Duna Transfer Stage 2. Duna reentry stage 3. lander.

So.. The lander is a little bit wider than the Small heat shield - I figured I could put in a faring that has a cone shape and put a small heatshield at the end. Hopefully the conical shape of the faring will mean that it takes less heat on the way down? and the heatshield will take the brunt of it.

The lander is connected via a decoupler on its side to it. Which is fitting any way since my plan is to get my PE just barely over the surface of the planet - to bleed of as much speed while flying horizontal - so I don't just Pancake into the ground (if the atmosphere is weaker than I expect). So it will be pointing in the correct orientation when deploying. 

The Transfer stage has 1967 Δv which should be enough to get a "impact" path to Duna - it is going to be quite interesting how much the atmosphere does? because even when sending missions to mars in real life we use heatshields right?

The Staging Plan is as follows:

1. Once the lander enters the atmosphere, stage separate the Transfer Stage from the Re-entry stage, and point the heatshield prograde. - The transfer stage will burn up.

2. Once the lander has bleed off enough speed to not rip the lander a part or melt it - drop the faring.

3. Engage the drogue shoot - to ensure the lander separates from the heatshield -  and stage separate the heatshield off.

4. gently touch down with the aid of engines.

The vehicle comes in at (with the lander attached to it) 4.30t total - meaning almost half as light as the CommNetwork Probe launched previously. So getting it into LKO should be a walk in the park.

Speaking of getting into LKO: 

Hot Staging:

To help the SDG separate from the 1st stage - I have tried to use 3x CT-S-1 instead of the 3x SF-125 as it looks closer to something that could enable hot staging - I don't know if the game will register it like that? or if the part will survive the heat - We'll see.. if they burn off I guess it does not matter much anyway. As long as the SDG flies clean off upon stage separation.

SDG with the Duna Lander vehicle attached in the cargo bay

<<<<<<<<<< Moving Forward >>>>>>>>>>

Next up is launch - Which I think I'll get done pretty quick. We'll see if the little thing does well - I guess with a lander like this, making sure you land on a flat surface is also alpha omega.

Any way - see you in the next update.

[BechMeister]

-=MISSION EXECUTION=-

The transfer stage bleeding off energy before deploying near the polar cap of Duna.

<<<<<<<<<<FOREWORD>>>>>>>>>>

I have decided that, even in the event that this is the end of KSP2(we dont know yet). I'll still continue to grind the content I can out of this game. I am at least aware of the most prolific bugs now, and know how to design around them... and I have only just left Kerbin.. There is so much more to get out of this sandbox still... The KSP2 engagement seem to be on the low end though.. and while I do enjoy making these long detailed blog posts about my progress. Not knowing if any one reads them, is killing my motivation to write them.

I will be finishing the Duna Mastery Challenge though! But I had planned to do the same rundown on Eve next.. But we'll see if that will be something I'll write about. I think that depends on what level the engagement with the game is like, at that point.

Any way.. This challenge went alright.. I must admit though that I was surprised with how thin Duna's atmosphere actually is (even though I knew it was). More on that bellow:

<<<<<<<<<<MISSION_TASKS>>>>>>>>>>

 

A. Launch probe into LKO and return 1st stage and SDG to KSC - Success

B. Perform Transfer Maneuver to Duna - Success

C. Land the Lander near the Polar Regions - Success.

 

<<<<<<<<<<Lessons Learned; Lessons Identified>>>>>>>>>>

Goal Post A:

The SDG launching the Probe into LKO.

This leg was pretty much business as usual - Although I did learn that the SF-125 will be burned up by the exhaust from the 3x Lv-909 "terrier's" - That did not bother me too much. It looks a lot better to see the exhaust plumes to "clip" through an part that is open, rather than clip through a closed cylinder.

where as it feel redundant to wish for something to be added to the game in these times... I still wish we could hot stage rings in the game.  

The launch went without incident and the probe was successfully deployed (being a lot shorter made it very easy, it flew out of the cargo bay on its own RCS power.

For detailed walkthrough of the launch See spoler section bellow:

Spoiler

Lift off! I kind of wish that the tower parts we use to hold the rockets.. were actual attachement points to the launch towers.

Blasting off into space.

Clean stage separation - 1/3 SF-125 burned away. - the other two would fall off.

burn back to KSC.

As you can see the two surviving SF-125 broke off on the way down - but I always liked the look of the 3 split piece without the extenders.

Lining up the pad.

And touch down - all routine now.

the glider is burning itself into an ~90.000m x 90.000m orbit. - I am not being precise this time.

close to the point of the reentry burn the cargo bay door slides open to reveal the probe to the vacuum of space.

Probe is deployed and the SDG is creating distance, as to not fry the satelite with its exhaust.

The probe is ready! Now it's time to land the glider. The fact that I did not try to be precise with hitting 90.000m x 90.000m, and that it was half the weight of the CommNet carrier, meant that the glider had ample of fuel for its deorbit burn.

The longer deorbit burn meant for a gentle reentry - the flames never got bigger than this.

I still managed to overshoot the runway, and had to do a hard break. before spiraling down:

by following the 45° angle from straight down, I made a really narrow spiral dive. Getting down quickly, while maintaining airspeed. It's kind of crazy that its terminal velocity is not much higher than 148,9 m/s

It lead us to come up perfect to the runway.

and touch down. 

 Goal Post B: 

Duna Lander Probe - making transfer burn to Duna.

Because I had the CommNet around Duna now, I decided to just put on a small antenna on the vehicle - with a range of 200 Mm. I figured the vehicle would only need trajectory when leaving Kerbin and approaching Duna... How ever I was surprised of how "short" 200Mm was in reality - not extending that far away from the Kerbin SOI. It meant I had to do a little quick load.. you see I had decided to do the approach of burning out of the Kerbin SOI, then make the maneuver for Duna at a optimal point. 

However - The optimal point was way outside CommNet range. So I decided to do a more expensive burn and then just make sure that the Duna PE would be a few KM above the surface. I would not have Δv enough to circularize around Duna.. but I didn't need to since I could just be Aerobraking.

the maneuver that got the Lander Probe to Duna.

The most important thing for me would be to bring the probe  over the North Pole - Final adjustment would be made once in the Duna SOI. - The probe was allowed to coast all the way to the Duna SOI without any signal - a bit harrowing... For a sec I thought that the CommNet wasn't able to relay signal.. but it was just because the signal was only reaquired after the timewarp stopped.

The probe had successfully arrived at Duna SOI

Goal Post C: 

Lander safely on the ground, taking its first sample.

 

Once inside the Duna SOI it showed that my my path would take me directly through Ike's SOI - which made aiming quite difficult actually - since Ike naturally gave me a high ark to Duna. 

The probe zipping past Ike on its way to Duna.

Fortunately there were plenty Δv left to push the PE down once I was through Ike's SOI. For RPG reasons I was interested in testing the soil near the poles of Duna - Seeing the canyons between the poles I figured that would be a cool landing site - so I aimed for this place:

After finding a point to aim at I, then raised the PE to 4km above surface - to make sure that the vehicle didn't pancake into the ground, if the atmosphere wouldn't break me as much as I hoped it would...

The last Δv was spend aiming the trajectory for the canyon - or general area.

The transfer stage being ditched - and the landing stage burning through the atmosphere.

once the atmosphere started to heat up, the transfer stage was dropped and the lander stage just flew through the atmosphere like a bullet. It bled of the energy.. albeit much slower than I anticipated - the lander would drift quite far before the speeds were dropped to a level were I felt comfortable the lander would not have been torn apart (at least in our world - In the world of Kerbals they have the alloy Kerbalium . And that is most sturdy) the fairing was dropped, and the scute deployed soon after.

lander drops fairing - creating a lot more drag.

After that it was just a question of dropping the heat shield - I dont know if its a bug? or if Duna's atmosphere is just so light it does not need heatshields...  At least it had not spend any of its ablative propperties . 

The scute was deployed and the 4 engines put it gentle down to the ground.

The lander breaking for a gentle touch down.

The lander would touch down a generally flat place, on the other side of the ice sheet I was aiming fore.. but at least in one piece. We are still taking a sample of the Duna Polar Soil, which can lay the foundation to find the ideal place for future manned Duna Missions.

The probes final resting place.

The battery power is a bit light - the lander goes all the way down to EC 70U before sunrise. If all unnecessary power usage has been eliminated. Of course the lander could go into hibernation mode in the night.. but I dont know if that is considered "cheating" in relation to the goal post stating that the vehicle should "have means to generate electricity" - I guess it has the means in the daylight.. but If we go by the Martian Landers and Rovers of our world.. power is spend in the cold nights, making sure mission critical hardware is not killed by the cold. I guess that is of OJT to judge.. where ever he is now days.

For picture slide show - see bellow:

Spoiler

The lander after having performed a Anti- Normal burn to adjust for planet rotation.

Saying goodbye to the transfer stage - here the lack off effect on the heatshield is clearly visible. 

the big canyon with the two white peaks in were the spot that I aimed for.

here flying over it - still in high speeds.

the last glow desapating. stage separation would happen just as the hot plasma would extinguish.

The protective faring separating from the craft.

Dropping the heat shield (no longer needed, and deploying the Drogue Chute - to ensure propper stage separation.

Drogue chute doing its thing.

As the sun sets the vehicle is closing in on the ground.

Touchdown!

The craft gets the last bit of sunlight be fore hanging in tight for the night.

The next day it was ready to do science.

<<<<<<<<<< MOVING FORWARD >>>>>>>>>>

with that being a - Challenge Success! - it is time to move forward.

Since the parameters of the next challenge is pretty much the same - at least if I just put wheels on the lander. I have decided to compile the R&D post for Challenge 5 and 6. Otherwise the R&D post for challenge 5 will be very short. Since I will mostly be able to use the same vehicles.

See you in the next one! 

Edited May 9, 2024 by BechMeister

[BechMeister]

-=R&D_UPDATE=-
Rovers and Mars Sample Return Mission:

So I just went through a lot of convoluted R&D to complete Challenge 6 - just to realize that I read the challenge wrong when I read it. I thought the requirement was to get a rover back and forth from Duna - Not a Lander.. (which does make the mission a lot simpler). I think that I, in my head, focused too much on perseverance as being part of NASA and ESAs real Mars Sample Return mission - without realizing that challenge 5 "is" the perseverance mission - that I build both challenges into 1.

Needless to say - Now I've build it - with 12 stages and all... to get it there and back again... So I'm going to do it! 

The challenges are as follows:  

On 2/28/2023 at 9:15 PM, OJT said:

5. Desolation Road

Design an Unmanned Rover, send it to Duna and demonstrate its functionality by covering some distance in it. Rover must have an antenna that can reach the Relay satellites, means to generate electricity and at least 3 wheels

6. Bring It Home

Design an Unmanned Lander that can land on Duna and then subsequently return it intact to Kerbin. If the Lander is multi-stage, the stage with Probe Core must be returned. Otherwise the requirements are the same as in Challenge 4

 

Challenge 5 Rover:

Updated Lander making a survey test near the Runway 1

Since the rover was going to be mobile. It made sense to replace the solar panels with a "Multi-Mission Radioisotope Thermoelectric Generator"(MMRTG) (NASA sure like their acronyms). In game it is known as the PB-NUK power plant.

Instead of a tiny drogue chute I gave it small MK16-r parachute - The drogue chute was almost enough to land the lander. So I hope that the small parachute will do and I can skip the engines... as I had trouble figuring out how to give it fuel and place rockets on it.

Challenge 6 rover and Sample Return Vehicle:

Since the challenge 6 required a vehicle that was big enough to get to Duna and back again, I knew it would not be able to launch it from the SDG. It gave an opportunity to develop a new and bigger rover. I wanted to cram as much science out of the vehicle as possible - and one of the most challenging things to get on it would be a WSRL-01 radiation survey. Which seems like a good thing to survey before a manned mission x) 

Now making the rover was not going to be the hard part... Making a vehicle that could deploy and retract a rover would be. The fact we dont have any crane parts meant that the rover had to somehow be able to drive in and out of the lander vehicle... or the vehicle would have to be able to lower a port that allowed it to dock to it again.

It took 2 attempts to develop such a vehicle:

Attempt 1:

a test of the vehicle on Runway 1 - notice the landing legs is placed to give stability and prevent the vehicle from falling on uneven surfaces.

The idea behind prototype 1 was that rover could drive in and out the bottom of the decent and accent stage. It would put a limit on the size of the rover - but the medium size would still be more than enough room for a rover with all the science equipment.

The Accent and decent stage looked like this broken up in its parts:

 

 

 

From bottom up:

1. Duna Decent Heat Shield - with deorbit engines.
2. Rover Carrier and Kerbin decent stage
3. Service Stage for Duna Kerbin transfer.

The landing procedure would be this: The Duna Sample Return Vehicle (DSRV) would decouple from the Kerbin-Duna Tour Retour Stage (KDTRS) and the tiny fuel load on the heat shield would deorbit the lander.  Once through the thick of the atmosphere the heat shield would be dropped to save weight. and the stage would land via engines and chutes.

Then the rover would drive out and do science, once ready it would redock with the lander and ascent again. Once into the vacuum the farrings would be blown off and the docking port would be ready to dock back with the KDTRS.

When back at Kerbin, the DSRV would then decouple from the KDTRS - again - and deorbit. Once de-accelerated (no more flames) it would also drop the heat shield and deploy a second pair of parachutes for a soft touch down..

However - theory and reality did not align. Once I had made sure the vehicle could land itself I was going to test if the Rover could drive back in. The fact that the engine plate is as tall as it is made me worry that it would not be able to drive over the step. I tried to replace the engine plate with other flat medium sized parts - but in the end it would be just as tall because of the engines.

Radially deploying the engines were not an option - since having the exhaust next to a surface drastically reduces thrust - and It was not possible to place them Infront of the doors (aesthetically it felt wrong to me.. if movable things clip through things it feel like cheating) 

My worry was well funded - but not only that I couldn't drive back in - For some reason the rover couldn't even drive off the engine plate.

Left: even if the engine plate did not have landing legs or engines the rover could not get in again.

Right: It's a bit hard to see  - but the wheels are just spinning.

Another way to make the vehicle had to be done. I remembered how I made my dropships for Minmus. And I decided to do something similar - see spoiler section for reference If you have not read my Overengineered Minmus Mission:

Spoiler

On 2/10/2024 at 8:59 PM, BechMeister said:

B. Designing a Dropship:

Attempt Two:

I decided to make a stage that would lie flat on the ground, and then by adjusting how much the cargo bay doors open, I could adjust the angle of the docking port - and by breaking and accelerating the rover. Or increasing spring strength on the front wheels and reduce on there rear wheels, I could make the rover pitch up and "catch" the docking port. I made a small mock up as a prof of concept: 

For a more thorough test of the landing of the proof of concept.See spoiler section:

Spoiler

Next was finding the way to get it back into space again. I developed a 2 stage system. A 1st stage with 1320Δv, just shy of being capable getting into DLO - and then add a little bit a fuel and 4x LV-1R "Spiders" to the "Proof of concept" 2nd stage giving it 357Δv. Which should be enough, and then some, to give it the last kick into orbit and rendezvousing with the KDTRS. 

Left Top: 2nd stage - Left Bellow: 1st stage - Right: the Duna Lander Module.

Next up was making a way to get it through the Duna Atmosphere. Now - since the Heat shield on challenge 4 did not take any damage - I decided to try do away with it on this build. Instead I build an aerodynamic faring and applied grid fins to help steer it down. The Duna reentry "vehicle" could then have a heat weak medium docking port as its "decoupler" - meaning that there is cohesion with the 2nd stage when it returns to the KDTRS.

The reentry vehicle is pretty simple. Its purpose is to just shield the vehicle from being scorched by the plasma, then blow off and allow the sample return vehicle to land.

It looks like this:

Launch Vehicle and KDTRS:

Last thing to do was to develop the vehicle that would bring this monster from LKO to Duna and back again. The easiest thing to do was to look at something I had build before and already flown a lot. I took the 1st stage for my Heavy Refuel Vehicle to K.G.01 (my space fuel station in LKO) as seen here:  

On 12/20/2023 at 9:43 AM, BechMeister said:

The final version, and fully certified H.T.V. - 2nd stage and 1st stage.

The 1st stage is designed to push. The Tanker Vehicle of 119.62t to ~900 m/s or 25-30km - before returning and landing at KSC again. So it has not trouble pushing the KDTRS + DSRV at only 79.08t into LKO if the stage is wasted.

Final design of 1st stage and KDTRS

The KDTRS has a total of ~3.439Δv after giving itself a tiny boost into LKO. That should theoretically be enough... When going to Duna I tend to use shy of ~2000Δv - the DSRV weighs  13.21t going to Duna - and less than 4.76t when it returns (depending on the fuel level upon docking). So I hope that 1.439 Δv will be ~2000 Δv. I could do the rocket equation.. But my gutfeel says it will be enough to go there and back again. 

If not I guess we will have a rescue mission to launch.

 

<<<<<<<<<< Moving Forward >>>>>>>>>>

I expect the launch Challenge 5 tomorrow - and then write the update Sunday? (we'll see how it goes - plans only last until contact with the enemy after all)

Stay Tuned - Until next post!

Edited May 10, 2024 by BechMeister
My son decided to be my editor.. and that I was a too slow writer and hit publish. Fortunately I am his father - So I overruled him and finished the rest in post.

[BechMeister]

-=MISSION EXECUTION=-
Murphy Strikes

The rover being launched into LKO.

<<<<<<<<<< FOREWORD >>>>>>>>>>

So! That was an odd launch - Everything went wrong - but not so wrong that the next leg of the mission couldn't proceed. Until the lander touched the Duna surface that is. I decided to just roll with it.. but in the end it became kind of comical how this update would only have a single suffesful task - namely getting the probe to Duna 

Any way, I learned something with every failure. - More on that bellow:

<<<<<<<<<< MISSION_TASKS >>>>>>>>>>

 

A. Deploy the probe with the SDG and return the SDG system to KSC. - Failure

B. Perform transfer burn of the Rover Probe to Duna - Success

C. Land rover on the surface of Duna - Failure.

 

<<<<<<<<<< Lessons Learned; Lessons Identified >>>>>>>>

Goal post A:

1st stage collapsed on the landing pad.

I dont know if i jinxed myself last mission post - by writing business as usual. Because even if I tried to get the landing to stick twice I failed twice. I decided to just roll with it... Even spaceX still tumbles a rocket every once and a while.

I am still not sure why I had such a hard time landing it - I had more Δv than I usually have. Maybe it made me more slobby? or maybe the weight of the rocket was the issue? In any case, on the 1st attempt I had lateral movement over the pad. Which meant that the rocket tumbled on the landing. I always try to come into the pad on an ark. I find that it is easier to kill lateral movement by coming on on an ark and slowly controlling the decent by burning retrograde until the lander is pointing straight up - with no lateral movement - and then controlling the de-acceleration for a soft touch down. I find if I, on the decent phase, fall "straight" down I end up getting lateral movement when doing the fine aiming for the pad.

On the second failure a leg broke off on touch down. I had a hard time timing the de-acceleration. I wonder if the extra weight of the excess Δv caused my timing to be off? Any way.. the result was the same. Maybe I should do some testing to see if having too much fuel coming down means the legs can't handle the weight.

Any way - back to the glider:

The SDG deploying the probe.

The glider made it to orbit and deployed the probe. The glider also had an excess of Δv. So I figured deorbiting would be easier than ever. I had overshot the runway the past too launches.. (still making it though) - So I did the decent burn earlier. But too much earlier. - The early burn plus excess Δv meant that It soon became evident that I would not make it to the runway by a longshot.

Finding a good landing spot was "alfa omega" - the glide efficiency is not great on the glider... you really need to time the flare maneuver right to bleed off speed and stick the landing. Too soon and you will pankage into the runway, too late and you will not be able to keep the nose pointing upwards, and the vehicle will break in two- and thats on a completely flat surface. Which meant that I could probably not land uphill.

I found a nice even looking patch of land and managed to land the vehicle on a small hill, devoid of trees (almost)

The glider touching down - notice the sharp angle the trails are taking - it was not a soft landing.

Lessons Learned: The glider can make an emergency landing if the landing site is carefully chosen.

For detailed walkthrough of the mission leg - see spoiler section:

Spoiler

the rocket blasting off.

Stage separation - I found that I burned my monopropellant tanks on hot staging - So I have moved them further down. Before they were situated right below the 3 split plate.

Returning to KSC.

aiming for the pad.

breaking through the thick clouds (made it hard to aim) - a Hud element you could toggle on/off that shows the pads and landing strip in the dark or heavy clouds would be nice.

a leg broke on the landing, and when it tumbled it rolled off all the grid fins and broke the top off.

back in space:

The glider finish its orbital insertion burn.

probe deployed.

performing deorbit burn over the southern cost of the western desert

controlling the decent. Since I was sure I was not going to overshoot this time - I just took a flat 40° AoA.

here from another angle.

Here the airspeed was dropping rapidly - and it was evident that I would never reach KSC.

I decided to break left as it looked rather flat.

I decided to go for this ridge as it looked relatively flat - and easier to land on than in the depressions on either side of it.

landing gear out. losing airspeed rapidly. 

Now it's just hoping that the landing gear holds.

And safely landed.. Now it just have to be picked up.. we're just a tiny bit off.

relativly speaking x)

Goal Post B:

The probe arriving at Duna.

I saw a smart trick on the internet - since the ideal transfer window to Duna is 44,4°. You can take a a piece of paper and fold it so it shows 45° and place that pointing on Kerbol and when Duna and Kerbin is visible from the paper - you have ~45° (which is close to 44,4°): see spoiler section for reference:

Spoiler

When I did this I was surprised how much off I had been - gauging the degree's with my mk.1 eyeball.  Because the image with ideal transfer windows - in degree's, had been simplified (all the orbits have the same distance to each other) - placing Duna in continuation of the position of Kerbin meant I was several degree's off. Its obvious I know.. 

Any way, getting a better transfer window meant that I came to Duna spending much less  Δv: Screenshot for reference

The probe arrived at Duna no problems.

Goal Post C:

the conclusion of this ill fated mission. A rover in pieces on the surface of Duna.

I had two problems coming in to this mission. First problem was that I was going too fast. If I just allowed the heatshield to be pointed forward the probe would just shoot straight through the atmosphere - Even if I spend all my remaining Δv breaking - the capsule would still accelerate to 2000+ m/s before being low enough for the atmosphere to do something. All I could do then was just wave Duna goodbye and have the probe be lost in space until Duna would line up again.. some time in the far far future.

Desperate times means desperate measures - I found that if I flew the probe backwards I would break: 

Duna Lander entering the atmosphere

Depending which way I pointed the probe I could even lower or raise the PE. giving some controllability..

The Second Problem was that the lander was too heavy and hit the ground with ~14 m/s and broke into pieces. 1 parachute was not going to cut it - it need breaking engines.

But two important lessons were made:

1.  Heat shield's are more of a hindrance on Duna - they turn the probe into a bullet and is just weight not spend. I got confirmation that the fairings can take the re-entry heat and will be building re-entry capsules for Duna with farings.
2. Duna's atmosphere is so thin that you cannot rely on parachutes only. Unless you put on a lot of chutes.

for detailed walkthrough of the landing - see spoiler section bellow:

Spoiler

spending the last Δv on breaking before releasing the transfer stage.

The burn lasted well into the atmosphere - the Δv was spend shortly before the engine burned off (lucky) - I then decoupled and as the capsule push away the lighter transfer stage. - now accelerating again.

Here from another angle.

I notice that the capsule is just building speed.

the capsule has flipped to break.

the farings are dropped.

Parachute deployed.

we are breaking.

but not enough

 

<<<<<<<<<< Moving Forward >>>>>>>>>>

Now - this blunder offers an opportunity to give Challenge 5 and 6 a new go. I have looked into the Mars Sample Return mission - that may be launched... And I actually really think its some nifty small vehicles ESA and NASA has planned for it. So I may design an actual lander that can work with a rover - and make a return vehicle with ION engines? They seem a bit gimmicky to me in KSP2 - I guess they are gimmicky in real life too... but their low thrust makes me think they take quite the patience to use. 

We'll see - Except a R&D post next - then I can launch all 3 rockets in the next duna transfer window.

Stay tuned in for more!

[BechMeister]

-=R&D_UPDATE=-
Duna Sample Return Mission

Oooh Do I have a great update for you guys! I am really proud of these vehicles!

So I looked more into the Mars Sample Return mission. Even though I was  quite familiar with it (I really rute for all the aspects to be completed.. But I understand why the scientific world find there are better ways to spend the funding it needs). Still it's a really awesome mission.. and the more I looked into it in detail, the more I wanted to "replicate" it.

Like I said I knew about the role of the Perseverance Rover - as well as the idea of how to return the samples to Low Mars Orbit and then fly it back to Earth. But I never looked into what rocket launched Percy actually. But looking for inspiration I learned it was the Atlas 5 rocket that got the rover to Mars, as well as the transfer stages.

I decided to keep the rover from the unlaunched Challenge 6 design, and then start by designing the Lander. From there I would design the Vehicle that would bring the sample from Duna to Low Duna Orbit first, then the vehicle that would bring it from Low Duna Orbit to Kerbin. And from there, the rockets that would bring all 3 vehicles to space and to Duna.

So without further ado, lets get through the design process:

The Sample Return Lander:

It all started with me seeing this concept for the Mars Sample Retrival vehicle:

Early Conceptual drawing of a Mars Sample Retrieval Lander. (Image credit: NASA) - I believe they wanna toss the rocket into the air now rather than launch it from a tube.

There were 2 key features I noticed that I really really thought was clever:

1. The "warhead" of the rocket can be loaded directly by the rover.
2.  The rocket is lying down - meaning a flat, compact design.

Since the challenge 6 rover had a xs docking port in the center. I could build a lander with a tiny 2 stage rocket, Lie it down and have the rover "load" it with the Science Data it would pick up by docking to another sx docking port. Since science data is transferred from vehicle to vehicle.. It meant that the stage broad home could be as little as a probe core.

And if you remember the challenge description: 

On 5/10/2024 at 4:44 PM, BechMeister said:

If the Lander is multi-stage, the stage with Probe Core must be returned. Otherwise the requirements are the same as in Challenge 4

That's exactly what we are doing. 

So I build a relative flat design with a rocket ramp and a 2 stage rocket with enough Δv to get into DLO. I used some inspiration ques from the lander from Challenge 4 and made the landing engines the landing legs. I used the bigger Ox-10c solar panels - because that looked more like the ones on the MSRL concept. The final design looked like this:

The rover from the challenge 6 vehicle and the new lander inspired by the NASA concept.

Now I just had to make sure I could have the rover connect to it. It was possible by setting the two front sets of wheels on max spring setting, and the rear wheels on min - just like when docking to the overengineered challenge 6 rocket I showed last design round.

Its not a perfect fit - but good enough if you ask me.

Now the next problem to solve was how to launch the rocket. At first I contemplated doing the toss maneuver: have some small rockets throw the rocket into the air and then engage the rocket engine and fly up. 

How ever If I could angle the rocket up, I could build a holder for the parachute to slow down the lander. At first I tried landing legs with different variation in spring strength and or size. But it was not enough, or was really clunky and ugly. 

I cursed for a while because we really lack parts that allow us to actuate pieces. but then remembered that Aerobreaks can vary in pitch.. I figured if i put one bellow it and some legs on the end of the ramp I could build a tripod and use the aero break to angle the lander up! And it worked flawless - you just need to manually adjust the angle, because it's moving to fast on its own... This is the feature I am most satisfied with  After that It was just a matter of testing if the rocket would break free no issues, and spoiler alert. It did 

 

I thought it looked cool on the NASA concept with the 4 fuel tanks - but I did not need that much fuel to stick the landing and send the rocket off - so I decided to load the rocket on without fuel - to save the kilos. The lander has enough fuel to fill the rocket and land at the same time. - It takes a little more than ½ the total fuel reserve to fill the rocket... So there should be more than enough to stick the landing.

Sample Accent Stage:

1^st Stage -  48-7S "Spark" engine - 748 Δv
2^nd Stage - LV-1 "Aant" engine - 685Δv

Total: 1433 Δv

Weight:

The lander total:  1.91t
Sample Accent Stage: 0.79t
Sample case (probe core):  0.33t

Now that the lander was made I felt the next natural step was to design the vehicle that has to bring the probe core home from Duna to Kerbin. 

If you wanna see the staging of the rocket in detail, see spoiler section bellow:

Spoiler

The rocket takes off. - some times the lander breaks in the process, but at this point its done its job.

another angle.

stage separation. - 2nd stage has no chance on Kerbin.

the probe core by itself - test for parachute.

chute deployed.

chute deployed  - the probe core falls at a pleasant ~6 m/s

Sample Return Vehicle:

The sample return vehicle 

So - Because the vehicle that will bring back the sample from the real MSR mission uses Ion engines - I decided to make a Ion engine vehicle. Surfice to say... I did not enjoy the slowness of the vehicles with ion engine.. So I decided to pack as many Ion engines I could on a vehicle and still power it. With 2x SP-XXL "Colossus" solar panels I could power 6 Ion engines at 100% thrust, and 1 engine at 75% - giving me as high a thrust to weight ratio as possible.. I will still have to take multiple boosts around Kerbin before I will leave its SOI.

The vehicle consist of 2 sails, a z200 battery of 200U a RC-00S1 core 2x PB-x150 fuel tanks - giving the rocket 4852 Δv. Most importantly, the vehicle has the "sample deorbit module" - a heat shield for the return deorbit.

Bellow - Sample Return Vehicle - Above: Sample Deorbit Module and Sample Case(probe core).

It should give me ample of Δv to get to Duna and back again. I do wonder though If I should go for a very high Duna Capture orbit - where the velocity will be low... Since I will otherwise fear that I wont have time to break the orbit. The rover that skimmed the surface at 4km was getting up to 2500 m/s - I doubt the Ion engine will have time to de-accelerate those speeds? - Not that It would survive going so low any way.

We will see.

Now I had my rover, I had my lander and I had my sample return vehicle. Time to find out how to get it all into orbit.

Launch Vehicles:

The Sample Return Vehicle:

Since the Sample Return Vehicle only clocked in at 3.24t. - I figured a reworked 2nd stage for the glider rocket would be ideal:

1st, 2nd and the sample return vehicle.

The new 2nd stage has enough fuel to get the probe into orbit, and then de-orbit itself. has a heat shield as well as parachutes. Because the engines are very heavy, the vehicle is a bit problematic in case of center of mass being to close to the rear of the vehicle. I hope that adding 3 breaks will help me steer the vehicle.. But experience tells me otherwise. We will see though - I dont mind to be wrong in this regard.

This Kerbin to LKO vehicle is not that exciting. So moving on to the next.

Rover and Lander:

I saw this nice picture of Perseverance rover and its capsule: 

From bottom: Heat shield - Rover + Decent Stage + Back Shell - Cruise stage.

I know I said I had decided not to use heat shields - since they were very heavy for how little protection was needed to go through the atmosphere. But It is just very difficult to designe a nice blunt shape without them. So I decided to add the heat shield any way, but turn the oblateness all the way down to 0%. Then I build the back shell with a faring and because you can't add stuff on top of farings, I added the cruise stage below the heat shield:

 
Left: Vehicle Capsule and Cruise Module separated - Right: Vehicle capsule and Cruise Module assembled. - Notice the launch vehicle in the background.

I think the design is very satisfying to look at. The stage has 539Δv - enough to make course correction and solar panels to keep it powered. It's hard to believe - but the two capsules actually have the same total weight - I had to share a screenshot to prove it:

I did not intent for this - but its really cool i think.

To get the capsules out of Kerbin SOI - I decided to take the 1st stage for my Heavy Fuel Vehicle again and build a 2nd stage that had enough power to get the capsules to the edge of Kerbin SOI - to then fall back down and splash into the ocean.

The result was this:

The 1st stage has enough Δv to launch the 2nd stage into a sub orbital trajectory of 1000 m/s - The 2nd stage with the SC-TT "Labradoodle" engine has 2049Δv - enough to get the capsule to the edge of Kerbin SOI - and then about 500 Δv to aim the decent.

Coming in from the edge it's going to be going very fast. - like the 2nd stage for the Sample Return Vehicle - this also has issues with its center of mass. I hope that the 6 large grid fins will help it fall through the sky with the heat shield front.

<<<<<<<<<< Moving Forward >>>>>>>>>>

I am really happy with these designs and I am really looking forward to give it ago. Its kind of cool to emulate a real mission.. And I actually really enjoyed "building small" specialized vehicles. 

I actually dont feel a need to attempt flying the vehicle I originally designed for challenge 6 - If people really want to see me launch it I will do it.. but if it has no interest - I'll just put it in the R&D bin.

Stay tuned for more!

Next up - a triple launch... and the answer to the question if I have the patience for Ion Engines.

[BechMeister]

-=Duna Sample Return Mission=-
- Part 1: Destination Duna -

The target area for the Duna Sample Return Mission.

<<<<<<<<<<Foreword>>>>>>>>>>

The amount of information that accumulated during this initial mission step... was starting to get to a point were, if I decided the entire completion of the challenge had to be included, the post would become excessively long (even for my standards).

It felt naturally to conclude part 1 with the (to a varying degree) successful arrival of all 3 vehicles to Duna SOI. 

I hope you'll all find what I learned, doing this, engaging and interesting to read.

 

<<<<<<<<<< Mission Tasks >>>>>>>>>>

A. Launch Duna Rover and Duna Sample Retriver into a Duna transfer orbit, and return 1st and 2nd stage - Success

B. Launch Duna Sample Returner into a LKO, and return 1st and 2nd stage - Success

C. Land Duna Rover within the Target Area on Duna - Success

D. Land Duna Sample Retriever within the Target Area on Duna - Success

E. Get Duna Sample Returner into LDO ~60km - with enough Δv for the return trip - Failure

<<<<<<<<<<< Lessons Learned; Lessons Identified>>>>>>>>>>

 

Goal Post A: Launching the Ground Vehicles

Duna Sample Retriever being launched into orbit - 5 days after the Duna Rovers succesful launch

The launch of the 2x ground vehicle was succesful. I was not too worried about these launches as I had a very good understanding of the behavior of the launch vehicle. I scheduled the launch to coincide with the "optimal transfer maneuver node position" (I decided to wait for KSC to be in the ideal position to launch the rover.) 

Normally I always launch the vehicle into LKO first. Then find the optimal place on the vehicles orbit, to do the transfer burn that will take me out of the Kerbin SOI. But I decided that I did not need to take such precaution, and launched the vehicles directly from the pad and into a duna transfer trajectory. 

KSCs position in relation to Kerbins orbit around Kerbol.

I was however still very conservative. (could have launched later) I wanted to perform the transfer burn around Kerbins retrograde around Kerbol - roughly the area K.G.01 is located on the image (the orbiting object) - because that would push my prograde towards the travel direction of Kerbin - placing me on the outside of its orbit, and towards Duna. (i'm sure you all know what I mean)

1st stage has reached the target velocity and is preparing for stage separation and return to KSC

The 1st stage had no issues pushing the much lighter vehicle into its target suborbit. Normally it is very slow to gain altitude and needs to cut the engines at ~900m/s - But I had ample Δv left to push it up to a 1100-1200m/s before performing stage separation and the flip maneuver. (as mentioned in a previous post - the 1st stage usually launch a much heavier vehicle)

Stage separation and flip maneuver - it would be days before the 2nd stage would make it back to Kerbin.

The stage separation was successfully performed and the 1st stage would soon find itself back on the pad - while the 2nd stage would start its climb, to push the Duna Rover Capsule out of the Kerbin SOI - It would then be ~6 days before it would reach AP and start its fall back towards Kerbin. Which coincided with the  Duna Rover Capsule escaping Kerbin.

With a buffer of 6 days it felt safe to launch the Duna Sample Retriever. I hoped that 6 days would give me ample of time for the capsules to arrive at Duna in a manner where I could land them both in a short succession. I was some what successful - for more details jump to goal post C

Both 1st stages was successfully returned to KSC - and even on the first go! - see spoiler section for details:
 

Spoiler

Launch and Landing of the Duna Rover 1st stage:

1st stage successfully landed "on the pad" after toasting a few trees.

Launch and landing of the Duna Sample Retriever 1st stage:

1st stage of the Duna Sample Retriever back on the pad in KSC.

2nd stage of the Duna Sample performing Duna Transfer Burn.

The 2nd stage would then perform an initial burn - aiming to get its AP into the vicinity of Kerbins retrograde vector. Like I said earlier, I was conservative with the launch window - giving me a coasting phase, and ample time to plan the Duna Transfer Maneuver:

Left: Duna Sample Retriever Transfer Trajectory - Right Duna Rover Transfer Trajectory.

After the 2nd stages had performed a majority of the transfer burn to Duna. The stage would separate and burn retrograde to push its PE back within Kerbins SOI. After that it was just a long  coasting phase until PE - at which they would perform a maneuver putting the vehicle into a suborbital trajectory, and end up in the oceans on Kerbin again. 

The Duna Rover Capsule performing the rest of the Duna Transfer Burn.

Upon stage separation the Duna Rover Capsule and Duna Sample Retriever capsule would spend 428Δv and 403Δv of their total 525 Δv getting a intercept trajectory with Duna.

Once out of Kerbin SOI it was time to do the fine maneuvering, putting the two capsules into a crashing trajectory with Duna - My theory was that If I aimed at the center of the planet, then I would arrive more "centerly" on the planet, and then when I did the final aiming maneuver for the target landing zone - I would get an suborbital ark that would hug the polar atmosphere more tight than if I came in above the poles. Which would result in a PE on the "back side" of Duna, since dipping into the atmosphere would happen after they passed over the target area and subsequently result in a much more equatorial landing. The theory was some what right.. although I probably have to aim south of the southpole to get the effect I was actually looking for. Future missions will tell.

After the succesful transfer burn to Duna there was only one thing left to do. See if the Grid fins on the 2nd stage would be enough to keep the heat shield pointed in the right direction on reentry.

Duna Rover second stage successfully landed in the ocean of Kerbin.

The Duna Rover 2nd stage reentered the atmosphere with 400 Δv left (remember it's 400Δv after shedding the weight of the capsule)  - making it able to keep the heat shield pointed down. However it did splash down with 15 m/s - meaning it only landed unscathed because it landed in the ocean.

To see if the 2nd stage would go sub 10 m/s if it was empty the Duna Sample Retriever 2nd stage was spending its last Δv making sure to target ocean.

The lost mass from the front, meant that it was no longer able to point prograde - but it survived the angled reentry. How ever it still splashed down at 12 m/s.

Meaning that a re-design has to be made for the stage. I have a feeling that I get better performance from aerobreaks when re-entering. So I'll try change the grid fins for aerobreaks and add more parachutes.

The chances of hitting land is slim.. but it would be annoying to lose a perfectly good engine because of a hard landing... and It is very hard to gauge where you land from the edge of Kerbins SOI

Goal Post B: Launching the Orbitter

The Duna Sample Return vehicle being launched into LKO

According to the KSP Δv roadmap - the tour- from LKO to LDO is ~1700 Δv. By getting better at finding the optimal launch window for Duna I had cut my Δv consumption on a Duna Transfer from 2000+ Δv to around 1200Δv (observation from the failed duna rover mission.)

The Duna Sample Return vehicle had almost 5000 Δv in total- meaning that I should have 1600 Δv to spare, since the return trip would be a collision trajectory with Kerbin.

It should be no issue to launch it to a LKO and have the vehicle leave the Kerbin SOI on its own power. I wanted to do this to see how many passes around Kerbin it would take to get it on to a Duna transfer trajectory.

Stage separation - the first stage is performing its flip maneuver, engines still glowing hot red.

Launching the small ion driven vehicle into orbit was going to be a walk in the park - since the 1st stage, and triple LV-909 "Terrier" engined 2nd stage (as I am sure you know by now) is well understood and tested. - it is the glider without wings after all.

The 1st stage was of course returned safely to the pad. This time I made sure to burn enough  Δv that I would end up with the around 300 Δv needed to break the fall and land... not taking any chances that it was a weight issue that caused the leg to break off last time. - look at the spoiler section to see succesful launch and landing of the 1st stage.

Spoiler

1st stage safely at the pad again.

the 2nd stage coasting after releasing the Duna Sample Return vehicle - blinding the camera with its huge solar panels providing the vehicle with 67,76 EC/s

The 2nd stage boosted the vehicle into an elliptical orbit, reserving only a 100 Δv to get it back into a suborbital trajectory. The 7 ion engines of the Duna Sample Return vehicle would then be tested for good, checking how many passes around Kerbin it would take to get enough power to leave Kerbin SOI. 

Duna Sample Return vehicle doing the last corrections before coasting to Duna - waving Kerbin goodbye

Amazingly enough it would only take the vehicle 5 orbits to gain enough velocity to escape Kerbins SOI. However.. either the Δv readings for the vehicle is wrong, or I have been super inefficient at doing the transfer burn to Duna. Because once the Duna Transfer Trajectory was set - the fuel reserve was halfed but the Δv readings were ~1/5th.

The Duna Sample Retriever vehicles route to Duna - notice that the vehicle has lost 3707/4852 Δv on the transfer maneuver. But have only halfed its Xenon reserve.

The Duna Sample Retriever vehicle were also aimed to arrive at Duna at the second intersection point of the orbit - giving the rover more time to pick up relevant samples from the target area - to be send home for analysis. Checking the site for habitability for future missions.

2nd stage re-entering high above Kerbin.

Although the 2nd stage was the last to get into orbit around Kerbin, it would still be the first vehicle to touch down on Kerbin again. It had a soft landing in the desert on the continent west of KSC. The 3 aero breaks proved sufficient at keeping the nose pointed forward - albeit the vehicle were still having a bit of fuel to make the nose heavier. 

But were the vehicle had sufficient drag to keep the engines out of the plasma cone. The heatshield did not ample protect the faring disc right underneath it. Resulting in the piece failing on the final stretch, just before sheading velocity enough to not "be safe".

Fortunately Kerbals make their vehicles of sturdy stuff! So even though the heat shield was dumped from the failing farings disk. The loss of the heatshield drastically reduced the speed! the vehicle did not suffer any further failures and landed perfect.

 
The 2nd stage waiting to be retrieved in the deserts to the west of KSC.

An easy solution to this issue will be to move the faring disk Infront of the heat shield, and add a decoupler to drop it once re-entering?  or swap places and use it as a form of pre-heat shield? Avoiding further vehicle complexity.

Goal Post C: Landing the Rover

Duna Rover intercept trajectory - running low on fuel.

For some reason the Duna Rover's, last adjustment of its trajectory to hit Duna, spend ~100Δv of the ~150Δv (that were left after leaving Kerbin SOI.) Whereas the Duna Sample Retrieve vehicle would successfully do the same maneuver at less than half the same Δv.

Even so, I was not worried - 52 Δv was more than enough to do the final corrections once inside the Duna SOI - provided I did them upon entering the edge of the SOI (if you didnt know, the further away from the body you do your maneuver, the cheaper it is).

Aming the vehicle - so it would land on the target area - would become much more challenging though. Especially if it would be on the night side since its hard to see the terrain features in the dark (and spoiler alert - the target area would be on the night side).

However.. as a stroke of fortune out of missfortune. The Duna Rover were not going to be the first vehicle to arrive at Duna. Even though I had given it a 5 day buffer it had still been overtaken by the Duna Sample Retriever:

Vehicle order from left to right:  1: Duna Sample Returner - 2: Duna Rover - 3: Duna Sample Retriever.

This meant that the Duna Sample Retriever capsule - which had 115 Δv to play with, could afford to do path corrections all the way down to Duna, and land on the right spot. And then the Duna Rover Capsule could look at the Duna Sample Retrievers relative position to were it were heading and do relative precise maneuver corrections to the target area from a great distance.

Duna Rover closing in on Duna - Ike visible in the distance.

It all paned out great. To make sure I got the right point, I quick saved upon entering the Duna SOI and then allowed the vehicle fly within 200km of the planet. Then I checked where the Duna Sample Retriever were located in relation to the spot of the Duna Rover impact. Quick loaded and adjusted the course onto roughly the spot the Retriever would be in the 2d and 5h it took to get to Duna. The maneuver costed less than 10Δv.

Cruise module separates from the capsule once the final aiming has been done.

Once within 100 km of the landing area, I made the last adjustments, decoupled the cruise stage and enjoyed the show. - see  section D for capsule performance thoughts

See spoiler section for slideshow of the capsule entering Dunas atmosphere.

Spoiler

The aiming point - notice that I overshoot the target - this is because I know I want the parachute to deploy over the target.

I flipped the capsule as the faring bleed of way more energy than the heatshield, which seems to work more as an speeder.

After the Capsule decoupled from the rover, the rover did have some issues though. The lack of RCW meant that it was rolling uncontrollable on the way down, and would not stabilize before hitting the ground. I could somewhat control the rate, with which the vehicle was falling, by firering the landing engines for the durating the engines were pointing downwards, as seen here:

But as you can see it was not optimal.. luckily the Rover landed "successfully" and by a stroke of luck.. it rolled over, onto the wheels again. I disengaging the decent stage ASAP the wheels were all level with the ground... I was simply afraid the stage was making the rover top heavy and it would fall again. 

In the end it all panned out and the Rover landed only 5.7km away from the Duna Sample Retriever. - Mission Success!

Kerbol dawning on Sol 1 of the Duna Rover mission.

Goal Post D: Hitting the Target Area.

Duna Sample Retriever after the final course corrections - all the Δv spend.

As mentioned in Goal Post C, the Duna Sample Retriever were the first to reach Duna. Once inside the SOI I saw that it would take it 2d and 5 hours to hit the surface. I looked at the position of the Challenge 2 lander to the target area, and tried to roughly aim were I thought the place would be within 2d. and 5h. - I really wish the game had a tool that allowed us to see future rotation when planning a maneuver.

Then periodically on the way down I would fine tune the landing site. Until I was only 200km from the surface. At which point I believed I could do the fine tuning of the landing and ditch the Cruise Stage.

After that it was all about figuring out how the capsule would perform on the way down.

The Duna Sample Retriever Capsule after ditching the cruise stage.

The capsule performed well, although, just like the Challenge 2 Lander, It accelerated for a long time. In the end I had to perform a flip maneuver to break the fall - It seems the heat shield work a lot more like a speeder than a break. One should think that the blunt shape of the heatshield would make it break more.. compared to the pointy farings. But It may just be me thinking too much of Dunas thin atmosphere.

See spoiler section for the hot reentry:

Spoiler

The faring sustained the final speed drop facing forward and were jettisoned:

Duna Sample Retriever dropping the capsule and preparing for landing.

I had some issues were the ditching of the faring, within the atmosphere, would severely warp the assent stages. It made me re-do the landing several times as I was sure it was the issue were if you time warp with the vehicle SAS set to point to a direction (like prograde) it can warp the vehicle (same bug mentioned in the CommNet satelite deployment).

I tried disable all RCWs on the accent stage, so It could not bend the stage into a wrong shape during time warp. Then made multiple Quick Saves - always dropping the faring afterwards to check if the vehicle had warped - before quick loading and proceeding the landing.

I got all the way to re-entry.. were I noticed the warp happened from the decoupling within the atmosphere. To combat it I made the vehicle flip one last time before decoupling, and decoupled as the ascent stage was pointing roughly prograde. It warped a tiny bit.. but not so much that it clipped into the launching ramp (which it did before, and i was sure would result in a catastrophic failure) 

Lessons Learned; Lessons Identified - use struts. I am sure its a bug.. but since struts break when placed across a decoupler.. I can always strut the pieces in place.

After that drama, it was all about deploying the chute and prepare the landing.

Duna  Sample Retriever performing landing burn.

The lander touched down no issues - I turned off the lights and then waited for the sun to come up before deploying the solar panels. I had to put the stage into hibernation as it does not have enough battery power to make it through the Duna Night. I dont see it as an issue - since the challenge does not state that the vehicle needs to be able to last a Duna Day.  It can launch the accent stage during the day time once the time for that arrives.

Duna Sample Retriever - safe on Dunas Surface, generating power.

After a short test that the accend stage could launch without failing, I saved and uttered a sigh of relief - The hard part was done - The Lander had hit the target area without circularising its orbit first and without breaking. Soon the rover would join it.. and then it was just waiting for the Return Vehicle to get into a LDO before concluding Challenge 5 and 6.

 

Goal Post E: So close and yet so far

Duna Sample Return vehicle circularising its orbit.

The experienced KSP player will have guessed that this is as far as the journey went for the retriever. I know I said I allowed it to get its rendezvous with Duna on its second cross of its path. the II: symbol on the maneuver node. But I waited the time and pretend that I performed the survey of the valley in the mean while. I had to know if the returner would have enough Δv to finish the mission. Or if a sample return had to be postponed another 4 years. Alas the latter was the case.

I made 2 important lessons though:

Lesson A: Capture Burn

I learned i was right about taking a path that brought my PE high into Dunas SOI. I tried to break and stay within Duna on a trajectory that brought me close to the planet ~100km altitude. I did not have enough Δv to circularise the orbit. I could reverse my orbit, but not circularize it.

So I remained far out:

Duna Sample Returner capture maneuver

As you can see it would take a majority of my Δv to capture Duna. If any one has any council on how to perform this part at a Δv discount, I am all ears. - and before you say aerobreak, I dont think Dunas atmosphere is thick enough that it will break the vehicle to not break out of the SOI again.

Lesson B: Solar panel effectiveness.

Around Kerbin - the two SP-XXL "Colossus" produces a total of 66.76 EC/s. But around Duna the two sails only produce 31,56 EC/s - more than a half in reduction. I did not expect the effect to drop that much - Duna is not that much further from Kerbol than Kerbin. 

The result was that the vehicle could only use 3½ of its 7 ion engines around Duna. In other words over half the engines were dead weight this far out.

Maneuver to LDO:

Even though the vehicle had arrived at Duna with no means to complete the mission, I still spend the time to find out what was the optimal way to lower my orbit. I arrived at the conclusion that the cheapest way to lower my orbit was this:

A. Lower the PE to the target distance of ~60km: 

• 3 burns at AP - duration: 3 min

B. Lower the AP to the target distance of ~60km:

• 5 burns at PE - duration: 3 min - 1.100km altitude
• 4 burns at PE - duration: 6 min - 150km altitude
• 1 burn at PE - duration: 4 min - 91km altitude
• 1 burn at PE - duration: unknown - ~60km altitude.

If any one have any better solutions to get the orbit down cheaper - I am all ears.

The Duna Sample Return vehicle in LDO

In the end the vehicle successfully lowered its orbit from the edge of the Duna SOI to a ~60km circular LDO. 

However, as is evident from the screenshot. It completed this leg with far to little Δv to bring the sample back to Kerbin. - After I had learned what there was to learn, I spend the last 173 Δv to de-orbit the lander.

<<<<<<<<<< Moving Forward >>>>>>>>>>

The Ground Vehicles were succesful in their designs and execution - the retriever needs more work. How ever I have already redesigned the vehicle from the LL;LI in Goal Post E. - Reduced the number of engines and increased the fuel capacity.

As the post is already really long, I will be pushing that update into the Part 2 of this mission.

Next post will be the challenge completion of Challenge 5. I will take samples in the target valley - to determine if it's ideal for a science outpost to continue further excursions.

Stay inquisitive, stay engineous - until next time!

Final landing places of the Duna Rover, and the Duna Sample Retriever.

Edited May 20, 2024 by BechMeister
relinked all image, as they got formatted weird

[BechMeister]

-=Duna Sample Return Mission=-

- Part 2: Survey of Target Area -

Map reconnaissance of four possible sites for settlements.

<<<<<<<<<< Foreword >>>>>>>>>>

The challenge description called for the Rover to "cover some distance" - I decided that I would take the opportunity to survey possible landing sites for the manned mission to come. There were a few sites that were interesting to me - for various reasons. 

Surveying the 4 sites took a few evenings, listening to podcasts and only playing with half a eye on the screen. It covered 75km and I would say that it qualifies as "covering some distance"

More on that bellow:

 

<<<<<<<<<< Mission Tasks >>>>>>>>>>

 

Survey Site A. - Sheltered Canyon - Success

Survey Site B. - Sheltered Valley - Success

Survey Site C. - Small Canyon through the Ice Caps - Success

Survey Site D. - Open flats - Success

 

<<<<<<<<<< Lessons Learned; Lessons Identified>>>>>>>>>>

The rover taking a sample on site D.

The Mission In General:

Since Goal Post A to D has a lot in common - I have decided to write a general section of the Lessons Learned; Lessons Identified (when it comes to the rover) and then a specialized section for each site. (more like flavour posts)

The Rover:

Percy - the rover - performed the task very well.

On flat terrain it could sustain a speed of ~ 10m/s - albeit it is not advisable, for the sole reason that, for unknown reasons it would occasionally act like it hits something invisible and lose control. If it crashes with ~10m/s there is a high risk that pieces will break on it. A battery is bad, since it just have enough power to run the WSRL-01 radiation survey - Some times it would break off a reactor unit... Which definitely would result in the survey site being unsuitable for a manned mission.. but also slow down progression - since the Percy would not have the power generation for continuously driving.

Percy thus performed better at 6 m/s - were the periodically loss of control could be corrected via contra steering.

Its cross country ability is quite good - better than expected! The roughest terrain feature it had to navigate was a 45° slope - it needed a run up to the obstacle - but successfully crossed it in 3rd go as seen here:

 

Still a lot of Jank: RCW is a must

The rover overall still performed a lot better than my Minmus Rover - I have a feeling it's solely because Duna has more gravity, or the rover is significantly lighter - which gives the vehicle more authority when driving, and less mass and inertia to shift around.

That being said... the vehicle really could use some RCWs. There were several times were - when the vehicle lost control - I had to hit the break and maneuver hard to balance the vehicle on a single wheel.. or have it tumble around and do my best to make it land back on all 6 wheels. The antenna was actually great help, since it made it less likely to land on the back...

Percy driving in the shadow in the Canyon of Site A

I know I've said this before in the Minmus blog - I really dont enjoy the wheeled vehicle gameplay..

I think the issue comes from them not having a seperate mechanics for ground based vehicles..? at least it seems to me that it is less based on the positions of the wheels.. and more based the velocity vector made by hitting "direction keys". 

The vehicle responds to the prograde, and not the position of the wheels.. which means that you end up drifting if you only look at wheels and not the prograde... the key to driving rovers, seems to be this: Gain momentum - do small adjustments and everything goes fine. But most important! Add Reaction Control Wheels - set them to activate via. a action command to roll and pitch the vehicle it goes wrong. The rovemat part does not have RCWs.. which would be fine if it wasn't for the invisible objects that kick the vehicle off course every once and a while.

 Survey Mission:

Estimated path driven on the Survey Mission. - brain fart - ofcourse its only 6 samples.

In the end the different places of interest were examined - looking for good spots for a manned base with the following criteria to meet:

• Leveled ground - we dont want the coffee cups rolling off the tables
• Access to sunlight 
• Shelter from the environment - storms etc.
• A cool looking backdrop for a manned mission.

The last one being the most important of course  - bellow you will see my assessment of the 4 sites in each their spoiler section:

Survey Site A:

Spoiler

Survey Assessment

The Canyon of Survey Site A is only partially suited for manned mission. Although the location is a great backdrop with black Volcanic sand and rolling glacier hills to either side.  The east - west running ridge potentially occludes the canyon for much of the day.

A detailed walkthrough of the survey can be seen below:

The rover leaving its touch down location close to Site D and move towards the canyon of Survey Site A.

When I saw the canyons carving through the ice of the Duna North Pole. I thought it could be a cool looking place for a base camp - My biggest worry was that the sun would be occluded by the mountain ridges and the terrain too hilly.  

The path to the canyon would take me over the glacier - which gave an opportunity to get a Ice Sample. (to test for suitability to get drinking water of course)

Sample I - Ice Sample from the nearby glacier.

After that the path quickly took me down the canyon. Once in the canyon, 2 suitable locations for settlements were found: one at the entrance (Sample II) and later at the fork leading to Site B and C. (sample III)

Percy on top of the glacier, looking down into the canyon

Percy taking Sample II 

The sample II location was leveled grounded and in a rather beautiful valley. However the sun was very close to the glacier ridge, as seen below:

Percy moving on to Sample Site III while admiring the midday sun peaking over the ridge.

Not to worry, the canyon was leading to Site B any way, and subsequently would be thoroughly surveyed. - Percy went onwards to Sample Site III:

Percy traversing black volcanic ground in the fork that leads to site B and C

The fork in the canyon splitting towards the high ground depression of Site C and the big valley of Site B was less leveled - but it opened up, meaning a greater area was available for a settlement and the ridge was less dominating.

Percy in the canyon fork.

Survey Site B:

Spoiler

Survey Assessment:

Site B is very suited for settlements - the valley has multiple flat hills to the north - meaning that getting access to sunlight during the day is not an issue. - the only issue is possible landing sites for the spaceplane mentioned in challenge 8

Percy arriving at Survey Site B - Ike low in the horizon

As you can see Survey Site B is mostly the same black volcanic sand that dominates the canyon leading to it.

another angle of the Survey Site B

The valley is vast and covers a big area - well suited for confined research. And the Sun would be high in the sky. 

Percy performing sample extraction IV

Percy on its way up the glacial slope surrounding the sheltered valley - giving a good view of the location.

Survey Site C:

Spoiler

Survey Assessment:

Site C is not at all suitable for base building. Not only is it not at all ice free (as seen on the map viewer) - it is also just a slight depression on the ice, so cratered that you can't really see were the depression is running unless in the map view or zoomed out.

Percy leaving the valley of Site B behind.

Sample V in a crater - what on the map looked like was dry land surrounded by ice

same location in the map view

After navigating the hard glacial terrain. I finally reached a ridge - that had a somewhat gentle slope - towards Site D.

Percy looking out to the vast open of Site D

Survey Site D:

Spoiler

Survey Assessment:

Site D has plenty of flat leveled terrain. Its gentle clay formations, well suited for base building. The terrain opening to the south meaning no features will obscure the sun. The only negative as I see it is the area is less sheltered from weather fenomena. But it offers great opportunity for excursions and operations further south.

Percy navigating the gentle slope down site D.

Percy taking Sample VI - with the glacier of Site C in the background.

Percy on its way to the Duna Sample Retriever with all the science

After the 4 sites had been investigated, I concluded that the best site would probably be Site D. It came as no surprise to me - but I wanted to see the other sides first before ruling them out.

Site D wins because it has the best potential of all - since it also provides good flat terrain for landing the space plane of challenge 8 on.

Needless to say - shortly after Site D had been successfully surveyed - The Rover arrived at the Duna Sample Retriever. Finishing its 75km tour.

 

<<<<<<<<<< Moving Forward >>>>>>>>>>

Next up will be a R&D Post containing the redesign of the Duna Sample Return Vehicle, as well as the base modules for the settlement that need to house the Kerbins in the time for the transfer window back to Kerbin arrives.

 

 

Edited May 23, 2024 by BechMeister

[BechMeister]

-= R&D_Update =-
- Duna Settlement and fixing the Sample Return Vehicle -

Duna Base Element being tested on runway 1

- Boots on the Ground -

With challenge 6 about to be bagged - it is time to prepare for challenge 7:

  

On 2/28/2023 at 9:15 PM, OJT said:

7. Strangers in a Strange Land

Land a Kerbal (or Kerbals) on Duna and then bring him (or them) back. The method (Direct ascent vs. Orbit rendezvous) is up to your choice. If you send multiple Kerbals, all of them must return home: leave no one stranded!

Now... I know Jeb is more than willing to sit in his suite for 8 odd years - he is made of sturdy stuff indeed. But It has always felt a bit "wrong to me" that you dont need base elements for prolonged stays at an area.

Aaand let's face it - after launching a mission to Duna in the ideal Kerbin - Duna Transfer window, you have to wait ca. 2y and 24 days for the next Duna - Kerbin transfer window to happen. (judging from me sitting with a goniometer on the screen and counting days) - I used this for the angle references:

Now,  of those 2y and 24 days, ~300 days is the travel time - So a settlement "just" need to support the crew for 1y and 98 days? (if my math is correct)  - In any case... I think it will be nice to spend that year in a HAB module, rather than a lander. (and please correct me if i'm wrong... about the timings)

So it is time to build a temporary science outpost:

- Designing the HAB Modules -

In my Overengineered Minmus Mission I experimented a little with making HABs - It was a "pretty big base" (or at least a high parts count) consisting of 4 HAB modules, a rover and 2 landers. That could house and service a 10 Kerbal crew. It looked like this:

Base Camp One on the surface of Minmus.

Building and shipping the base for Minmus taught me a lot of things about "base building" - but most importantly that its very easy to build things that gets a parts counter that kills the frame rate! My framerate around Base Camp One would be something like 5 fps. Now I still dread the 3 fps I had during my Minmus Mission (when the base was still docked to the vehicle flying it to Minmus), so I knew I wanted a smaller base for less Kerbals... and send it piece meal.

I really liked the design of the temporary hab modules in the Martian -which had these proportions:

Screenshot from The Martian - seeing their base from above

As you can see it consist of the big dome, a small hab module on the side, as well as a few entrance modules and a solar panel farm - I really wanted to build a dome myself... but the big MK3-L "wanderer" capsule offered a chance to build it while keeping the parts counter down. I wanted to have the asymmetry, and tried to make the entrances with the small crew tubes - but the only way to get doors is to use the lander modules. Which limited a lot in how I could design it.

So to keep the parts counter down, and make sure all worked - the complete base ended up looking like this:

Duna HAB module and Rover being tested on the runway.

It consist of 3 modules: a LAB module, a Living Quarter module and a Solar Panel Farm. All the modules are equipped with wheels - so I can connect them once landed - as well as legs to give the base a firm placement on the ground. - LL;LI from the Minmus mission was that the landinglegs helped if the ports were not perfectly aligned... Also it is a potential means to correct inclination in the HAB. (1 year and 98 days on an angled floor would drive me nuts ) 

To support the mission the Crew will also have 2 Duna Rovers.

In the spoiler sections below you will see a rundown of each module:

Laboratory Module:

Spoiler

The LAB module is were all the samples will be processed, as well as mission control and communication between base crew and vehicle crew out on expeditions. - It also works as the centerpiece of the HAB - connecting all the modules.

Note: on this image the module used 4 small parachutes to land, as well as a 0-10 "puff" engine for a soft landing - on the final model the 4 chutes is replaced by one large as seen here:

Living Quarter:

Spoiler

Crew Quarters - containing bunkbeds for the 6 kerbals and a small kitchen section and housing the primary communication disc.

Solar Panel Farm:

Spoiler

The solar panel farm! because of the position on the northern hemisphere of Duna I decided to angle it 45°. The panels need to be placed so it faces south. The two SP-4w panels can will be able to swivel and some what gain solar energy through the day.

Duna Rover:

Spoiler

The LL;LI from the Minmus mission was that the rover from that mission had enough battery power to get from south of the equator and to the Minmus monument - yes I was insane enough that I drove that distance   

Which was lucky, because that only had a single OX-STAT-XL panel to recharge the batteries - facing up. I quickly found that it was not ideal for power generation - which means that this design now has a single vertical panel that can rotate. 

The rover on Minmus used rocket engines to load itself into the dropships again, which meant It also needed a docking port to be able to refuel the methalox for flying. While the engines also proved very useful on Minmus to navigate steep terrain. The Duna rover does not have engines - so It does not need a docking port. Which also means that it relies solely on power regeneration from its solar panel.

The vehicle is a 8x8 and steers of 3/4 axles: Axle 1, 2 and 4 - The Minmus Rover showed that was the best - the single axle without steering would help keep momentum, when turning at slow speeds in reverse. (for some reason the game always insist on going forward when turning)

- Cruise Stage -

After designing the base modules it was time to find a way to get them to Duna. On my Minmus mission I had these elaborate dropships for "dropping" the base module and returning back to the "mothership" or ICV (Inter Celestial Vehicle). see spoiler section bellow for images:

Spoiler

drop ships  has undocked from the mothership and are landing.

breaking for landing

all the ships has landed

The dropships drop the base modules.

After base assembly the 4 dropships returned to the mothership.

But I now know that dropships add a lot of complexity the ICV, that has to bring the modules and vehicles to and from the destination.

On Duna they also had to be a lot more powerful, than on Minmus, to be able to bring the HAB modules to and from LDO to the surface and back again. The added complexity would also bring up the part count significantly... and I want it to be pretty yes.. but please faster than 3 fps  

I decided that it would be better to just put the HAB modules in capsules that could survive reentry on Duna and then just stack the capsules in the order I want them dropped and decouple them in order, then land them one at the time.

The Stack ended up looking like this, and weights ~55t (rounded up):

The Stack - with and without fairings.

These stacks would fit well with a much simpler ICV I developed right after being fed up with my Minmus Mission - let me present the Cruise Stage - ICV Hermes:

The ICV - Hermes 

The cruise stage was designed with a crew transfer module in mind, and has been lying in my VAB gathering dust for a while. 

The Crew Transfer Module consisting of two foldable crew structures that can rotate to create gravity on the tour (the entire craft has to rotate, not ideal I know.. but we gotta work with what we got). As well as two DAVs (Duna Ascent Vehicles).

The crew module weighs 45,6t - going to Duna. and 30,8t going back to Kerbin. The Stack weighs 55t - and that gives the cruise stage 6.290 Δv - which should be plenty. especially considering that it will be unloaded on the way home. (which gives me a chance to see if it needs more fuel to make the tour with the crew module) 

- See spoiler section bellow for a walkthrough of the Crew Transfer Module:

Spoiler

ICV Hermes - Crew Transfer Module:

The crew transfer module is designed with 2 crew pods that can house the Kerbalnauts for the ~300 days it takes to get to Duna from Kerbin. 

It has two modes:

1. folded down mode - with a aerobraking capability. The inflatable heat shield just manage to cover the same diameter as the XXL Hydrogen tank. how ever the distance between the shield and the tank probably means it will be hit by the atmosphere when aerobraking... It probably won't be an issue around Duna -but the future will show if it will be an issue around a body like Eve.
2. Gravity Mode: When in gravity mode, the two DAVs will dock to the extra docking port, and the two crew departments attach so they get maximum centrifugal force when rotating.
   
   It is not ideal that the hab modules are arranged horizontal (as it will mean more G's on the button floor than the top) - but it kept the parts down, and meant it folded neatly behind the heat shield.
   
   The capsule connecting the HAB module can also separate from the main arm and re-enter and deploy chutes in case of an emergency.

The vehicle also hold the two DAVs - which is going to bring the crew safely to and from the surface of Duna.

Duna Ascent Vehicle(DAV):

The DAV consist of 3 stages:

• Stage 0 - de-orbit and landing module
• Stage 1 - ascent tage - takes the capsule out of Duna's atmosphere.
• Stage 2 - Capsule with enough Δv to circularize the orbit.

 

- Testing the Stack -

Since the stack was quite complicated I decided to test it above Kerbin to make sure I would not get to Duna and only half the base modules would work... but first things first - we need to get the stack into LKO.

As of now, my go to solution of getting overly complicated structures into space, is strapping on big solid rocket motors to it until it works... If it was good enough for the shuttle program, it's good enough for me.  The solid rocket boosters work as the stacks 1st stage and looks like this: 

the full stack

I added a 2nd stage with a LV-2000 "Trumpet" engine to get the stack into its final orbit. It has just enough Δv to get it done - I had 13 Δv left when I was in a stable orbit. Once the stack had been fully dropped, the 13 Δv turned into a few 100 Δv - more than enough for a deorbit of the engine. (the margin is still a little too tight, so I will be adding fuel for the final launch)

Testing the Stack: Getting into Orbit

Getting the rocket into orbit was a simple discipline - if not for the tight Δv margins.

Once orbit was achieved. It was time to test if the modules reentry capsules worked as intended. 

Note: In an attempt at keeping the update "short"  *cough cough* I have put the individual performances in spoiler sections - Issues found will be discussed after the individual sections.

LAB Module:

Spoiler

The Lab Module was the first to be launched. To make the XL part fit on top the L part I had to make an droppable adapter:

The stack launches the first stage for deorbit - notice the adapter.

I hoped the 4 x 24-77 "twich" engines could deorbit the capsule sufficiently to put the adapter within the atmosphere before dropping them. But the engines had no effect while occluded by the adapter. I had to ditch the adapter prematurely and proceed with the test.

Adapter plate successfully ditched - how ever it is now space trash.

After that it was a simple matter of having the Twitch engines lower the PE.

The capsule re-enter sequence.

The capsule re-entered flawlessly. The only thing I was thinking about changing was swapping the 4x small chutes for a single big one - I just needed to find a good way to get rid of the chute once landed, since would preferer if the windows were not obscured. - see section about final fixes for reference.

Successful splash down.

Living Quarters:

Spoiler

The Living Quater Capsule decoupling from the stack

Since the LAB Capsules Adaptor Plate connected directly to the heat shield of the Living Quarter Capsule - it meant that the twitch engines were not occluded and had no issues de-orbiting the capsule.

 

The Living Quater Capsule performing deorbit burn.

How ever I quickly found out that the living quarters energy capacity was only that of the MK1 "Explorer" (which functioned as a doorway to the module) - and the re-entry capsule was vastly inadequately powered for the re-entry sequence...

SAS had been turned off - or all the power would run out even before the capsule run through the upper atmosphere - which makes it hard to deploy the chutes. 

Fortunately the craft proved to be very stable on the way down. So even without SAS it kept the heatshield pointed in the right direction. I wonder if it's the conical shape at the back that gives it drag.

Any way, it meant the craft re-entered while maintaining enough EC to drop the capsule and deploy the chutes.

The re-entry of sequence of the living sequence.

When I designed this module I thought 4 RCS thrusters would be adequate to break the fall - looking at the velocity with which it drops on Kerbin, I have now assessed that that's too optimistic.

I decided to replace the 4 thrusters with 1x 0-10 "puff" engine - just to be sure I had a high enough TWR on Duna.

Living Quarter Module safely on the surface of Kerbin.

Duna Rovers:

Spoiler

Duna Rover 01 detaching from the stack

The Duna Rovers were not going to be an issue either, since it consisted of two modules that did not have their twitch engines covered by adapters. Deorbit was done with no issues.

 

Re-entry sequence of the Rover Capsule.

The Δv pool on the rovers are quite small - which meant that the re-entry was so gentle that it hardly lit any flames on the way down. Bleeding off most of the speed by bouncing off the upper atmosphere.

Once through the atmosphere and the chute had deployed it was just a question of waiting until the engines had to "break the fall" (the chute was more than adequate on Kerbin).

The rover landing itself.

After that it was just a question of detaching the rocket motors and have them fly off.

Rover ready for action on the Surface of Kerbin.

Duna Rover 02: See spoiler section - only images

Spoiler

 

Solar Panel Farm:

Spoiler

The Solar Panel Farm capsule detaching from the 2nd stage

The last module of the stack was the Solar Panel Farm. It undocked from the 2nd stage - just like it is going to undock from the Cruise Stage on Duna.

 Like the LAB Capsule before it, the adaptor plate obscured the thrust so much that It had to be ditched in space as space liter for the test to continue.

 

The adaptor plate being left behind in space.

After that it was just a matter of de-orbiting and see how stable it was on the way down:

the deorbit and landing sequence

Even though this module is super light - it still landed with 3-5 or so m/s on Kerbin - which meant that I felt like I had to add some monoprop tanks and a few RCS thrusters - just in case that the thin atmosphere on Duna is found wanting.

Engine de-orbit:

Spoiler

The last thing to test, was if the Trumpet engine could be safely de-orbited and "reused". This little slide show will proof that my parachute placement was rather poor.. as it touched down on the engine and broke it. 

Besides that It worked flawless.. and it should be a simple matter of just moving the chutes further down on the body.

 

Final Fixes from LL;LI from the test:

In the end everything worked except for 2 main issues that needed further testing after fixing. Namely a change on the LAB modules parachute, and the parachute placement on the 2nd stage - as to make it not land on the engine and denting it... 

Then there were some minor issues that can be resolved by adding more batteries and making sure the The Stack is on a sub orbital path when decoupling a stage (where after the ICV will bring itself into a stable orbit again)

Change of parachute on Lab Module:

I thought I could put a big chute on the module and detach it via a decoupler once on the ground.. How ever I forgot that the game does not simulate wind. So I could detach it all I want, it would always land on the top and rest on the roof, like if it had never been detached. Something else had to be done.

The solution was solid rocket engines... the solution is always solid rocket engines.

Parachute update on 2nd stage:

The fix to the parachutes on the engine was just a silly oversight - I had placed the parachutes near the top of the rocket.. meaning that I would keep the heavy engine pointing down. By moving the chutes to the bottom of the vehicle, the issue was resolved. I still did a test however - incase the engine was so heavy it would still land facing down.

But nope it worked - the vehicle was certified for launch!

- Updating the Duna Sample Return vehicle -

Last but not least, an update to the failed Duna Sample Return Vehicle. Since I only had power to run 3 Ion engines at Duna, I decided to reduce the engines from 7 to 3.

This meant the vehicle lost about 1t in weight. After that i bumped the xenon reserve up quite a bit, so it now shows a Δv counter of 9.187Δv. I hope the game is not lying to me this time.. but even if it is only half of 9.187Δv - it should be enough to go there and back again.

<<<<<<<<<< Moving Forward >>>>>>>>>>

Next Duna Transfer Window will be another double launch: The HAB stack and the Sample Return vehicle.

 it should leave time enough for both vehicles to come back to Kerbin before the next launch to Duna. So the ICV Hermes can be refited for the crewed mission. And the Sample Return Vehicle can land the sample on Kerbin for analasys.

Hopefully it will give the Kerbals some weeks to check the samples for anything dangerous - before sending 6 brave souls.

Im sure they will make it... Or they can send a "dont touch the stones" memo via datalink once air born.

Science must be made! and any kerbal would give their left hand - touching radioactive stones - if it propels the race into a further scientific understanding. 

Stay Tuned for more! Next update is the launch update!

Edited May 27, 2024 by BechMeister
clarification.

[BechMeister]

-=ARES I MISSION =-
Stage 0: Getting Ares Base 01 settled on Duna

I have decided to call my manned mission to Duna Ares 1 - Very original I know... I was contemplating something better.. but The Martian is one of my favorite movies... and I dont know what the Kerbals called their god of war in their antiquity - Kebares? 

Any way.. Landing all the base pieces was done "succesful" - or at least in one piece.. But more on that bellow.

<<<<<<<<<<Mission Tasks>>>>>>>>>>>

A. Launch 'The Stack' and dock to the Cruise Stage - Successful

B. Transport the stack to Duna and deploy Ares Base 01 to Survey Site D - Successful

C. Assemble the base on Survey Side D - Successful

<<<<<<<<<<Lessons Learned; Lessons Identified>>>>>>>>>>>

 

A. Launch 'The Stack' into LKO and connect it with the ICV Hermes (CS):

The ICV Hermes (CS) in orbit above Kerbin.

On the above image you see the Cruise Stage (CS) already in orbit around Kerbin. Most definitely build in space - and not launched in a ridicules fashion that requires the involvement strapping solid rocket boosters to a thin walled spherical hydrogen tank.. then having the flimsy wire structure flip regularly to avoid it melting coming through the atmosphere at high mach values.. etc.. no... definitely build in space like any sane space agency would do...

What's that? a secret spoiler section containing photos of the structure being launched exactly in that manner? lies..!

Spoiler

The ridiculousness about to leave the pad.. notice the heatshield on top of the clamp-o-tron.. yes.. the ports does not like to go into space...

ugh.. please look away...

*sigh* - just me flipping the rocket up and down to avoid the top burning up on the way through the atmosphere..

dropping the solid rocket boosters...

there.. in space - lets pretend it was build up there...

*Siiiigh* - it hurts my inner space nerd that I have to launch vehicles build to be light and never see the light of an atmosphere in this fashion..

Well.. It technically was in 3 pieces:

1. Engine module
2. 50t Hydrogen tank
3. Docking Module with RCS 

So it could have been launched individually under a faring. The only structure that is really an issue is the spherical tank. A part of me do not believe that we would ever launch a tank like that.. that we would either build it to be inflatable or something and then launch it in space. Or construct it in a Low Orbit.

Any way - It got to space in one piece and all. That's all that matters. But I really hope there is still a future for the game were space stations with a VAB will be a thing. x)

You all read how the stack was launched during the testing phase in the R&D post. So I have put that step into the spoiler section bellow: 

Spoiler

 

Now after 'The Stack' had entered a stable LKO - it was the job for the Cruise Stage to rendezvous with it and dock to it. Because 'The Stack' was "behind" the Cruise Stage. The fastest way to ensure docking was to just allow it to catch up with the Cruise Stage.

In case you dont know - the lower orbit will eventually catch up with the higher orbit. Once 'The Stack' was directly below the Cruise Stage, I would lower the orbit for a rendezvous (being extra careful that I did not dip into to the atmosphere - I've done that before). I preferer to catch the target, rather than wait for it.. since when catching up you will raise your orbit when bellow the target. Thus minimizing the risk of accidentally planning a path that will deorbit you. See spoiler section bellow for procedure:

Spoiler

The ICV Hermes (CS) arriving at 'The Stack' burning to kill relative speed to it.

After a short while the Cruise Stage arrived at 'The Stack', and matched velocity. After that it was a simple matter of lining up the two parts and carefully dock them together. 

The ICV Hermes fully assembled and ready to blast off to Duna.

The whole sequence left the ICV Hermes with 46.52/50t hydrogen. And gave the vehicle 6.353Δv to launch the Ares Base 01 to Duna.

B. Transfer and Deployment of Ares Base 01 to Duna:

The ICV Hermes arriving at Duna.

Getting to Duna:

Getting the ICV to Duna was an easy task - It only required 1155 Δv and the burn "only" took 3m 24s burn (I tend to fly "underpowered" vehicles, so that's fast to me) - the nuclear engines really shine here. a slight correction burn had to be made to get a good angle on Duna to make the orbit circularize around a polar orbit.

Because of a Time Warp error - I accidently placed the time warp point too close to Duna's SOI. I have found that if you time warp through a SOI of another body.. it simply wont stop time warping.

Luckily enough I got a auto save going through the Duna SOI.. and because I still had a lot of Δv remaining, I decided to just do a very expensive burn to capture Duna. It meant a few expensive maneuvers, but I still only spend about half the Hydrogen load getting there. The orbit was set and it was time to deploy the base to the target area.

Main Lessons on deploying base to target zone:

Δv Margins on Capsules:

This turned out to be a much harder task than anticipated. a big Lessons Learned is to give the capsules more than 50-100 Δv to do the final course adjustments. Every orbit I came around I had to adjust the ICVs orbit to line up with an overflying of the target area, and I also had to lower the PE to 20-30km before launching the capsules. It meant a lot of maneuvers had to be done, and juggling the ICV in a low duna orbit (~50-60km) while controlling the capsules.

On the plus side - I did not have any issues with littering space, since the connecting parts would always be jettisoned in a degrading orbit.

Different Aerodynamics:

The capsules also had vastly different aerodynamic propperties. The LAB module for instance would keep accelerating until reaching the lower atmosphere - were the conical shape of the Living Quarter Capsule meant it were slowing down already in the upper atmosphere. the constant change in drag propperties - as well as the low Δv margins for each capsules, meant it was very hard to get a feel for where to aim, to hit the target area. 

Conclusion:

In the future I will have to devote at least 300 Δv to each capsule, and add more options to increase and "decrease" drag and burn the capsule - to better shorten or lengthen its suborbital trajectory - Probably by adding aerobreakes and RCS thrusters.

Deploying the LAB module:

Spoiler

The ICV in LDO - just separating the capsule module.

The ICV performing burn to enter a stable orbit.

Here from another angle. After looking at Kerbin so much - seeing vehicles over Duna is mesmerizing.

The ICV disappearing in the horizond while the capsule is continuing on its degrading orbit.

The capsule flying over the target area at high speeds.

the farings detaching.

I tried to drop the heatshield and faring at the same time. But the heatshield - having more drag - would smack back into the lab and destroy it... When deploying the faring alone and keeping the heatshield attached (to wait for the parachute to break the LAB module and propper separation to be possible) - the farings would not separate cleanly though. A lot have been said about farings in KSP2.. it is far from optimal thats for sure.

The chute has deployed and the heatshield dropped. The crate left to the heatshield is were Percy and the Duna Sample Retriever is located.

 

The puff engine breaks the fall

the parachute is blown off by the solid rockets. Its good that there is no collision from the cute.. I could see bad things happen here since it would most definitely get tangled with the LAB module.

Et voilà - landed safely on the ground.

Deploying Living Quarter:

Spoiler

Because of the improved drag on the Living Quarter Capsule it had to be deployed much closer to the poles. as you can probably see, This was the capsule with the highest drag.

flip and burn:

coming in over the landing zone. I found out in this stage that I had forgotten to add batteries to the module - meaning that I had to fly it down without SAS to have enough power to properly land it.. woopsie.

dropping the capsule - elements blowing clean off.

coming down.

The vehicle actually ran out of EC on the way down with the parachute.. but I made a little life hack. I made sure to have the fuel valves set to 100% and then turned off the engine.. You need EC to manipulate the fuel valves... but not turning engines on and off.. So I knew by doing this I could turn the engine on when close to the ground, and that would generate EC so I could steer the landing. - Cheat... yes.. effective? also yes.

deployed high.. landed quite a bit off. One of the 4 wheels was also destroyed when the farings deployed. Luckily it did not mean the mission was doomed.

safe on the ground.

Deploying Duna Rover 01 and 02:

Spoiler

Rover 01

With Duna Rover 01 I deployed it at a slight degrading orbit - to make sure the stack decoupler would not remain in space.

The Cruise Stage would then correct its orbit yet again.

Here from another angle - showing a huge crater I now want to visit at some point.

Now the rover capsule only had like 50Δv to deorbit itself - and like the LAB capsule it kept increasing in velocity. So it was looking like it would deploy far off target. I kept transfer fuel from the landing stage to break the vehicle further - thinking I would not need so much. I mean.. on Kerbin it had showed the engines were quite overpowered.

coming in over the target zone.

now falling short of the target. 

once the drogue chute fully deployed it was time to drop the capsule.

the rover were falling - with significantly low Δv margines.

I actually spend almost but all Δv before getting close enough to the ground.. only saving 1-2 Δv to detach the module.. I was actually sure that I would lose Rover 01 because it reached velocities up to 20 m/s falling the last bit.. But Kerbins sure makes their undercarriage strong.. I wanna know what those springs are made of since it survived that fall speed.

The rover survived the landing and the landing module blew clean off.

the rover was 32 km off target - but not broken.

 

Deploying Rover 2:

In a way it was quite lucky that I needed to make sure the stage seperation ring would deorbit - otherwise I would probably not have deployed rover 01 on a degrading path. It only barely made it down - but it did.. "luck in bad luck" as we say in danish.

On the second go I made sure to put it on a suborbital path from the start, meaning I could spend the Δv on aiming for the landing zone. It went a lot smoother.

see deployment in spoiler section:

Spoiler

Rover 02 safe on the ground.

 

Deploying Solar Panel Farm:

Spoiler

the solar panel farm was the last module to detach.

The ICV Hermes boosting itself back into a stable LDO for the last time.

stage separation and drop of the stack converter module.

The module had less drag than the rovers - which meant I deployed it too late. How ever I could use the RCS thrusters to shorten the coasting phase. I tried to force the drag chute to deploy in the hopes it would break the vehicle - it did not work as well as the RCS. 

I was worried to spend all the fuel though, since I didnt know if the two chutes would be enough to land the module.

 

The solar panel farm was completely unstearable - mostly because it has not RCW and low EC. So I could not use the RCS on it to break the fall - how ever I was lucky that it fell with 6 m/s under the two chutes.

It landed safe on the ground - which was lucky.. Since nothing would work without it. How ever It landed quite a bit off from the other base modules.

C. Assembling Ares Base 01

The marked circle is the spot were the base was setup after assembly. - The southernmost vehicle is the sample return vehicle and percy.

The base elements had landed quite far apart - and Because I had forgotten to put on batteries on the Living Quarters they were out of battery by the time they had landed. The only base element that could generate power was the Solar Panel Farm - and the only base element it could dock to was the LAB module.  So the base assembly was done in this order:

1.  Solar Panel Farm connecting to the LAB module
2. LAB module + Solar Panel Farm to the Living Quarter
3. The Ares Base 01 driving to suitable spot.
4. Rover01 driving to Ares Base 01
5. Rover02 driving to Ares Base 01

There is a "bug" were it seems that when you drive across the "tiles" of the terrain, the vehicle would "bump into" the next tile and veer of course and crash (if you didn't pay attention - it would happen about every 1km).

It meant that I couldn't just set it to drive on autopilot.. which meant that it took a few evenings after the kids were asleep to get it done. Dont worry I tried to make the tedium more exciting by doing it half attentive while listening to podcasts with my wife (a lot of quick saves and reverts).

In the end it a suitable place was found and the base was setup about 3km north of the crater the Duna Sample Retriever had landed.

Ares Base 01 setup and ready in the  'Claws of War valley'

The Rovers:

The rovers got back in good speed - they could drive 25m/s on flat terrain and they had enough RCWs to get back on track when they hit the tiles and veered off course. I drove with frequent quick saves - every bump survived was quick saved... since it was not a given that the vehicle wouldn't tumble.  

Rover 01 enroute to Ares Base 01

There was a bug, that was almost mission killing, that I also encountered on my Minmus mission. When I got within 2km of the Ares Base 01 it would just blow up. I am not sure what happens, but it would always be preceded by a "Ares Base 01 is on crashing course" promt. I think what happens is that when I drive with 25 m/s and get to the point were the base is loaded in - it loads in but the terrain shifts before its fully loaded in, which means that it will be catapulted off the terrain or just crashes into the terrain with the speed im driving.

Because if I reduced the speed to sub 10m/s - I would still get the prompt "Ares Base 01 is on crashing course" - but the base would not blow up.. and most parts can survive a 10m/s fall.

So both rovers had to slow down rapidly to close the final 2km - I didn't dare use Time Warp... since on Minmus my base would fall through the ground if I time warped with other structures/vehicles near it.

In the end it all panned out and the base was assembled and ready for the kerbals to arrive on the next Duna Transfer Window.

Ares Base 01 in the Claws of War Valley

<<<<<<<<<<Moving Forward>>>>>>>>>>

Next up is the arrival of the Duna Sample Return vehicle and completion of Challenge 6

Stay tuned in!

Edited June 5, 2024 by BechMeister

[BechMeister]

-=Duna Sample Return Mission=-
Part 2: Bring it Home!

The Sample Pod being launched into a LDO.

<<<<<FOREWORD>>>>>

Have I got an update for you. I finally got challenge 6 in the bag! But it was not easy, and before the end another mission killing thriller would present itself. I dont know if you, my dear reader, remember when I wrote this:

On 5/13/2024 at 10:11 PM, BechMeister said:

Sample Accent Stage:

1^st Stage -  48-7S "Spark" engine - 748 Δv
2^nd Stage - LV-1 "Aant" engine - 685Δv

Total: 1433 Δv

But as you can see, even though I've been looking at the Δv map a hundred times by now.. I failed to see that 1433 Δv is 12Δv shy of what is needed to get into a 60km Low Duna Orbit. I had my work cut out for me, and was really  working the problem.

Right as I was about to throw the towel in the ring and go redesign the Lander with the Sample Ascent Stage,  send it to Duna at the next Kermann Transfer Window... and extend the mission once more... I found a solution.. The most Kerbal of solutions.

More on that bellow!

<<<<<MISSION_TASKS>>>>>

 

A. Launching the Duna Sample Return Vehicle v2(DSRV) to Duna - Success

B. Launch the Duna Sample Pod(DSP) and dock with the DSRV - Success

C. Burn the DSP into a Kerbin transfer trajectory - Success

 

<<<<<Lessons Learned; Lessons Identified>>>>>

A: Launching the DSRV into LKO:

The SDG ready on the pad - a beautiful morning at KSC.

The redesign of the DSRV allowed it to be launched with the SDG - giving the glider one last mission before the end. The DSRV only weighing ~2t meant that the SDG had no issues getting the vehicle into LKO. The launch went without incidents.. or at least almost - the glider had a hard landing and toppled... Only taking minor damage - For details see spoiler section bellow:

Spoiler

SDG lifting off the pad with The Mun in the back - launching around 4 in the morning is my new favorite launch time. The way the game render the horizon and shadow of Kerbin is just beautiful.

Stage separation - as the dear reader knows, a routine operation by now.

The 1st stage lining up the pad.

and landed. Back in space the Glider is well under way to orbit:

The bright chrome may hit performance - but man the reflections look good.

DSRV successfully deployed in LKO

The SDG deorbiting.

Preparing to spiral down the heading alignment cone to runway01

lining up the runway -everything looks good.

Yet I end up scraping the paint and breaking a wing tip light... But worst of all.. ruining the nice well kept grass around the runway.

Well, minor damage all things considered.

The DSRV performing one of its many burns to escape Kerbin.

With the DSRV successfully launched into a ~80km LKO orbit. It was time to answer the interesting question of "how many passes around Kerbin will it take to reach escape velocity?" It turned out to be quite a lot - 25 to be exact.. and I was even lucky that the 25^th pass took me into The Muns SOI - thus providing me with a hefty gravity assist.

Unfortunately for me a bug showed up. Which meant that if I burned while in time warp, the AP would not be raised... So I had to do 25 burns averaging at 6 ingame minutes in real time... and due to my performance, every ingame second is taking 4 seconds. (I am never making a Ion driven craft again) Luckily I could put on a good podcast and get it done while doing the dishes. After every burn.

I recorded the raising of AP to just get a sense of how long it would take. I did the same for when I arrived at Duna, but in reverse - you can see the data below:

 

The DSRV was set to arrive at Duna on its second crossing of Duna's Orbit. Once outside Kerbin's SOI adjustments were made to the trajectory - picking a high intercept trajectory of ~ 26.842km as seen bellow:
 

Notice that the Duna capture burn took 1h 15min - because of the time warp bug I could not do this while in time warp... and I counted out every ingame second to be 4 sek. So I set a timer to 3h 30min and went with my kids to the playground. When I arrived home 4h later I had a PE of 60.210m - Perfect timing for circulating the orbit in a LDO.

See spoiler section for the maneuver nodes:

Spoiler

Notice the vehicle that has just left Kerbins SOI - that is the ICV Hermes coasting to Duna with Ares Base 01

The DSRV was now ready in an orbit that would pass over the Claws of War Valley twice a day - and it was just a matter of launching the Duna Sample Pod(DSP)

B: "KSC! We have a problem!":

 
Left: Percy - the Duna Rover01 - handing over the soil samples to the Duna Sample Pod (The Probe Core) Right: The DSP being launched.

 

As stated in the foreword... I had designed myself into a corner with this one. For two evenings I tried to find the most efficient way to get out of the atmosphere with the 1st stage. So the much weaker 2nd stage did not waste Δv holding velocity.

Work the problem:

Evaluating the different attempts could be divided into these 3 attempt categories:

Attempt 1:

1. Burn at 100% thrust
2. Stage separate 
3. realize Stage 2 is to weak to fight drag
4. failing to reach orbit.

Attempt one was pretty straight forward - it was before I had realized that I had screwed up the Δv requirements for getting into a Low Duna Orbit. I would burn the 1st stage 100% thrust and run out of fuel before I had gotten significantly out of the atmosphere. The rocket would get an AP of ~40-50km. But as soon as the thrust died the AP dropped drastically - lets face it.. the blunt face of the ascent stage is not really low drag... However thin the duna atmosphere is.

It resulted in the 2nd stage wasting much of its Δv just maintaining velocity, and slowly climbing out to were it was more efficient.. and in the end the rocket could not escape the atmosphere.

Attempt 2:

1. Burn at 25% thrust 
2. Stage separate much higher in the atmosphere
3. Be able to cross the Duna Kerman Line.

I remembered reading about ideal TWR - and manipulating the thrust handle, as to not overburn and waste Δv on fighting drag. I decided to sip the Δv on stage 1 like wine, instead of taking it like a shot, and try to extend the 1st stages burn time through the atmosphere so stage separation would happen in the thinner parts.

There is no reason to have an AP of 50km when your only 3-4km off the ground. It helped the rocket get into space - but it would still not get into orbit.

Attempt 2.5: not shown in the graph as its similar to attempt 3 but flown SW instead of E.

Now - as you can see Attempt 1 and 2 always started with a right hand turn - this was to match the orbit of the DSRV which was actually more close to south west than south - as shown. Meaning that the ascent stage had to actually fly directly into a polar orbit... and slightly against the planets rotation  - The lander module still had Δv left, and I figured I could turn the launch vehicle so it faced in the direction of the rendezvous vector. (before it was facing 90­° east).

I turned the lander and launched the rocket. Because there were less Δv spend on turning the rocket actually reached a PE of 12km - not enough, but we were getting close to going into orbit.

Attempt 3: 

1. Launch due east at 25% thrust
2. Stage separate and cross the Kerman Line.
3. Almost reach Orbit.

I went on a mad hunt on the internet for the most efficient ascent profile.. I found an old reddit post that mentioned that getting into a polar orbit required significantly more Δv than just going due east from the equator. (I really started to regret my polar adventure) It was something about being able to add the rotational velocity of the planet? - If some one can verify the information I would be grateful.

On Kerbin that is something like 200 m/s - not much but every bit counts. However.. going into orbital mode on Duna showed that, from where I was launching, it was only rotating with 20m/s... I tried to launch the rocket due east - which I figured would be the best option in relation to Coriolis effect etc? I may be wrong though.. there is no winning launching from a polar orbit it seems. Still I managed to raise my orbit to a PE of 17km - So very close to orbit! (it's still quite a few km off sure - but you dont need a lot of Δv to move the PE significantly at this point)

A screenshot of one of the better attempts at getting into orbit.

I am almost positive that had I had the missing 17 Δv (1433/1450 Δv necessary) I would have been able to make it into orbit.. but Alas.. I was short. After spending the evening on launching the rocket over and over and over again.. I went to bed defeated and exhausted... ready to throw the towel in the ring and waste another 2 ingame years before the Duna Kermann Transfer window would open and I could send a new Duna Ascent Vehicle. 

EUREKA !!!:

But text day I took one last look at the situation and I was thinking - "its a shame I can't transfer the left over Δv from the lander to the Ascent Stage..." When it dawned on me! The lander still had 135 Δv left. And when I turned the lander to avoid launching East and turn, to face South West and just launch. I had proved it had a TWR great enough to lift the Lander off the ground! 

It was time to lay a daring plan:

 

1. Burn the lander straight up as far as the Δv allowed and point South West into the orbital trajectory of the DSRV
2. Launch the Ascent Stage
3. Stage separate much higher
4. Just about reach orbit with 11 Δv left.

I would lift the entire lander as high into the atmosphere as possible, at the last moment I would pitch the lander back and launch the rocket! - after all I was only 33km from escaping Dunas atmosphere (50km altitude)... and launching from a higher altitude meant the 1st stage would have less of the thicker atmospheric layers to burn through.. and it would have a little bit of a speed advantage.

The result was this ( Note to myself - you should have speed up the footage):

 

It worked - I salvaged the situation and saved the mission.. in the most kerbin of ways I think... by launching my launch platform into space. In a way I am a bit sad the "cannon" launch was not with the awesome pitch mechanics I made.. but.. I solved the problem.. and KSP is all about problem solving... right?

for assorted images of the failed launch attempts see spoiler section bellow:
 

Spoiler

 

I think I'll go back and add the final Δv margins necessary for the Accent Vehicle to work as indented.  For future missions... on different low atmospheric bodies.

C: Bring it Home!

The DSRV picking up the DSP in Low Duna Orbit.

Rendezvous with DSRV:

Now that the DSP was in orbit, it was just a matter of rendezvousing. The DSP had 11 Δv left which was almost enough to complete the entire rendezvous and docking (which was good since the low thrust of the Ion Engines made fine maneuvering a bit hard.

Left: The DSP positions itself "under" the DSRV Right: The DSP uses the last Δv to rendezvous with the DSRV.

  
The DSRV matching the orbit of the DSP - Speed up 8.5 times. - notice how the m/s keeps jumping in values.

After a few maneuvers the two crafts were joined and the empty fuel tank + "Ant" engine, that had brought the sample pod into orbit, was dropped in a decaying orbit.  After which the DSRV boosted itself into its orbit. Finally carrying the valuable samples. 

Escaping Duna:

Once in orbit it was just a matter of doing the multiple passes of slowly raising the AP until the vehicle had escaped Dunas SOI. But before I could start... I had to raise the vehicles orbit so it was not overshadowed by the planet:

the orbit of the DSRV - notice how the trajectory from PE to AP passes through the shadow of Duna - that is the are where the escape burns has to be performed.

The point from were the craft had to do its burs to escape Duna, were unfortunately on the shadow side. After raising the AP of the orbit (so the entire orbit was in the sun), it would only take 7 passes to leave Duna. The 6th pass went through Ike's SOI (but not in a good way) and subsequently had to be an a lot longer burn, as Ike was changing the probes trajectory into the wrong direction. In the subsequent pass the vehicle left Duna and was ready for the final task - getting the sample to Kerbin.

 
A comprehensive list the DSRVs burns out of the Duna SOI - The list starts at negative numbers since burns were done from AP - which was raised to remain in the sun. Thus PE was placed lower than the starting point .

Returning the Duna Sample Pod to Kerbin:

The DSRV with the DSP mounted - making the finally maneuvers for a Kerbin Transfer. Notice Duna and Ike fading away in the background.

Once the vehicle was out of Duna's SOI I did a course correction to intercept Kerbin and stage separated the sample pod with heatshield module from the cruise stage. I decided - that since the cruise stage had 2.500 Δv left - that it was better repurpose the cruise stage as a CommNet satelite. 

I think I'll place it in Kerbins orbit but on the opposing side.. Just to extend Kerbins CommNet range.

The Duna Sample Pod with heatshield module decoupled from the DSRV. From now on it was just a "dumb" stage on collision course with Kerbin.

The sample would then reach Kerbin and re-enter the atmosphere (unfortunately on the night side) without any further incidents Challenge Completed!   - See spoiler section for re-entry and landing.

Spoiler

The Duna Sample Pod safely back on Kerbin with its valuable cargo - waiting for a pickup.

<<<<<Moving_Forward>>>>>

Now that I feel the hardest challenge had been completed. I expect the next step of the mission to be a walk in the park.

Next update will bring boots on the ground. The ICV Hermes is already enroute to K.G.02 for a refit and refueling.

See you in the next one!

 

 

 

 

Edited June 14, 2024 by BechMeister
reuploaded a image that were in the wrong aspect ratio

[BechMeister]

MISSION ON HALT
- Postponed indefinitely -

Foreword:

I have decided to post what I have done of progress on the challenges and postpone the mission... I have gotten a severe burnout from the game. As you can see I have acquired quite a few hours in the game - and I can feel with the absence of the community I just dont feel the same drive to press on through bad frame rates and bugs.

I am going to do a short write up of what has happened since the last post. And then we will have to see when I get back to it.

Challenge 7 progression:

First step was to get the ICV Cruise Stage back to Kerbin. The ICV was actually the first to leave Duna SOI - with the DSRV following shortly. Due to small variation in trajectory, the DSP actually managed to return to Kerbin first - and as of now - the ICV is still enroute to Kerbin approx 2-3 days from Kerbin SOI.

The maneuver that brings the ICV back to Kerbin.

As you can see the vehicle has spend a little more than half its hydrogen load - since The Base Stack is heavier than The Crew Module - I think it will have enough fuel to complete challenge 7 (brining kerbals to Duna and back.)

Getting the Crew assembly to orbit:

The Crew Module together with the two DAV vehicles were launched in 5 launchers. I reused the 2nd stage that sent the Duna Rover and Duna Sample Retriever capsules to Duna. 
For launch a petit four of the launches see spoiler section bellow:

Spoiler

 

 

 

 

 

 

 

It launched the 5 parts to K.G.02 for link up with the ICV. Hoping to have the module assembled by the time the ICV enters Kerbin SOI. 

 

for detailed maneuver walkthrough, see spoiler section bellow:

Spoiler

 

 

 

Arriving at K.G.02

2nd vehicle arriving at K.G.02 - an crew arm for the HAB module with artificial gravity. Notice one of the DAVs in the bottom left.

The modules actually arrived in very short succession - some getting there with less than 30 ingame minutes in between. I would park them all around K.G.02 (the space station) - and prepare for assembly.

The middle section was the last module to arrive at K.G.02

It was here I found out I didn't have RCS thrusters enough around the different modules, and the ones that had were poorly placed around their center of mass - meaning that assembly became rather tedious. I also had K.G.02 blow half up while assembling the module.. but I only found that out several steps ahead. The setback was what became the final nail in the coffin. 

I was almost done with the pain of assembling the crew module in sub 10 fps when I forgot to keep track of the Krakken.

 

Challenge 8 Progression:

The Duna plane attached to a pod containing a mobile fuel tank - to refuel the plane on the planet.

I successfully designed a plane that could take of from Runway 01  using the atomic engines. It had a stall speed of somewere between 30 and 40 m/s - which I learned from Herbal the space program is good margins for Duna Flight. 

On 6/6/2024 at 7:14 AM, herbal space program said:

On Kerbin it has a fully fueled takeoff speed of ~70m/s and a dry stall speed of  ~40 m/s, which are good benchmarks for flyability on Duna IMO. 

The plane was designed during the night (since there was only 3-4 days until the ICV would enter Kerbins SOI - the engineers on KSC were working full speed to maximise the time.) This means that I dont really have pictures of the building process.

I think i managed to design a plane that looked good while being able to get some flying done. But the plane has a limited Δv pool - so I am sending it to Duna with a fuel tank that has fuel for a few flights. 

I put it all in a pod and send it to orbit. How ever I made a small mistake when designing the pod. It had 2500 Δv - which I thought would be more than enough.. but I forgot that my 1st Stage only uses 1500 Δv - the rest is for boost back and landing. So the vehicle only had 500 Δv once in orbit.

Because the plane has so much drag I did not want to go through launching it again.. It was really difficult to get it to perform the gravitiy turn without flipping. So I made a slight redesign of my Heavy Tanker Vehicle - from the K.G.01 service vehicle pack. I gave it the micro port and now I can refuel the rocket and get it to Duna.For slide show of the launch of the HTV - see spoiler section bellow:

Spoiler

 

What is the current situation?

That means that right now the following is in motion:

1. The ICV Hermes Cruise Stage is enroute to Kerbin
2. The ICV Hermes Crew Module is being assembled at K.G.02
3. The Challenge 8 Duna Plane is in LKO awaiting refueling.
4. The HTV is in LKO waiting for a rendezvous with Challenge 8 Duna Plane.

Moving forward:

I dont know when I'll come back and finish this.. only time will tell.

Thanks for reading so far.

Edited June 20, 2024 by BechMeister

[BechMeister]

MISSION_RESUMED:
- Prepping for challenge 7 and 8 -

ISV Cruise Stage, slowing down to be captured by The Mun 

Foreword:

Alright - Now that I've had a good long vacation from the Game, I had finally recuperated the energy needed to grind through the assembly of the crew module and refueling of the cruise stage for the Duna Plane.  Of course with plenty of bugs to spare. The folder with images was getting pretty big.. So I thought it was time to make an update.

Mission Tasks:

A. Assemble the crew module and dock it to K.G.02 - Success

B. Refuel the cruise stage of the Duna Plane. - Success

C. Perform Capture Burn on the ICV cruise stage around The Mun. - Success

Lessons Learned; Lessons Identified:

A. Assembling the pieces:

The crew section docking with K.G.02 - awaiting crew and the cruise stage arrival.

The assembly of the crew module was a bit finicky. Not only was my pc running at 5-15 fps but when designing the individual pieces I forgot to give each piece its own balanced RCS thrusters. It meant some of the pieces were near impossible to adjust... But through a few evenings watching crime shows with my wife while RCS thrusting every once and a while, I managed to assemble the pieces and dock it to K.G.02 - now awaiting the crew to arrive.

Before sending the crew, I had to deorbit the transfer stages and splash them down on Kerbin.

The transfer stages has left The Mun SOI and are enroute to Kerbin - notice the Cruise Stage has entered Kerbin SOI. (right side)

De-orbiting the stages would proof if the aerobreaks would stabilize the vehicle enough to fly heatshield down through the atmosphere. A feat the grid fins had proved unable to. Luckily it worked.

With the aerobreaks deployed at 45° angle - the vehicle could maintain heatshield forward with a maximum deviation of 20° from prograde as seen here:

I was also lucky that the timing and spacing of all 5 transfer stages allowed me to land each of them without despawning any. I was prepared to do the quick save scam to land each piece.

The result was 5 successfully landed stages:

 

For a detailed walkthrough of a stage de-orbit: see spoiler section bellow:

Spoiler

The transfer stage decouple from the docking array

The stage de-orbits while the docking array burns up in the process.

The stage maintaining direction coming down.

unfortunately all the landings were happening on the night side of Kerbin, and thus you cant really see the landing after the plasma from re-entry disappears.

B. Refueling the Duna Plane:

The H.T.V. docked to the Duna Plane refueling its transfer stage with Methalox.

The refueling of the Duna Planes transfer stage went easily enough, albeit not without incidents. The refueling part went really smooth - I do know the characteristics of the H.T.V. a lot by now. It only took 3 launches to get it fueled up.

H.T.V. performing deorbit burn to land at KSC.

However, even though the refueling of the plane went smoothly. Landing the H.T.V. on the pad was obstructed by bugs. For some reason the landing legs and aerobreaks would bug out after a few loadings and reloadings. And since landing the 1st stage would always demand a load… or the disappearance of the orbit lines would demand a reboot of the game. The vehicle would “break” throughout the procedures. 

At least I tested a few times if I could deploy the landing legs, after I encountered the bug the first time.. 

H.T.V. reentering Kerbins Atmosphere.

Ofcourse I could just skip the landing of the 1st stage.. but I really enjoy doing that. Or I could push it to after the maneuver.. but that seemed like a lot of back and forth loading.

Its annoying because the landing would have been perfect! as seen here:

But the legs did not deploy, and the fact that the docking port is sticking out a bit, caused the vehicle to fall over on the pad. Maybe I’ll go about fixing the landing legs.. idk. I dont know if I will be playing KSP2 after this mission is done.

Long story short - the Duna Plane was refueled and is now ready to blast off to Duna at the next Kerman Duna transfer window.

See spoiler section for a complete rundown of a refueling mission - here the 3rd and last:

Spoiler

the lighting is off because there is an eclipse from the mun.

and splashdown - now with the engines ruined by corrosive sea water 

C. Catching The Mun:

The ICV cruise stage enroute to K.G.02

This went without incident. After a few expensive course corrections the stage was within the Muns SOI and had found a trajectory that would rendezvous with K.G.02 as seen on the screenshot above. Soon it will be at K.G.02, where it will refuel and fit the crew stage and it is ready to fly its crew to Duna.

Moving Forward:

Now the most tedious tasks are done. Ahead of me is the following tasks:

1. Get the crew from KSC to K.G.01
2. Transfer the crew from K.G.01 to K.G.02
3. Refuel the ICV Cruise Stage and dock it with the Crew Stage.
4. Fly the ICV Hermes and the Duna Plane to Duna.

Stay tuned for the next update until those tasks has been completed.
If people are interested I can also cover the Duna Plane in detail, if not.. It will be a surprise what's under the farings on the transfer module once it's re-entered Duna's atmosphere and it can be shed.

Until then, Stay tuned for the long awaited ending.

 

 

[BechMeister]

MISSION_UDATE:
The ICV Hermes (Cruise Stage) docked at K.G.02 - ready for assembly.

Foreword:

So I got the next step done, I had the ICV Hermes docked with K.G.02 - and the game did not crash like the last time I tried to dock an ICV to K.G.02

I flew the crew from KSC to K.G.02 - it became bit of a "victory lap" for the Kerbin Gate systems. Since I was able to use first the crew rotation plane, and the Mun to Low Kerbin Orbit (MLKO's) and this will be the first and last time I get a mission to and back from another celestial body.

Any way without further ado - here is the task list:

Mission Tasks:

 

A. Get the Duna Expedition Crew from KSC to K.G.01 - Success

B. Get the Duna Expedition Crew from K.G.01 to K.G.02 - Success

C. Assemble the ICV Hermes and prepare for the Manned Duna Mission - Success

 

Lessons Learned; Lessons Identified:

A. Single ticket to Kerbin Gate 01:

The Crew SSTO space plane docking with K.G.01 to transfer the Duna Expedition Crew.

 

This step succeeded - mostly. The few iterations I've made to the space plane over the time - adding reaction control wheels, more batteries etc. has meant that the Δv margin has become a little too small, and I spend a little too much Δv getting it into orbit - fortunately K.G.01 has plenty of Methalox, So I could refuel the ~300Δv required for an easy deorbit. 

 

If this mission wasn't the last thing I'll do in KSP2 I would probably go tweak the plane. But as of now its good enough.

 

 

The Duna Expedition Crew was successfully transfered to K.G.01 - At K.G.02 they will meet legendary expedition leader Jebidiah Kerbin - and proceed to Duna.

 

For detailed mission walkthrough see spoiler section bellow:

Spoiler

I think one of the things ill miss the most in KSP1 - is the procedural wings. You could really make some sleek designs.

Once in space the solar panels are out.

The crew is succesfully transfered.

the entire docking maneuver were done in a single orbit, and the space plane could perform its de-orbit burn right after separation with the station.

Reentry went smoothly.

It was clear though that I would not make it to KSC - So I aimed for the little island runway instead.

lining up the runway.

and landed.

B. Getting the crew to the ICV.

The M.L.K.O. docking with the H.T.D. 

 

The next step was pretty routine - the  MLKO's and H.T.D. (Heavy Tug Drone) are well tested. The step went without incident, and a detailed runthrough of the mission leg can be found in the spoiler section bellow:

 

Spoiler

The MLKO performing Mun transfer burn.

MLKO performing Mun Capture burn and rendezvous with K.G.02 - notice the ICV sticking out bellow the station.

Crew has been successfully transfered to the K.G.02

performing Mun escape burn. Once out the mun SOI - a few adjustment burns will be made and a rendezvous with K.G.01 setup.

Returning to K.G.01

MLKO and HTV separated to dock at their respective docking ports.

and docked.

C. Preparation for the Duna Expedition.

ICV - Hermes ready for launch of K.G.02 and to a Duna Intercept Course.

 

Finally, we came to the assembly of the ship that will bring the crew to Ares Base 01. After transfering crew, refueling the entire ship with monopropellant and methalox. It was time to undock the crew module and connect it with the cruise stage.

 

See spoiler section for ship assembly:

 

Spoiler

The inflatable heat shield had to be moved to the forward position again, now that the crew had docked with the vehicle.

 

Once the heat shield had been re docked to the front of the ship. It was time to undock the Cruise Stage and dock it to the crew stage.

 

 

 

and docked

 

Since the HAB module had to be docked in the "centrifugal gravity configuration", where all the crew seatings are positioned so the G-force from acceleration will be applied sideways rather than horizontal as positive G's  - I had to fold the arms down to "acceleration gravity configuration" : - See image below for clarification:

Left: Notice the HAB areas are configured in the centrifugal gravity configuration. Right: Notice the arms are being positioned for the acceleration gravity configuration.

 

The ship is now ready for the further mission - the final Δv count is 7.460. 

 

Moving Forward:

 

Next step is getting the Duna Expedition 01 to Ares Base 01 - as well as the Duna Jet.

Stay tuned for that!

 

 

 

 

[BechMeister]

MISSAN_UPDATE:
- Two step forward, One back -

Duna Expedition Team at Ares Base 01 Flagpole

Foreword:

My dear readers! This is going to be a long one.

Before talking about the triumphs and tragedies of this mission update. I would like to touch upon my two space stations K.G.01 and 02 - I build those back in the day to help me getting to the other bodies inside the Kerbol system. I hated getting things into orbit because of the wobbly rockets - and decided to build the stations so bigger crafts did not need to wobble through the atmosphere, but could launch from outside it.

Where as the game ended before I could fully exploit them... This mission update really proved the concept right! And even though its sad that this will be the last KSP2 blog I'll write.. (probably) It sure is nice that it brings all my projects together for one final Huzzah!.

Because I was genuinely enthusiastic about this one... the update has become very long. I apologize in advance and thank you, my reader,  sticking to the end and indulging me.

Enjoy!

Lessons Learned; Lessons Identified:

A. Get the ICV Hermes to Duna Low Orbit - Success

B. Get the Duna Jet to Duna Low Orbit - Success

C. Land the Duna Expedition Team in Claws of War valley - Success

D. Land the Duna Jet + Asset in Claws of War valley - Failure

Mission Tasks:

A: The Duna Transfer:

ICV Hermes enroute to Duna from K.G.02

The Δv Budget for the Duna Transfer and Capture:

The ICV Hermes had a lot of first for me. It was the first vehicle were I would attempt an Aerobrake and It was the first Intercelestial Vehicle to set out from Kerbin Gate 02 - orbiting The Mun. 

I was really excited to see what starting the journey to other planets from The Mun would do to the Δv budget.. and let me tell you.. I did not expect it to save me that much Δv.

Together with the Aerobraking it really made the journey cheap.

Δv cost pr. maneuver:

• Escape Mun and Kerbin SOI:..................................17Δv
• Duna Transfer Trajectory Adjustments:......................511Δv
• Duna Aerobrake Trajectory Adjustments:......................22Δv
• Duna Circularization Burn:..................................42Δv*
• Total:.....................................................592Δv

* Δv reading is after heatshield probe has been ditched

See transfer maneuvers in spoiler section bellow:

Spoiler

Maneuver 1: Leaving Mun SOI:

Maneuver II: Leaving Kerbin SOI - and adjusting for Duna Transfer.

The Journey from Kerbin to Duna:

Crew performing the reconfiguration of the HAB module for centrifugal gravity.

After the course had been charted to Duna, the craft had done its acceleration it was time to re-configure it for Cruise Mode and prepare for it to rotate to artificially generate gravity.

In my head cannon, the HAB module are build to be as light as possible, and there for needs to be under tensile stress. It also fits with the seating position, since it will allow for the crew to be exposed to positive G's only. - Once reconfigured it was just about rotating the craft until it showed 1G for the crew.

It looks a bit goofy perhaps - and I worry that this design would actually behave like this handle on the ISS - since the center of rotation is not at the center of mass. like this:

I imagine the vehicle wanting to flip like this would causing a lot of stress through the megastructure of the vehicle. Since the SAS would need to counter the urge to change axis. Perhaps some one more knowledgeable in this can enlighten me... if this would be an issue?

An way - It was the only feasible way for me to generate gravity, to keep the Kerbals healthy on the 272 day travel to Duna. I wish we had gotten the gravity ring module they were teasing.. But I guess there were a lot of wishes that were not fulfilled..

Aerobrake Maneuver:

The Duna Expedition Team preparing the ICV Hermes for the Aerobreak maneuver - notice the heatshields probe parked in front of the vehicle to allow the DAVs to move into position.

once the ship had been reconfigured for the maneuver. The crew safely strapped into the DAVs (Duna Ascent Vehicles) - in case the maneuver would cause a rapid unscheduled disassembly  - and the heatshield was deployed. 

See spoiler section for preparation for Aerobrake:

Spoiler

The two DAV's are repositioning for the aerobraking. They both need to be within the heatshields coverage. It also provides the crew with positive G's -albeit I don't think the breaking on the atmosphere would provide a lot of G's - but never the less. I find it quite neat.

The ship fully prepared - with Duna in the background.

After the ICV Hermes had completed the aerobrake maneuver - this was the message received from the ships crew.

"Once ready, I set our lowest approach to Duna, through the atmosphere, to a solid 24km - for some aggressive aerobraking... Go hard or go home I always say! I anticipated that I had to go low if I wanted an effect of the thin atmosphere - I was coming in fast after all. I was worried though.. I had read that the deployable heat shield create a significant amount of drag... So full SAS and RCS control was handled over to the ships main computer to keep the ship straight. And then it was just following the prograde through, while keeping a hand ready to pull the detach handle for the DAV in case Hermes wouldn't make it!"

- Jebediah Kerman - Duna Expedition Leader. 

See video below for full aerobrake maneuver - complete with the awesome Duna Reentry OST.

As you can see the vehicle performed admirable! One thing though... I was a little worried about the H² tank being graced by the plasma stream. I think it is an interesting design choice to make the biggest heat shield the diameter of the biggest fuel tank. With how the plasma plume will bend inwards I assume it will always be an issue? Maybe if you attach it directly to the fuel tank it wont.. but then you'll realistically only be able to use one... I think an more sensible solution would have it be slightly bigger than the diameter of the tank 

I did "paint" the fuel tank black - so let's just pretend it's coated in heat tiles. Boiling H² does not sound like something I recommend 

The result of the aggressive aerobrake was this capture:

Only thing left were slight adjustments to the orbit - costing a total of 42Δv to circularize the orbit around a pe70km - ap70km orbit and call it Objective Complete!

B - "KSC... We have a problem"

The Duna Jet performing its Duna Transfer burn from LKO.

The Duna Jet set out to its journey towards Duna with no issues. The issues would however arrive at Duna.

While the ship had plenty of  Δv to get to Duna... I did not have a lot of Δv to actually perform the capture burn.

The ship spend all but 58Δv capturing Duna - had i been less sloppy with were I entered the Duna SOI it may have been different.. but I was too focused on the ICV Hermes maneuver.. the Duna Jet became more of a secondary task for me.

the result was this:

The Duna Jet elliptical orbit after Duna Capture

But! with how succesful  ICV - Hermes  Aerobrake was, I decided to solve my Δv problem the same way. I lowered the AP by performing careful aerobrakes. I figured that If I went through the atmosphere with the Cruise Stage engine first - they would be able to take the heat and shield the main fuselage of the plane, as well as the atomic engine and the reentry engines of the capsule.  - also with the planes wings creating drag.. it would probably be the most stable way to go.

The Duna Jet performing aerobrake on the upper atmosphere - 43km of altitude.

Where ICV Hermes did an aggressive PE 25km aerobrake - the Duna Jet would initially just grace the atmosphere at 43km. 

Here is a diagram showing the lowering of the AP:

Notice that I had to burn prograde in the last pass to not go suborbital.

The circularization maneuver went perfect - and the last thing to do was to ditch the main engine - and raise the PE:
See spoiler section for more images of the leg:

Spoiler

The Duna Jet and Fuel tank separated in LDO (low duna orbit)  ready for reentry and landing in Claws of War Valley.

C. Boots on the ground!

ICV - Hermes above Duna after the heatshield has been ditched.

Now the easy part had been completed - now it was going to be easy... except it was here the game seriously bugged out.

I don't know what it is.. but I think the June 11 patch brought with it some really annoying bugs. I have never before had any issues with landing gears, grid fins or solar panels being blocked by nothing... or parachutes that would only be deployed if set to "immediately" - I guess Kerbol must have had some crazy solar activity.. for the DAVs were riddled broken systems.

I also had made a slight oversight with the DAV designs - the Δv available for deorbiting and landing was to low... Thus I had to perform deorbit burns with ICV Hermes, and then boost it into orbit again after releasing the DAVs. - luckily I had plenty of Δv available for unforeseen issues like these.

See spoiler section for de-orbit and re-orbit maneuvers:

Spoiler

The two DAVs successfully landed in the Claws of War valley - with all their "broken" pieces.

The two DAVs successfully touched down in the Claws of War Valley. - luckily the 4 engines sticking out the heatshield can be substituted for landinglegs AND they landed on leveled ground. Status after touch down:  DAV01  had 1/2 solar panels that worked... DAV02 had none as well as an ladder that would not extend.

I think the Kerbals can reach the capsule if they stand on top of a Duna Rover... I made sure to turn off all systems on DAV02, and just hope the batteries will last until the crew has to rendezvous with ICV Hermes - otherwise we have a rescue mission at hand.

The crew of DAV02 entering the Duna Rover01

After combating all the problems It was just a matter of carefully driving the crew back - The bug where bases and vehicles gets propelled when they load in is still present... (Percy was decentigrated by the bug) But by driving no faster than 10m/s I can quickly load into the DAVs and make sure they dont tumble over when they get loaded in. Luckily the base element and DAVs landed real close to each other - otherwise 10m/s would have been a pain... 

the distance between DAV01 and 02 (default name-26 and 25) to Duna Base 01 

For slide show of the entire mission leg, see spoiler section bellow:

Spoiler

Before any vehicle could be launched, the heatshield had to be ditched - having  now spend its uses.

The ICV -Hermes boosting itself into orbit again after putting the heatshield on a suborbital path.

ICV Hermes performing the deorbit maneuver before launching DAV01

ICV Hermes reorbiting itself.

DAV01 performing course corrections before ascending to the surface os Duna. 

Here we can see the crew of DAV01 on their way down to Claws of War valley.

 

DAV01 touch down. Now its time for DAV02

landing of DAV02 - now its time to pick up the crew.

DAV02 crew driving towards Ares Base 01 in Rover 02 - as you can see the roof of the rover extends up to the capsule.

Crew from DAV01 getting on Rover01 - leaning a bit precariously. 

The Duna Expedition Crew safely inside the Ares Base 01 

D: Two steps forward - One step back:

The Duna Jet on its way down - shortly before disaster would strike.

While the game had thrown bugs at me, and I had done a few design blunters - it was nothing compared to the issues the the Duna Jet would give me...

I had so many issues launching the thing - first it bugged in a way where it would be total vehicle loss once i used the decouplers. - I solved that by deleting the vehicle in orbit above Duna, loading a new one at KSC and using the cheat tool to get it into orbit again. (being carefull to match the orbit)

That made me successfully land the fuel tank for the plane... But then the solar panels would be blocked... I reloaded a safe.. and made sure the solar panels were extended in the VAB before cheating the vehicle back to LDO.. and successfully landed the fuel tank.

Then it was the planes turn... and it would not deploy the grid fins regularly. they kept going from being deployed to not be deployed from quickload to quickload.. Some times they would actuate.. some times they wouldn't...

I tried and tried to land the craft but in the end it didn't matter.. the for the plane was flawed...

 

I could not understand what was going on - so I put a copy of the plane on to the runway at KSC and launched it - and do you know what? It could not fly! 

I dont know whats going on.. It worked last I tested it. I dont remember if I build the plane before or after the June 11 patch though..?

Never the less. a double challenge completion is no longer possible - and I now have to design a new Duna Plane. Who knows.. maybe it will save the Expedition if(or knowing my luck - when) I find out the DAVs tumble or run out of battery.

For detailed walkthrough of the mission leg, see spoiler section bellow: It ends with a bang.

Spoiler

The fuel tank performing deorbit maneuver.

it was quite a long and extensive burn.

Aiming for the Claws of War valley.

The tanks decouples from the protective reentry capsule.

fuel tank landed.

Duna Jet performing deorbit burn.

since it was a plane - i went for a less aggressive re-entry. 

duna plane performing a left bank to shorten the glide.

Duna plane breaking aggressively before attempting the landing... which ended like this:

 

Moving Forward:

Next update will be the return tour of the Duna Expedition - provided nothing goes wrong - and a completion of challenge 7!

Stay Tuned in for More! 

[BechMeister]

-= R&D_Update =-
Challenge 7 - Making The Duna Plane.

The Duna Plane - DAP and its 1st stage enroute to space!

So - I have spend some time looking into making a new Duna plane - after the discovery that the plane I had sent to Duna was no longer air worthy.

It was interesting designing a increasingly lighter airframe with better stall speeds. For a long while I just kept improving the already existing airframe - But in the end I figured it was maybe an Idea to try make a dual engine design (just so I could get more Δv for actual flight.)

In the end it I remembered that by the time the plane would get to Duna, that the Ares Mission 1 crew would be home - So I might as well build an autonomous drone for flying around on Duna.

In the spoiler section bellow you'll find the development of the planes that were not chosen to be send to Duna.

Development "dead ends":

Spoiler

A. Re-balanced original Duna Plane.

So I found out - that what probably doomed the Duna Plane, was the fact that I had put air break's on it - as well as other little features that would make it worthy of the interplanetary travel - and that was too much mass to get it to fly. To save more weight, I started to reshape the plane to be as nimble as possible.

B. Making the plane lighter.

An obvious way to make the plane lighter, was to adopt a lighter cockpit - however it did also bring some issues, since the center of drag and center of mass was very closely aligned. I had to find a way to move the center of mass forward, without moving the center of drag backwards too much. The solution was model C.

C. Forward Swept wings:

This is by far the model that flies the best. The forward sweep of the wings moves center of mass forward, but keeps center of drag behind it. Its actually really fun to fly, and has a really low stall speed.. and can take off at 43 m/s. It almost turns on a dime.. I am considering making it into a methane air breathing air frame.

I felt I had reached the end of what was achievable with this air frame.. I would like to increase the Δv - and more fuel, would mean more weight, would mean to little thrust of a single engine design. Que design D:

D. Dual engines:

The dual engine design had a bigger wing area, and a even lower take off speed of 39.6 m/s - It was at this point I thought it was all well and good. With a take off speed on ~40m/s - I figured I could fill it with even more fuel, ditch the cockpit and make it autonomous. Which lead to the final design.

The new Duna Areal Probe (DAP):

Stats:

Weight Empty:....................:14,16t
Weight Fueled:...................:15,22t
Fuel Ammount:
- Hydrogen:......................:03,75t
- Monopropellant:................:00,80t
Δv Count on Duna:................:2034
Power Source:....................:KR4-P3

The plane is pretty cumbersome - It looks like something that should be super fast.. and it was not easy to get the plane balanced - a lot of weight was added to the nose via. the reactor and a few science modules to give it weight in the nose.. I always find it difficult to make probes balanced.. since the nose cones are so light - I know the game is dead.. but if we had a mass slider to the nose cones.. it would have been awesome. I usually just stuff it with batteries and monopropellant.

Take off:

 
 

Stall speed:

 

Turn Performance:

 

On KSC its only really possible to do rudder turns - pitch up and turn with the rudder and trade in the gained altitude for regained speed. That being said.. a turn should only really be performed with at least ~40-50 m/s - or the plane will not have enough airspeed to recover.. and the result will be this:

 

Developing a 1st stage:

Ever since as a kid, playing Ace Combat 3 - Electrosphere - I always liked the design of the Neocom R-352 and or the Orion 3 (with its 1st stage) from 2001: A Space Odyssey: 

The Neucom R-302 Orbiter and 1st stage. 

Concept of Orion3 with its 1st stage.

I wanted to do something similar - make an space plane, with a space plane 1st stage that can land itself again. It was challenging - as the game is really lacking sleek space planes parts in the sizes needed for making a propper 1st stage. My first attempt looked like this:

first flight test of the DAP 1st stage. v.1.0

This is the first iteration of the 1st stage. The two Skipper engines gave the vehicle ~3000  Δv - I expected it would be halved once it was married to the DAP - however another issue presented itself. The two skipper engines could not lift the vehicle from the ground at all. I could put on bigger engines - but the weight was an issue.. if the rear got much heavier it would not be able to reenter stable.

I ended up adding a LV-t45 swivel and two MK-55 Thuds:

1st stage v.3.0

The vehicle now had enough thrust to hover above the pad - I tried to add bigger engines, but it was impossible to balance the vehicle to not reenter with its rear first. I ended up adding 4 small "thumper" solid rocket motors to the stack. It meant the rocket had enough thrust to weight ratio to get off the ground - and the entire 1st stage with solid rocket motors were able to get the DAP (very gentle) up to 53km, before stage separation, with a AP at 90km and a gentle slope.

As you can see the rocket only endured 2.9g on the entire ascent  The 1st stage would then have to land on the other side of Kerbin - man I wish the game could have been developed to the point were we would have gotten multiple launch places... a runway and landing pads on the other side of the planet would have been so cool. 

After all the balancing, building and engineering had been done. It was time to certify the rocket and send it into orbit - first stop K.G.02 for a refuel before going to Duna in the next Duna Kerman transfer window.

 Challenge 7 - Here I come!

The DAP docked to K.G.02 - refueled and ready to launch for Duna.

The only thing left to do is the launch the DAP to K.G.02. Were it will dock, refuel and be on standby for the next Kerbin-Duna transfer window. The vehicle has enough fuel to get to Duna - where it will land and refuel at Ares Base 01 - for the Duna flight.

See the spoiler section bellow for a detailed look at the launch of the vehicle.

Spoiler

Because of the engine offset the vehicle will tip and "drop" 10° towards the side of the 1st stage. Which means it makes sense to launch the vehicle with the DAP facing west. Thus taking advantage of the drop, and use it to start the gravity turn.

However, The 1st stage uses RCS to orient itself in space (RCWs are just too heavy for this vehicle) and it has a really hard time performing a roll maneuver.

This means the rocket needs to perform a roll on the way up, to make sure the 1st stage is correct oriented for reentry - so the RCS only need to be used to maintain attitude. 

Engine cut, Stage separation and send off of the DAP - going into LKO.

The 1st stage can maintain an AoA of 20° on the way down. To make sure the rear does not flip forward it uses 8 aerobrakes as a control surface pushing the nose down. - Its quite a lot of aerobrakes - but alas.. we dont have propper body flaps - so I gotta make due.

And Landed - pretend there is another landing strip here, were the plane would be packed up and shipped back to KSC for refurbishment.

Back in space we follow the DAP performing its circulation burn - before going straight to K.G.02

DAP performing its break burn at K.G.02

Lining up the rear faced docking port. 

and docked with K.G.02

 

Moving Forward:

Next update will be with the Ares Crew going to the Duna Monument. I saw on a map that I am relatively close bye.

Stay tuned for more!

Edited October 6, 2024 by BechMeister

[BechMeister]

- Quick Update -

Hello all - I just wanted to say that I am still playing this mission. However I had a setback.. my gaming laptop's charger port got a lose connection, and for some reason it took the repair shop 3 weeks to diagnostic the computer and give me an offer.. (even if they advertised it would take at 3-5 days) - then it took 2 weeks to get the parts... At the same time I am doing my Bachelor in Graphic Storytelling. (I'm doing a comic) Aaaaand Christmas is fast approaching  as well..

On top of that I am a total masochist, and have decided to drive from Ares Base 01 to the site... which is going to take a while. Any way, rest assured that I am still going strong on this one. Here is a mood piece:

The Duna Rover01  enroute to the Duna Monument.