Free Trader Beowulf
-
Posts
96 -
Joined
-
Last visited
Content Type
Profiles
Forums
Developer Articles
KSP2 Release Notes
Bug Reports
Posts posted by Free Trader Beowulf
-
-
OK, so the next craft to land was the experimental Ion Speeder. A three man vehicle propelled by eight nuclear powered ion engines.
The design is intended to float above the flat plains of Minmus using its ion engines, with horizontal velocity provided by RCS thrusters or an advanced technique, I call "tilting over a bit."
But, it has enough delta V and sufficient thrust to deorbit and land, at least on Minmus.
Here we see it landed at one of the designated landing spots, you can see it's next to a KIS container that has a KIS resource pump.
The drilling rig can't refuel it, but I thought I'd put it on a designated landing spot anyway.
Back up on the Minmus transfer station, now renamed to S3 Strogoula Station, the crew of Jaegerin-33 had been waiting patiently for their turn, and finally the order to land came.
They carefully undocked and descended to the surface of Minmus.
On final approach, solar panels folded in case of problems.
And on the surface.
It was getting dark by the time they were down, but maybe you can see the drill station and refuelling points in the background.
Next time, the biome hopper and cargo head for the surface.
-
OK, so the next job was to get my base and drilling rig onto the ground. This proved to be much more difficult than I expected, as they were completely unbalanced. I usually use the RCS balancer mod to make sure my vessels are properly balanced, but these weren't. They had been in orbit of Minmus for some time, so there may have been some version upgrade problems, but I think it's more likely I just messed it up. Either way, it took several quick loads to get them on to the surface. I had to manually tune the maximum thrust of the engines to get them close to balanced, and even then MechJeb couldn't hit the planned landing zones. So the base and drill unit ended up several kilometers apart.
First, the base descended:
Then the drilling unit:
The plan was, to designate a series of landing pads near the drilling unit, supplied by KAS hoses from the drilling unit. To do that Bill set up a pair of KIS boxes south of the unit, attached to it with KIS resource transfer hoses, and with resource transfer units to refuel landers, etc.
That done, the crew drove to the base to check it out and take a well earned break.
Next time, the ion speeder and other craft descend to the surface.
-
Alright, so once they were on the surface, my Kerbals wasted no time in having a good night's sleep. The sun was setting as they landed, and nobody wants to explore strange alien worlds while over tired. But first thing in the morning they were up and at it on this strange new world. I'm sure they planted a flag, but I don't seem to have pictures of that.
One of Bill's first jobs was to survey landing sites for the various follow on craft. A relatively easy task on the pan flat surface of Minmus.
Then it was off to look for interesting surface stuff. Firstly, heading up the hill pictured below, dubbed the "Sugarloaf."
Then investigating all the various rocks that were to be found. The years of training and hard work had finally paid off for Wilfel, who was able to realise his childhood dream of examining rocks... in space!
Then back to the lander for a well earned supper.
Next time, the first of the base units descends to the surface.
-
On 8/24/2021 at 7:11 PM, Vanamonde said:
That first pic from Duna orbit is a nice bit of scenery.
Strangely enough, it's not Duna. There's a bug in my version that gives lights on ships infinite range sometimes. That's Kerbin illuminated by the red portside navigation light on my station. It is pretty though.
-
As I understand it an ejection angle of 160 degrees to prograde is the angle between your craft's position and the prograde vector of the planet you are orbiting, rather than your ship's prograde vector. So, for example, if it was 90 degrees to prograde, you would burn a quarter orbit before crossing the planet's prograde vector. Does that make sense?
Messing with the manoeuvre node until it works might be just as good though :-)
-
So finally Jaegerin-34 lifts off, heading for a Minmus landing by way of station S2.
Valentina, Ergan and Maulee lift off in Jaegerin-34, but the assigned crew for this mission is on board station S2 as part of the normal rotation. So they head for the S2 station where Bill, Jentrix and Wilfel swap with them.
That taken care of, Bill and his crew head for Minmus, where they proceed directly to land at the target location.
On the surface they meet up with their faithful pilotfish, the Minmus rover.
Next time we start surface exploration in earnest.
-
So, the next crew to launch is Bob, Verlian and Fredwig aboard Jaegerin-33, a direct ascent Mun lander (DAML).
The DAML was intended to be an improvement over the Apollo architecture. good as it was, Apollo left no useable infrastructure in place, so my DAML design is intended to leave as much useful hardware in space as possible. Here's a view of Jaegerin-33 once the upper stage of the Raven launch vehicle has been ditched. From left to right it consists for a Kerbin departure stage, a Mun/Minmus descent stage, an ascent stage and the command module.
Once the KDS is dropped, it can be refuelled and used as a space tug, in fact it's the JIPS model we saw at the end of my last post.
The descent stage has a hitchhiker module for long term surface stays, but once the ascent stage leaves, it has enough fuel to launch to orbit, where it can be used as an independent lander. In fact it's the Seagull lander we saw in part one.
The ascent stage isn't reused, but the ascent from the surface uses solid rocket boosters, the same solid rocket boosters that would be used as a launch escape system in the event of an emergency on launch, so the solid rocket fuel isn't wasted if there is no emergency.
Once a few DAMLS have visited the Mun and Minmus, no more will be required, just fuel supply runs, so crews heading for the surface of either body can use the cheaper Mun taxi vehicles.
Anyway, Jaegerin-33 launches and heads for mint satellite.
Originally, I had intended for Jaegerin-33 to land directly on Minmus, but then I realised that this crew was the same crew that did the first Mun landing, and I wanted to spread the honours around. So they were ordered to head for the Minmus transfer station to let the next crew lead the way to the surface of Minmus.
Meanwhile, the cargo lander intercepted the JIPS (Jaegerin Interim Propulsion Unit) space tug to pick up the docking port adapter.
Next time, we actually get some Kerbals to the surface of Minmus. Woop.
-
OK, time to actually land some hardware on Minmus, although just a scouting rover for now. My target zone is highlighted with the red circle on this map, a narrow band of the Great Flats lying on the equator. I wanted to aim for the Greater Flats, further east, as they have a much larger landable area on the equator, but the ore concentration there is quite low. So the Great Flats it is. I've also marked the locations of the two anomolies I've detected from orbit.
The Minmus cargo lander detached from the waystation and performed a textbook MechJeb landing on the Great Flats.
Once down, the rover scouted the local area, investigating local features of interest and assigning a landing spot for each planned payload to come. These are aligned in a north south line, where possible to prevent incoming landers from overflying other structures.
The lander, meanwhile, ascended back to its station on the Minmus Waystation.
One more vehicle needs to be mentioned at this point. The lander has a 1.25m docking port, and its next payload, a cargo barge, has a 2.5m docking port. Fortunately, one of my "space tugs" happens to be orbiting Minmus with the necessary adapter.
Next time, the first of the direct ascent landers heads for Minmus.
-
So, first launch is Jaegerin-32, carrying Asvan, Meg and Samwise Kerman, who will man the Minmus transfer station. Their ship is a Jaegerin class Crew Exploration Vehicle, model D (J-CEV-D), also known as the "Mun Taxi". The launch vehicle, a Raven D-1-200 single stage launcher, roughly based on the Jupiter DIRECT concept.
None of this crew have flown before, but they've been training hard so I expect nothing less than top performance from them.
One design innovation is the launch escape system, which consists of a set of solid rocket boosters mounted on a decoupler ring below the spacecraft. In the event of an emergency the rocket fire and the ring decouples, propelling the whole spacecraft away from the launch vehicle. However, if there is no emergency, the SRBs fire during circularisation, so the solid fuel does not go to waste. A small improvement over conventional escape towers.
The J-CEV-D "Mun Taxi" is a fairly conventional vehicle, a command module and service module with sufficient fuel for a round trip to the Mun or Minmus.
On the way to the transfer station, Jaegerin-32 had a couple of chores to complete. Seagull 1 and the Minmus rover had both been accidentally delivered without Mechjeb units, so the crew's engineer Meg Kerman will be called upon to upgrade both vehicles. First the Seagull 1 lander. Meg Kerman fitted the Mechjeb unit while Asvan familiarised himself with the controls of the Seagull and Samwise checked the lander was fully stocked with life support consumables.
Next up, docking at WS-Min-1 to upgrade the Minmus rover.
Finally, the crew proceed to the transfer station.
Here you can see the J-CEV-D docked in its final position on the end port of the station, which has ejected its Kerbin departure stage.
This zoomed in shot demonstrates one of the station's design features. The docking ports and solar panels are on the top and bottom surfaces, as seen in this view, allowing ladders to run the length of the station and to extend beyond the ends of the station to overlap with docked craft. This is to allow Kerbals crawl along the ladders and transport KIS containers to and from the station and docked vessels. Not a feature I actually used on this mission, but one that may be used in future missions. It does make docking with the lateral ports more difficult, however, as you have to be careful of overlapping the solar panels and damaging them.
Next time the cargo lander delivers the rover to the surface and we start scouting out landing sites.
-
Hi,
So I'm coming back to KSP after a long break, and the next thing on my plan was a major mission to Minmus. After almost eight years of game time I'm finally sending Kerbals to Minmus. I may be taking things a bit slowly.
Anyway, my Minmus mission has a number of objectives:
- Carry out the first Kerballed landing on Minmus
- Investigate the two anomalies that my survey satellites have picked up
- Establish a surface base on Minmus
- Test various low gravity hardware and techniques including ISRU systems and low gravity travel methods.
I'm using an older version of KSP (1.91) as I use a lot of mods and upgrades take me ages. Hopefully there's still some stuff of interest to people.
So let's look at the assets already in place, I've been preparing for this mission for a while and apart from the crew ships, most of the hardware is waiting to go.
First up is one of my Kerbin stations, S2 Snelsmore Wood Station, which isn't part of this mission, but my Minmus specialist is located on it, so I'm going to have to swap crews between the station and one of the Minmus lander ships. I assign all my scientists specialties and I try to send the appropriate scientist on a given mission. The S2 is based on the Mir from Eyes Turned Skywards. You can see a crew capsule, tug and supply vessel docked on the left side docking node.
Let's take a look at my first Kerbin station too, while we're at it. S1 Paekakariki Beach Station. It's based on SII's Shuttle Derived Station concept. It will play no part in this mission, but I include it for completeness.
Next is the Minmus Waystation, WS-Min-1 which serves as a staging point for hardware.
It has a number of important systems attached to it. There's the Minmus Hopper, a "biome hopper" style vehicle intended for surface exploration.
Then there's a cargo lander and rover. the rover will be used for landing site reconnaissance, and the lander will deliver the rover and other cargo to the surface.
The last systems docked to WS-Min-1 are a small propellant tanker and fuel "barge" which will be available to refuel any vehicles on demand.
The final station of note is the Minmus transfer station, current callsign Corvid-47, the callsign of the launch vehicle that delivered it. You can see from left to right it currently consists of the launch vehicle upper stage, two cargo "barges" (one with attached KIS fuel containers) and then the station proper. I won't be using this station very much, as my landers are direct ascent designs, but in future it will serve as a "gateway" style base for landers.
Another system for surface exploration is the ion speeder, not currently docked to the waystation. The speeder uses eight downward pointing nuclear powered ion drives to hover and fly in low gravity environments.
There is also Corvid-55, an upper stage used to ferry a pair of "tiny stack" landers to Minmus. The tiny stack systems are intended as rescue systems or orbital ferries, roughly based on the Lunar Escape System. They use external seats to minimise weight while still allowing a full three man crew to escape from the surface of Minmus in an emergency. We'll be testing one out during this mission.
Speaking of emergencies, I have an unmanned Mun lander standing by in Minmus orbit, the Seagull 1, in case there are problems and one of my crews genuinely does need rescuing. Yes, my Mun landers carry the "Seagull" callsign - "The Seagull has landed" - I'm sure you'll all agree that's hilarious.
Lastly there are two surface bases the IMSU (Interim Mining Surface Unit) and IMSB (Interim Minmus Surface Base). They are horizontal landers inspired by raptor9's warthog designs.
Next time, the first crew ascend to the Minmus transfer station and perform some important upgrades.
-
On 23 July 2016 at 7:12 PM, Tokamak said:
Well, that was easy. Thank you!
Also, nice obscure reference username
Thanks - I love it when people get it :-)
-
3 hours ago, Tokamak said:
I wonder if you could help me, as I'm having a bit of trouble. I'm currently trying to use the stock NTRs, as altered by this mod. They show up in the NF Reactors control panel, but attempting to activate them seems to have no effect. In their right-click menus, the statuses for energy and heat output are blank, as opposed to reading zero or any other number. Do you know what perhaps I should look for?
https://www.dropbox.com/s/pmp4dz1elnt7klu/output_log.txt?dl=0
https://www.dropbox.com/s/1zi52qv8hbpgaz2/persistent.sfs?dl=0
Oh, if it's helpful, the craft in question is "Kermes Drive Section"
I had the same problem - it's mentioned earlier in the thread.
The solution seems to be to activate the engines via staging before trying to activate the reactors via the right click menu.
-
My guess is, the pod below the chute may occlude some area of the chute, causing your drag to be overestimated (hence a higher terminal velocity than expected). Can you try to make the chute farther from the pod bottom (like pod-girder-chute) and does that make the number closer to your computation?
I did some more science and it looks like your guess is right.
I launched a 3 man pod with two radial parachutes and two girders sticking out on either side.
If the parachutes were on the ends of the girders, it fell at the predicted 7.7 m/s. In that position they were clear of each other and only partially overlapped the pod.
If they were on the pod terminal velocity was 9 m/s.
So the pod is occluding the parachutes, and they might be occluding each other.
So my calculation isn't too far wrong - I could even calculate the correct value for a simple pod under a single parachute, maybe, as I know the drag cubes for the pods.
But even without doing that, I know that I need to spread parachutes out, try to mount them where they won't be occluded by their payload and my predictions shouldn't be too far off.
Nice one, FancyMouse.
-
How do you get the data using the "drag cube"? Maybe take a look in the .cfg files of the parts. They have many different drag modifiers but I don't really know how to use them in calculations.
mk16 XL:
stowedDrag = 0.22
semiDeployedDrag = 1
fullyDeployedDrag = 500
...
name = ModuleDragModifier
dragCubeName = DEPLOYED
dragModifier = 25
The drag cube data is in physics.cfg - they look like this:
PART
{
url = Squad/Parts/Utility/parachuteMk16-XL/parachuteMk16-XL/parachuteLarge
DRAG_CUBE
{
cube = PACKED,
0.6278962,0.6383756,0.7139156,
0.6278962,0.6383814,0.7139156,
1.108058,0.7323978,0.6995487,
1.108058,0.9454046,0.1663975,
0.6278962,0.639505,0.7139157,
0.6278962,0.6373008,0.7139157,
0,0.2645478,0,
1.233453,0.6659461,1.233453
cube = SEMIDEPLOYED,
16.39305,0.5255063,1.822568,
16.39305,0.5255054,1.822568,
9.336478,0.1339835,18.06131,
9.336478,0.1646374,18.50363,
16.39305,0.5256646,1.822569,
16.39305,0.5253168,1.822569,
0,9.230829,-1.072884E-06,
3.459486,18.59851,3.459489
cube = DEPLOYED,
53.47527,18.69657,6.152891,
53.47527,18.69662,6.152891,
114.9405,12.06728,18.4375,
114.9405,11.60791,18.7325,
53.47527,18.71372,6.152892,
53.47527,18.67829,6.152892,
0,9.2347,-9.536743E-07,
12.15423,18.60625,12.15423
}
}
Buried in all that is the data I quoted. Piecing it together from previous discussions of aerodynamics, it seems the drag cube consists of six sets of three values, plus some other stuff. One set is for each face, with the three values being area, drag coefficient and "depth".
I just can't quite close the loop to turn that into an accurate prediction of terminal velocity.
It also seems that the drag cubes are generated automatically by KSP.
I think the values you've listed are left over from previous versions of KSP, certainly I used to use them and they used to work well, but I don't think they are current anymore.
-
Hi,
So, I'm trying to create a spreadsheet to calculate terminal velocity for pods and stuff coming in to land using just parachutes.
My calculations aren't working and I need some help from anyone who knows this stuff.
I'm starting with the drag equation:
F{D}=0.5 ÃÂ v^2 C A
Assuming drag equals the force from gravity and rearranging appropriately, I get:
V{term} = sqrt( 2 M g / ÃÂ C A)
where
V{term} is terminal velocity
M is vehicle mass in kg
g is local gravity
ÃÂ is local air density
C is surface area
A is drag coefficient
The drag of a given craft is potentially quite complex, given tip, surface and tail drag and small motions of the craft changing their relationship.
However, I'm only really interested in touchdown speed, with parachutes fully deployed. So I assume the only relevant drag is from the chutes and I further assume that it's all tip drag, in KSP terms.
So, to get that I've looked at the drag cubes for the parachutes and taken the fourth triplet, which is the drag data for the Y- axis.
My assumptions should mean any errors are in the direction that would make my calculations of terminal velocity too high, as I'm ignoring some sources of drag.
But I can live with that, I want to know if a given payload can be safely parachuted to the ground with a given set of parachutes.
So, I take a simple case, a Mk 1-2 pod is 4.12 tons, and a mk-16xl parachute is .3 tons. From the drag cube I get a fully deployed area of 114.9 m^2 and a drag coefficient of 11.6.
g is 9.81 m/s^2 and air density is 1.22 kg/m^3 I calculate:
V{term} = sqrt( 2 * 4.42 * 1000 * 9.81 / 1.22 * 114.9 * 11.6 )
V{term} = sqrt ( 86720.4 / 1626.0648 )
V{term} = sqrt ( 53.331453 )
V{term} = 7.303 m/s to three decimal places
However, when I actually launch a capsule like that on an SRB and let it parachute back down to Kerbin, the terminal velocity never drops below 8 m/s.
It never stabilises entirely, but it's in the region of 8.5 m/s. It's definitely higher than my prediction.
I've tried a couple of different tests and my calculations are never accurate. Oddly the mk1 pod I tested under a small parachute fell more slowly than I predicted, I guess its drag isn't negligible when compared to a small parachute.
but the Mk1-2 tests always touch down at a higher velocity than I predict.
Not a big deal on Kerbin, where I can test things, but a big problem for my Duna and Laythe missions, potentially. If I get an error of 1 or 2 m/s for Kerbin, I might get a much higher error for descents in Duna's thinner atmosphere.
So, er, anyone know what I've missed?
Thanks
-
That's one good looking ship - I'm definitely borrowing those drive pods when I get back to building airbreathers.
I don't know if it's modelled in KSP, I guess not, but closed wings like that also eliminate wing tip drag, which is non-trivial.
-
I've just been reminded I've been playing since 2012 and have never left Kerbin SOI
Thoroughness - I appreciate that.
-
I finally finished sending probes to orbit every moon and planet and measure everything's gravitational parameters. Only took me 1,988 hours.
Right, now to send some landers.
-
Very nice. I sometimes use 2m Kerbin Departure Stages for 1m probes.
To keep things looking good and aerodynamic I have to use radial engines for them, as the Poodle is too heavy and the 1m or 0.5m engines just look stupid.
But your 2m lander tank would be ideal for that.
Nice one.
-
Randazzo's heat management mod has a 3.75m mullioned heatsink for four standard LV-Ns too.
-
Just wanted to say that I too think Kosmos SSPP is a great mod, in fact one of my must haves.
It's just full of best in class parts - I'm thinking of obvious things like the RCS propulsion units and tanks and the Balka solar panels, but also easily overlooked gems like the LED lamps, which are perfect.
If it's not going forward, that's a real shame - but thank you CBBP for a great mod.
-
That's something I can certainly do. I'm writing it down.
:-)
Great work with the nuclear tanks - something like that should have been included in KSP 1.0, I guess. Although I'm not going to give SQUAD too hard a time given all the other cool toys they've sent us. But anyway - I really like the ones you've made, just the job for my surveyor fleet. Thanks!
-
In-progress screenshot below. I'm working on a set of Liquid Fuel tanks for use with the nuclear engines, now that they don't use Oxidizer.
Well that's fantastic news. Have you considered matching nosecones for the 1.25m ones - something the same shape as the Type B advanced nosecone would look great.
-
Likewise - I still get 0.24.2 when I redownload the Mac version from Steam
Project Minmus
in KSP1 Mission Reports
Posted · Edited by Free Trader Beowulf
Just a quick one today, I've not had much time for this recently.
So, back to Minmus orbit where the biome hopper was waiting to go the waystation.
A routine undocking and descent saw it land at one of the refuelling points on the surface.
The next scheduled load was a cargo lander and cargo barge. This was more complicated. In this shot you can see the Minmus transfer station, now renamed "S3 Strogoula Station." On the right hand side you can see two cargo barges, one has some buckboard cargo containers attached to it, one does not. Unfortunately the one I want is the one with the cargo containers that isn't on the end of the row where it can be easily removed. the other barge contains emergency supplies that I'm leaving in orbit for now.
In the background you can see the cargo lander attached to one of my JIPS orbital tugs.
First thing is to undock both barges and let them float free.
The cargo lander grabbed the cargo barge heading for the surface.
Then the tug grabbed the emergency supplies barge.
Finally a routine descent delivered the lander and barge to the surface. This image is pretty dark, but hopefully you can see the cargo stack, the biome hopper, the ion speeder and the J-DAML all at different refuelling spots next to the drilling platform.
Next time, refuelling and other surface shenanigans.