Caveman Challenge - Diamond

[Blaarkies]

This contains my entry for the Caveman Challenge 1.11 (its about completing the tech tree without upgrading buildings)

Below I will explain my missions and strategy to accomplish this. The "Diamond" level of the Caveman Challenge is just career mode with the following limitations

• No upgrading any buildings
• Custom difficulty
  • Every slider on the lowest/harshest setting
  • Except for science gains at 20%
  • Details can be found on the Caveman challenge topic
• You win when all Tier 5 tech tree nodes have been unlocked

That sounds simple enough, but so many advanced features are linked to building upgrades

• Kerbals cannot EVA in flight, no flags
• No fuel transfers
• No orbital trajectory predictions, or maneuver nodes
• Launch mass, height, and part count
• No quick saves/reverts

In short, if you think you got the hang of KSP by now because you have done Eve accent missions, or low dv transfers via slingshots, this challenge might put a bite back into the game!

I'll try to organize all the images in an imgur/google-drive album, with minimal pictures here to have an easier reading experience. Simply open up the album in a separate window to view the entirety of it.

Overall strategy goals (which inevitably fails, but it guides well enough)

• Get some surplus funds in the bank. Enough funds so that the next launch won't bankrupt you if when it fails
• Unlock all the science experiments. One thorough clean sweep over the KSC is easier than going back many times
  • This is not entirely possible though, since you need science to get science experiments
• Missions that cannot be 100% recovered, cost funds. Unless they are offset with contracts, or world first records
  • Hopping a Flea booster around the KSC is almost free
  • Dropped stages on the way to orbit are expensive
• Unlock the high ISP Terrier engine. This makes Mun/Minmus missions reliable and easy
• Post construction for Minmus biome hopping
  • Docking fuels pods in orbit.  Got a manned capsule with ~6000m/s dv. Interplanetary travel is still difficult, but it now has a big safety margin
  • (?) Stranded engineer in orbit . Rather put a scientist in EVA orbit, they can re-use heavy science pods (engineers aren't much more useful than dockings ports already are...for in this situation though)
  • (?) Docking boosters onto hanging rockets on the launch pad. Works wonders, less effort than 2x launches, and results in almost 3x payload to LKO (without needing more probe cores, so it becomes cheaper than 2x launches)
  • (?) An engineer with many assistants could build Spark-engine-boosters

Lessons learned

• Research tech nodes very carefully. Docking ports and Juno engine(with the basic aircraft wheels) were essential to my missions, but Rover wheels only got used once
  • Nodes with science parts obviously bring in more science
• Adding Thumper boosters to launch vehicles reduces cost per ton of payload, since you can double the payload, but don't have to double the controlling probe core
• Caveman comms can reach the Mun, so early probe landings are an easier way of getting science
  • Minmus comms might be possible after many satellite contracts
• Docking without RCS is obviously harder, but don't overcomplicate it with weird designs
• Kerbals can EVA infinitely by moving their EVA pack into/out of containers

 

The Start
Album 1

The settings:

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So we start out with zero funds, zero science, and zero negative 1000 reputation 
That's fine, well make money after the first launch, unless we can't launch without any funds!  What we do is...roll the dice. If you are lucky, you will get 2 contracts which give 600+ funds in advance. We then use that to launch the first business vehicle (getting funds is the top priority now, science we will only be taken if its free)
Be extremely careful when clicking to accept contracts:

• Miss-clicking the red decline button will cost you probably all the funds you have (some have a penalties of like -90 000)
• Accepting a contract that you are not ready to complete yet, can become a heavy ball-and-chain on your space program 
  • Some contracts cannot even be declined
  • Declining contracts are expensive
  • 1 less slot for active contracts in flight make it difficult to be profitable in launches

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Lucky enough with those funds, I "launched" this...thing. There was hope that pressing spacebar with that empty booster would count towards the "launch first vessel" contract (spoiler, it doesn't)

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Now take crew reports, EVA the kerbal since we are landed and take EVA reports as well. Shove those EVA reports into the capsule to take new reports. An easy EVA report here, is to climb on top of the capsule and jump off! When in mid air, click the "EVA Report" button. 
After that, run up to the Crawlerway towards the KSC buildings. The Crawlerway gives another EVA report.

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Run back to the capsule, drop the EVA report, and run down to the beach. There's more EVA reports there, as well as some "World First Contracts" on the way (thanks to one of the masters of this challenge for pointing out that trick)

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This nets a total of...a puny amount of science. Need a tiny bit more for the first tech node.

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Make a simple hopper rocket on the runway, launch it towards the KSC and collect the science.
Do not use decouplers on the Flea booster...rather land it together with the capsule to get the recovery funds back.
Remember to make a habit of removing the Kerbal inventory items, and also any ablator in the heatshields (if you are carrying those).

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Once we have 5 science, we unlock the tech node with the thermometer science part. Getting new science opportunities is very important here, but science itself takes 2nd priority (it will make sense in a minute).

 

Dropping spent contracts
Album 2

I'm still stuck with that "Escape atmosphere" contract, taking up a valuable slot of the total 2 slots we have for contracts.
To cash in on it, we launch...a thing! Its simple really, get the capsule up to +70km, but also safely back down, or risk having 1 kerbal less. It is tempting to do this before unlocking decouplers, but its not worth the risk. Even a Flea booster on the back of a capsule can be enough to flip it, into a really aerodynamically stable orientation. Those dart too quickly into the ground for parachutes to even open up.
So add a decoupler between the capsule and the Flea (but point the decoupler downwards to save some recovery cost).
The Hammer booster can be hot-staged: no decoupler used, just fire up the Flea right before the Hammer is empty (when it has about 1 second of fuel left, or 100m/s dv in the readings). It is important to catch this earlier rather than later (a late burn will cause the Hammer to not explode off the craft as soon as it should, while blocking the Flea's thrust)

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Get some science on the way up. In this launch science experiments can be done when Landed, and in low atmosphere (-30km?), and in high atmosphere (-70km), and again in space. You will have to choose which ones you want, since you can't carry them all without more science containers.

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The landing happened in the mountains (yeah fresh science! but, dangerous steep slopes)

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I couldn't get the capsule to stay put without SAS on (in order to EVA the Kerbal). So i decided to not risk getting outside for a tumble

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The craft name in the mission debriefing explained the entire purpose of this launch.
This got lots of useful science, and even some funds, but the best part is it opened up the extra contract slot!

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Eternal balance, science vs funds
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What follows is a bit of a grind to get enough funds for bigger missions. If done thoughtfully, you can also get science along the way. Go get some contracts that specialize in simple tests:

• Test on launch pad
• Test parachutes at less than 10km (just check that the speed range is attainable)
• Haul parts up to altitude

Anything that you can do while hopping around the KSC will fit. Then just aim for a different KSC buildings each time

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Its not a ton of science, but it adds up soon enough

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Orbit Kerbin
Album 4

We got a contract and word first records to fund this mission - getting into Kerbin orbit. Building under the strict limitations, I found an interesting bit of info: The Reliant engine is better than the Swivel engine under some circumstances. That sounds plausible, but here I found that even when the vast majority of engine usage happens in a vacuum, the Reliant (with a worse vacuum Isp) still beats the Swivel in terms of dv (and of course thrust as well). This is due to the Reliant having less mass than the Swivel. It misses out on gimbaling though, but that's not necessary for this craft being well balanced and in space most of the time.
This effect is very apparent when comparing a Terrier engine to a Spark engine, on a single 2t fuel tank. They almost break even at that mass (depending on the payload of course), but unless lots of thrust is needed, you are better off with the Spark since it has less mass for the previous stages to push around.

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Pretty typical launch. This shape is very aerodynamic, so get that trajectory flat quite early. A trick I use to know if my launch is going well:

• Open up that orbit info tab (purple button, bottom left corner of the screen)
• Keep the Apoapsis minus current altitude to less than 10km
  • apoapsis= ~37km,  altitude= ~30km, 
  • apoapsis - altitude = ~7km, (which is less than 10km)
  • This works well for the part of the launch where your speed is between 500m/s - 2000m/s
    • At the launch pad, the results of this is obviously bogus 
    • Near final orbit, its not that useful anymore
  • So when that difference gets greater that 10km, i ease up on the throttle. Below 10km, and i throttle up a bit
  • This is probably TWR dependent, so make that "10km" threshold whatever works best

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Got into a safe (but ugly) orbit, its fine, its +90% successful if  you could measure that. What now? Don't deorbit yet, listen to the music and stuff, but more importantly press escape, go to the contracts building. Check if they have a new contract, like "Return to Kerbin from orbit". Its free money! 

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We have been using fuel very sparingly and efficiently up until now (either it costs funds, or we need it to make orbit, always an excuse). Now, that fuel is going to be crashing into Kerbin, might as well use it while you got it. Use as much as you need for a reentry close to the KSC

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Caveman diamond rules set the reentry heat to 120%. I have never tried that before, this was my first time. I was afraid Jeb couldn't take the heat, so I packed a heatshield (empty out that ablator though, its just extra mass). After this reentry, I know its not that harsh at all. Gentle reentries could survive without one I think.

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Got near perfect reentry profile that landed me just beyond the tip of the runway. Also congratulations Jeb on that promotion!

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Challenge the Mun
Album 5

At this point, I wanted to do that Mun contract, but didn't have the Terrier engine. Without it, even a stripped down command pod vessel could barely reach the Mun. I tried to attain the extra science needed with the famous KSC roller! It failed miserably, the Materials bay I added in the center exploded after exceeding 6m/s. So i added sturdy...wheels?. That wasn't controllable at all.

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I did some more KSC hops, maybe I could source the little bit of science needed locally. That didn't seem like the easier way

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I knew that if i could just do 1 Mun flyby, I would get loads of science and cash. Im going to say Jeb convinced me to do it, and that it was out of my hands, but we are launching for a Mun flyby!
We are using a similar design as the first orbit vessel (didn't get enough science for new parts, so it feels a bit like the middle ages over here). Same trick as before, the Reliant engine actually performs slightly better as a vacuum engine here. 

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Get into a nice orbit. To intercept the Mun:

• Draw a vertical line through Kerbin
• Measure the angle from the top, clockwise towards the Mun
• If that angle is 45°, its time to do that trans-munar injection burn
• When your craft is at the bottom of that vertical line, just burn prograde
• When your Apoapsis touches the Mun's orbital line, stop burning

I think 55° is slightly better, but its hard enough measuring this by eye so we all just say 45.
In hindsight, don't set the trajectory beyond the Mun, rather let it barely touch the Mun's SOI to be safe.

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Running on fumes! Good thing the calculations were correct, there is still fuel left. If all goes well, it will be enough fuel to get back to Kerbin.

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Got a dangerous intercept here. Try burning towards the "other" radial () marker, that should push our orbit so that we don't get a slingshot into interplanetary space.

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That Earth Kerbin-rise never gets old 

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"If all goes well"...I jinxed it by saying  This could be really bad, we don't have enough fuel to change much about the orbit, we don't have fancy upgrades that show us predictions about encounters...Jeb's fate is pretty much locked into whatever the Mun wants to do with this now.

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After lots and lots of slingshots, the Mun finally messed up while toying with Jeb. This ended up on a trajectory somewhat past Minmus, we have a chance to hit the atmosphere with this tiny bit of fuel! 

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At Apoapsis, check the orbit velocity and compare that to the total dv in the craft. If you can cancel most of that orbital velocity, you will be falling almost straight down to Kerbin, hopefully drowning some of that excess kinetic energy into Kerbin's atmosphere.

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Remember to drop the bottom half of the craft earlier rather than later, tumbling head first is something i have not tested yet.

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Landed at a pretty crater

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Enough science for the all important Terrier engine, this was quite stressful

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...
More to come!

 

Edited February 21, 2021 by Blaarkies

[paul_c]

Brilliant!

May I ask, what is the dV (say, in a vacuum) of the craft that got you to the Mun and back with a science jr and command capsule on it? I am short of fuel, as usual, trying to do the same!

Edited February 3, 2021 by paul_c

[James Kerman]

Thread moved from Challenges and Mission Ideas.

[Blaarkies]

14 hours ago, paul_c said:

Brilliant!

May I ask, what is the dV (say, in a vacuum) of the craft that got you to the Mun and back with a science jr and command capsule on it? I am short of fuel, as usual, trying to do the same!

The simplest one used in "Challenge the Mun", called "To the Mun too" (vehicle name shows up in the end mission debrief report). The dv left in orbit, i don't remember, but maybe that's visible in one of the screenshots.

• 4219m/s dv, vacuum, total (Those 2 Fleas on the decoupler messes with KSPs calculator a bit, so dv might be ~100m/s less)
• 1.26-1.56 TWR (At sea level, and at vacuum which that first engine never reaches)
• Design
  • Capsule
  • 3x FL-T200 tanks
  • Reliant
  • 6x FL-T200 tanks
  • Swivel + 2x Flea (on a round decoupler)

 

The second one from "Orbit the Mun", called "To the Mun tree"

• 5170m/s dv, vacuum, total (Same possible error calculation because of the Fleas)
• 1.08-1.39 TWR
• Design
  • Capsule
  • Materials bay
  • 1x FL-T400 tanks
  • 1x FL-T200 tanks
  • Terrier
  • 4x FL-T200 tanks
  • Swivel + 2x Flea (on a round decoupler)

 

I hope these ideas inspire success in your own run...and watch out for that Mun slingshot! 

[paul_c]

Thanks, I need to have a re-think of my rocket design and try something different! Can't afford to trash too many in the process.....

[Blaarkies]

This topic is image-heavy, therefor it is split up into more manageable sections to page through.

 Orbit the Mun
Album 6

So i found this contract to orbit the Mun. Perfect timing, Jeb still has a bit of PTSD from the previous Mun mission, but this time he had way Terrier dv to play around with.

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Same vessel as before, with heavy modifications to optimize for the new Terrier engine. Launch profile is pretty clear in the album, it was a neat launch.

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Get into orbit, do the same trick as before to touch the Mun's gravity well

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Proof that i learned nothing, or am I cursed? Doesn't matter, we have enough dv to fix it this time. Besides, to get into orbit of the Mun (for the contract) we have to undo that hyperbolic trajectory anyways.

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Finally got a less terrifying view of the Mun this time

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At Periapsis, slowdown into orbit. How much to slowdown? (you want to save all the fuel you can)

• The mathematician says, go use those gravity parameters in the Mun's knowledge base (popup window, right hand side), use the Vis viva equation and tada!
• The engineer says, just check the SOI number, and make your AP number less  than that
• The lazy bum says...just burn until the orbit contract is complete ? 

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Nice orbit, collect all the science there (use the Science pod to stash more science, to open up the temp/baro experiments for new science)

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We want to get back to Kerbin. We can save lots of fuel by use this elliptical orbit to the best of its abilities. Jeb is orbiting clockwise (wrong way around). Buring at PE will change that orbit to look like the next picture (a hyperbolic trajectory). With that in mind, just time this burn so that the bottom exit line is parallel with the Mun's orbit at the time of exit. Burn about 100m/s to put yourself into an elliptical Kerbin orbit
That number could change depending on your exact orbit. Add/remove some if you feel the need

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This ends up getting us comfortably close to the atmosphere. Take that mean Mun! If Kerbin orbit is "halfway to anywhere", the this elliptical orbit must be "most of the way to anywhere". I decided to get some Kerbol science while im at it, just burn a little bit at Kerbin PE, get that AP to somewhere +84 000km (Kerbin SOI).

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Important, do not be hasty with this one. The Oberth effect can strand you around Kerbol pretty easily

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The moment you hit Kerbol space, the first thing to do is to stop panicking. Jeb will be safe, but every second you waste is another second Jeb has to wait. Do all the science while you are there. To get back, follow these rules:

• Ignore the orbit markers this time
  • You and Kerbin are basically at a close rendezvoused relative to Kerbol, the parent body is so far away that that you don't really need to consider it (just lock docking in high Kerbin orbit)
• We are assuming Jeb exited Kerbin's SOI at ~30m/s. If you were hasty, this can easily be over a hundred
• Find Kerbin in flight view, in the starry "sky". You can't miss it (it's an entire planet afterall. You might be on the dark side, so just check around for the Mun
• Aim the craft directly at Kerbin. You have no pink target markers on the navbal (no fancy buildings, remember), so you have to do this by eye
• Note your total dv at the moment. Burn about 100m/s
  • Use more if you were the hasty type of player
  • Using too much could put you on a bad trajectory
• Wait. This is a scary wait, because you have no reference about whether this was correct, but it should only take as long, as you have been outside the SOI

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"Outside"

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Coming back

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Once one the way back, just fix that Kerbin PE into the atmosphere. Radial markers ( / ) are your friends here, since you want to change direction, not energy. 30km PE has been safe for my empty heatshields.

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Burn any leftover fuel as soon as you are at the atmosphere (not going to do anything else with it afterall)

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Keep landing at that crater, or do i have my images mixed up ?

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Some sweet science for another tech node!

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Shenanigans I
Album 7

This awesome contract popped up, wheels! I forget to stay on the look out for parts I don't own yet, I could really get an advantage using this. With the previous science bundle, I upgraded the Materials Bay tech node, so with wheels I could easily farm the entire KSC in one clean sweep.

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When working with wheels, the gizmo modes are a great help. Press "F" to switch to "absolute" mode, and just pull on the rotation gizmo until it clicks once (it will snap to the nearest perfect rotation). This will rotate that wheel to be perfectly vertical, pointing perfectly forward as well. The translation/move gizmo can be used to move wheels inline and match height as well.
Holding down shift, you can move them beyond their local area (and eyeball whether they match in height/alignment with other parts)

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Drive to every building on the KSC, its probably a separate biome. Its weird what counts as being in the biome, but mostly just try and bump into the structure. For example, getting the flag pole biome, I had to reverse into it. Maybe its about touching, maybe its about the distance to the science part?

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By the time I was done with this, I wanted my contract slot back...but I also liked having those wheels. So I decided to have both!
I parked 2 many wheeled versions of this craft on the grounds, and if I need wheels again I could just engineer them back onto the new craft

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With some surplus funds, I decided to pickup the last bit of Kerbin space science (mostly the Materials bay science)

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This topic is image-heavy, therefor it is split up into more manageable sections to page through.

 

Change of plans
Album 8

 

A next level contract appeared, "Land on the Mun". Somehow I knew this is the one I needed to pick, there was even a contract for "Science from the Mun". This will put the program on track to unlock some important tech.

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Only after I started seriously building the Mun landing craft, it became apparent that my space program was not ready for this yet. A completely stripped down command capsule did not have enough dv for a landing and return (at least, not with my skill). A probe core could do it, but I have no reaction wheels (so all space rotations need to be done with engine gimballing), and I had no comm network at all. These contracts really didn't seem possible at the moment.
Previously I made a craft reach Kerbol space, and also orbit the Mun. That definitely has enough dv to reach Minmus orbit, as long as I'm careful. So I used the long range craft with just enough science "pods" for high, and low orbit.

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Same thing as going to the Mun. Draw that vertical line, measure Minmus being about 80° clockwise from the top of that line, and burn at PE to move your AP up to Minmus

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I used to only launch at the AN/DN inclination nodes, but since they are invisible now (and a friendly Caveman convinced me about how little dv it take to correct that), I decided to just launch whenever. don't worry about it too much. You orbit will probably not match up with that of Minmus in full 3D

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Wait until you are just past the Mun's orbit (that puts you about 1/3 of the way from Kerbin's gravity well). Out here, just burn anti-normal (), or "south" (eyeball this in flight mode, or learn to read the navball: 180° heading, on the line between blue/brown should put you there).
You might have to reverse these directions based on the specifics of your orbit

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At this point, I felt that I might be overshooting. Minmus would go flying past right below Jeb! To fix that, burn radial-in () to decrease the AP and also increase horizontal speed that keeps you up high for a bit longer.

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Waiting for that intercept is torture, I'm never certain if it will actually hit the Minmus SOI. It finally did, but the resulting intercept was disgusting. To fix it, I just burned retro-grade ( ) . Apparently it's no more expensive than doing radial burns and then getting some Oberth at PE. Who knew (another member on the Caveman thread, really they knew )

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Jeb finally got to see the glistening minty surface down there, but we are only doing orbits this time (i didn't pack enough science pods for more, I would rather save time and do landings later)

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We are in an elliptical orbit now. This sounds familiar...like something we did around the Mun earlier?

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Wait for the moment where the exit line would be parallel to Minmus' orbital line (also, i'm orbiting clockwise again, the wrong way around isn't that bad if you only orbit though).
At the right moment, I burned about 50m/s dv to get out of there
This was not enough. It depends on the orbit, but I would rather pick +70m/s

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A very hot reentry. It seems these heatshields can really take a lot of punishment.

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Got lots of science for this little mission, it was definitely worth it.

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Checking out the tech tree, I stopped to think about the Spark engine parts. 4 assisting Kerbals could help built tiny boosters around an existing craft on the launchpad. But the docking port allows me to add fuel pods to craft in orbit, which would greatly increase their range.

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[paul_c]

Cool update. 

I think we're going down the same route - using docking ports to add extra fuel to a mission - it will be interesting to see how you progress on this and how the landings go! You did well to intercept Minmus!!!

[Blaarkies]

Docking blind to land on the Mun
Album 9

I still had 2 locked contracts requiring me to land on the Mun and return to Kerbin. With the docking ports unlocked, I figured I could add fuel pods to the final craft to give it the necessary dv. Here is the probe controlled rocket bringing 2 small tanks of fuel op to orbit.

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A great way to improve stability is to use the "Flow Priority" setting. On each tank, you can set the order in which they should be drained. Here I have all the bottom tanks drain first, leaving me with a top-heavy rocket before we go supersonic.

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Very typical launch profile, just remember to pop out that antenna as soon as you are in space. At this point, i don't have many comm sats up there so I still lose connection often, but the antenna already helps a bit.

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Next up is the Mun landing craft itself. This is a stripped down version of the previous rocket, it has less science parts on it.

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Wait on the launch pad until the fuel craft is right over the ocean to the west of the KSC continent, or at the edge of the desert.

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A typical launch, try and match your AP with that of the fuel craft.

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Double click on the purple square ship marker as soon as you can. The distance info will make this much easier

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Get into orbit before worrying about rendezvous. These are the things we need to worry about:

1. Inclination. Make sure we orbit in the same plane as the other craft. Plane changes are generally cheaper when they are further away from the planet.
2. Intersect the other orbit. We need to make these lines touch if we ever want to dock. Its best to make this intersection in the first daylight part of the orbit, as to give yourself more time in good lighting to figure out the docking.
3. The intersection should be parallel and thus only touching at one point.

With those 3 requirements achieved, it become very easy and efficient to finish the rendezvous. Lets look at inclination, this image shows how bad the inclination difference is, and it also shows that we are higher (due north) than the other craft (at least for comparing this position in orbit).

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Wait until we are at the plane-intersection for these 2 orbits. We need to burn where these lines converge. We were northward (thus we are "falling" southward) and to fix that, we need to burn northwards, or towards normal (). Play around with the camera on the other side of the planet to get a better view of the orbit lines moving closer together. When they match in planes, simply stop the burn.

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Now make sure you orbit touches the fuel craft's orbit at 1 spot only. Use that spot to do all future burns. From there you can increase/decrease the other side of your orbit, in order to change your speed (if you are behind the fuel craft, lower your orbit and wait).

The idea is to make both craft reach the orbit intersection point, at the same time. Then its docking time.

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Once the distance between the crafts is less than 5km, you can consider fixing your velocity to point towards the target (). Remember the navball has a Target mode to show this relative velocity. 

As you reach 500m distance, reduce relative speed to around 10m/s. You can do this by pointing mostly retrograde(). To change your direction while doing this, simply look at the anti-target() and retrograde(), then aim at the "other" side around retrograde() away from the anti-target().

The image explains this much better than words. What happens is, the orange line-and-dot (center of navball) will essentially "push" the retrograde() marker away, and onto the anti-target() marker. This means your velocity vector is pointing directly at the target, and you will almost hit it if you do not make changes.

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Keep dong this trick slowly and gently so you keep moving towards the target. Once close enough, slow down to near 0m/s relative speed. If you are comfortable with docking, you can do this without ever stopping first.

Important bits here: Set the other docking port "as target" with double-click (or right-click menu). Set your own docking port's "Control from here". Now look at the navball and make sure the prograde and target markers line up perfectly, and keep them lined up with spacecraft control. Then just wait until they drift into each other.

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Do the same for the other side (this fuel pod is 2 tanks, remember). When done, make sure any staging is still correct, lock the fuel in the center tank if you don't trust docking port fuel flow, and thats it! Time for a Mun landing. I hope you made a note of the total dv before docking. After locking fuel here, add the new dv number to that, and that will be the total dv you have available. 

For this one we got 1743 + 1441 = 3184m/s dv

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Do a usual Mun transfer, but this time make it a habit of keeping an eye on those fuel pods. They need to stay balanced in fuel (shouldn't be a problem), and they should be dropped before you use fuel from the core stage.

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I learned from the past mistakes in Mun transfers. Its much safer to leave AP on the lower side of the intercept.

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Burn retrograde at PE to get into orbit.

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Try to land on the daylight side. Start with a low orbit (8-10km), drop the PE just low enough to make the orbit line hit where you would want to land.

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Im planning on landing at the orange cross I doodled on screen. Set the altimeter to landscape/surface mode, so it shows the actual altitude below you. Set the navball to surface mode.

Hold down ALT and right-click on each part you need to operate for this. Those fuel pods are going to run out during the landing burn, but don't panic. The locked core fuel tank will make the engine suddenly stop. When that happens, you need to click both undock button, and then both fuel unlock buttons (you can easily do that in 10 seconds, and you will have even more time available to do that, so don't worry).

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Pop those fuel pods off, it looks really cool!

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On final landing, take it easy. Any speed less than 6m/s is technically fine for the engine bell you are landing on, but less than 3m/s is safe. Lock SAS into retrograde, and gently feather the throttle.

• Don't use Z / X to max-out or kill the throttle in quick steps, it makes landing so much harder
• Feather the throttle slightly up and down, find the sweet spot where it keeps your speed between 5-15m/s, and just work from there to get to the surface with a 2m/s speed

At the surface, press X (or just throttle down). Around this time, the retrograde lock probably isn't working anymore. You can pick radial-out (if the navball is in surface mode) and it will point exactly upwards into the sky. This will keep things steady while you focus on the last steps of landing.

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Do not forget that science, all of it. Use the Science storage unit's "Collect all" feature to cram the science into that white box. This leaves temp/barometers empty and ready for more new science.

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If you finished some contracts just now, first go back to the space center and checkout any new contracts that you might get right here on the Mun, maybe there's some easy money.

To efficiently get back up into orbit, you need to spend the smallest amount of time between being Landed -> Orbiting. Find the 90° heading (east), and tilt(pitch) over to about 45° into the horizon in that direction. Press Z for max-thrust to immediately take off, and immediately pitch down to almost flat horizontal as quickly as possible (barring any mountains in your way, then you have to point higher).

Once your AP is at 10km, stop burning, coast to AP and circularize. 

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To get back to Kerbin, we do the usual ejection burn by imagining the exit trajectory to point parallel to the Mun's orbit. I burned until the velocity (in low orbit) was about 810m/s. This was enough to exit Mun SOI and end up in a Kerbin orbit with PE 331km. Not bad, but i would go for 820m/s if i did it again.

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The rest has been covered by previous missions, just get a 30km PE, use up the last fuel on reentry, detach that death-trap high in the atmosphere and hope the parachute still works 

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This power of docking extra fuel can really make most missions possible now, at least in terms of hardware.

Edited February 5, 2021 by Blaarkies

[paul_c]

There's some handy tips there! Thanks for the update.

[Blaarkies]

Free to mine Minmus science
Album 10

After cleaning up those Mun contracts, I finally have 2 slots open again. I immediately found a Land and Return from Minmus contract, this would pay for itself and bring back loads of science. But to get more science, i would need to bring material bays with, and for that i would need more fuel than my previous docking machine did.

I had this idea about adding boosters on the launch pad to increase my payload to orbit slightly. I left some docking ports on the lower sides of the final craft, but I first "launched" these 2 contruction vehicles out. They have steering wheel, and braking wheels, and also a Juno jet engine to move around.

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 I put 2 of them out by the Crawlerway (so they don't obstruct the new vehicle since they are not on the launch pad). After they are in position, I create the craft I will be sending to space.

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Drive them up to the rocket, slowly. It doesn't need to be that gentle, but you want it to align properly at least.

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It works! 25tons of rocket on the launch pad. This is a promising step up from 18tons.

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Before launching this, check your staging. Things change when you do out-of-VAB construction. The docking ports' "Enable Staging" feature doesn't always seem to work. To be safe, I keep both those windows open in order to quickly click both undock buttons when the fuel runs out.

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This gets into orbit with quite a bit of extra fuel left, this is very promising.

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I leave Jeb in orbit here, while tending on the fuel pods. I send 2 of these to rendezvous with Jeb and dock onto his craft. What makes them special, is the 2 relay dishes I packed on each of them. Its a free comms network (not a good one, but its super cheap at least). I used the leftover fuel to move them to a higher orbit.

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After docked, i have a lot of extra fuel on this craft. But we still need the science pods.

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Since the science pods are light, it "would" be possible to send 4 of them on a single launch...but I don't have fairings and the frontal drag is going to be way to bad to handle. KSP really punished you for having parts of different sizes not mesh together (size 1.25m <-> 0.625m), thats what i get for connecting those Material bays with Junior docking ports.

In the end, i decided to play it save and do 2 launches. It was a good call as this thing was already hard to control in the atmosphere. I was cutting it close on my funds though.

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They dock together just like the other parts, nice and simple. Between the Materials bays, there is a tiny separator(decoupler) to save on dv on Minmus. This might have made the launch harder than it should have been.

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Now burn for Minmus transfer. The same as always, wait for Minmus on the map, and match AP to Minmus orbit

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Its a delicate transfer, and i have not hit a bullseye during this challenge yet. It does feel really good just even skimming the SOI without any fancy tracking station building.

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Landing is the same as the Mun, just easier. Get into a low orbit, and drop the PE just enough to touch mountains. The craft is moving towards the west ⇦ here

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Stay as low as possible, burn as late as possible...but also be careful. Try and balance that.

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Remember to collect all 5 science experiments. Materials bay, Goo, Temp, Barometer, Crew report. When clicking "collect all" on the science storage unit, it will count up in multiples of 5, and easy way to notice if you missed anything.

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Make a small hop to the next biome. I find 45° pitch to be optimum for covering the most ground distance, but this pitch should decrease the further you try and jump.

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Keep an eye on those fuel pods, drop them as soon as they are empty and don't be caught off guard with a dead engine because of this manual staging you are responsible for.

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Keep doing hops to the next closest biome. For this distance, I aim to hop at a 30° pitch, and I would go lower for places more distant, but at 20° you run the risk of hitting mountains.

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The science pods were done, but i still had fuel left. Might as well do the rest of the biomes while I'm here.

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Even the north pole wasn't off limits

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Once I finished the 7th(?) hop, I felt a bit low on fuel, wasn't sure if there is any obvious biome that i missed. I decided to go back to Kerbin and end the mission. Lucky desert landing for a bit more science.

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Got offered an Eve flyby contract...i don't see that happening too soon, maybe i'll try but it seems near impossible without a kerbal onboard.

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[Blaarkies]

Look ma, no hands!
Album 11
I saw this silly contract about going to Eve, no way I'm doing that with caveman tech   But the more I thought about it, the more plausible it looked. The first of these contracts are always just flyby's, what can go wrong? (they literally say that in the contract details )
Anyway, before I can seriously try that, I need more funds (and maybe an extra science node). And if in the meanwhile that contract changes to something closer, so be it, contract rewards are good either way. For science, I had an intricate plan in mind (more about that in a bit)

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Tried an improvement on the out-of-VAB constructor vehicles, this was supposed to dynamically offset the COM before and after the booster is released. It didn't work that well really.

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Jeb has been mocking zombie movies lately 

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Addon boosters like the last time (but these have a small LOX header tank that feeds through the docking port to the core engine). Remember to undock them to drop, the staging thing isn't working for me. At this point, I had struts unlocked, yet I keep forgetting to auto-strut these boosters.

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This contract required a "station" in solar orbit. Just add the minimal required parts to complete it, and yeet it out of Kerbin SOI.

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Had a few satellite contracts. With fuel lines unlocked, I could connect some tanks where previously impossible. This design flies great since it is so top heavy, but also detaches an empty tank even during the final stage, boosting dv somewhat. To make lots of funds at this point, I just repeated these rules:

• Pick 2 satellite contracts in the same region, and do both with the same craft
• Be stingy with science equipment/parts. They are generally the more expensive parts of the craft
• Add some relay dishes to improve your own comms network "for free"
• Matching satellite contract orbits is like rendezvous without the last step, super easy

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After funds started looking comfortable, there was one experiment I still wanted to complete before moving on. Getting a Kerbal into orbit, outside of the capsule. If I can prove this possible, theres so much more science waiting on Minmus. I tried a few different designs, this was one of the more ridiculous ones. The capsule is upside-down in that fairing, the kerbals should drop out into the fairing "bucket". But the "Hatch obstructed" warning kept this from working. Was for the best anyway, he didn't even have parachutes packed!

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This design finally showed promise. I used Bob in the hope of getting more science done this way, but also the Kerbal's skill wont play any part in most of the mission since the have to stay outside of the capsule. Bob could easily exit the lower capsule, and precarely walk +15m above ground into the service bay.

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It does not look comfy at all.

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Remember to put on that helmet. If you don't, they go pop on the way up to space!

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Pop off that placeholder capsule, the parachute doesn't seem necessary...maybe, I don't know.

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Launching for a polar orbit is much the same as previous launches, except aim for about 340° heading (or 20° towards west from prefect north). The reason for this is to cancel out that eastward momentum of the craft standing on the launch pad (which is stuck onto a spinning Kerbin). If you don't do this, you will end up with a ~70° inclined orbit, in contrast to the perfect 90° polar orbit.

Somewhere during the launch profile, when switching from Surface to Orbit navball, you will notice the heading change of the prograde marker. Above 40km altitude, it really doesn't matter if you aim a little bit off from surface-prograde, use that to fix orbit-prograde to aim directly north (since your orbital speed is still low at that point, it is cheaper than doing it after circularization)

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Got circularized into a good enough orbit. During this, keep your hands off the time-warp buttons! Time-warping will ignore physics collisions, so Bob will glide through the service bay walls as if he is "Marvel's Vision" using quantum tunneling. For Physical Time-warp, it is still risky because Bob's helmet is barely fitting inside the service bay...it might cause a kraken attack.

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Rise and shine Bob, time to have some science experiments for breakfast.

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I waited in orbit until all biomes had their EVA science collected. Be careful with that EVA fuel, it can't be replenished by simply boarding the capsule again since that would end the mission (try adjusting the new EVA throttle limit). After all low orbit science was collected, there was some LOX fuel left, enough to reach high orbit. Just get back into the service bay and do the burn. Once Bob is outside again, you can safely time-warp to get to AP.

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This was pretty good, got some extra science, for a mission that wasn't that expensive, and also proved a prototype.

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With this idea tested and proven, it seems entirely possible to have Bob hold on for dear life on a ladder on a Minmus hopper. He could restore science experiments on each hop, and collect 2 different EVA reports for each biome, and use some deployable science on Minmus, and the cool EVA science briefcase in orbit high/low and surface! (the no time warp part is going to be tedious though)

 

 

 

Edited February 8, 2021 by Blaarkies

[Blaarkies]

Flyby Eve
Album 12
After testing the EVA craft, I wanted to test out some of the last requirements for the final Minmus mission. Bob will need to place 4 deployable science parts. I built an excursion vehicle to test this out and also gather some science from the Mountains biome.

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I found one of the Boabab trees, I was hoping to get some science from it, but you need the scanning arm to get anything out of it. Seemed like a great place to deploy those science experiments though.

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The excursion never even made it to the Highlands, it had broken wheels when I was halfway to the Mountains. Decided to end that mission, and back at the KSC i was greeted with this. Flyby Eve, and return for around 130K funds! Its no easy task, but the payoff would be huge when adding the "World Firsts" rewards on top of this contract.

It will be much harder than intercepting Minmus, I will need enough fuel to make huge corrections in Kerbol orbit since I won't be able to accurately predict anything while inside Kerbin's SOI.

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I need to get much more fuel into orbit, it would be far easier to do this mission then. Comparing craft costs, I found that its much cheaper per ton of fuel if I add Thumper boosters to the rocket. This is because I need at least 1 probe core (and its required systems, like SAS, battery, solar, comms), 1 Terrier, and 1 Reliant per launch. That is a large fraction of the mission cost, but I can offset it by doubling the payload to hold 2x of those 2.25t fuel tanks.

I tried several iterations of the out-of-VAB constructor vehicle before I found something that doesn't topple over with these boosters. I came up with this

• Adjustable counter weight ballasts
• "Reversible" Juno jet engine (it doesn't point inline with the vehicle, as to avoid having the exhaust hitting the vehicle)
• Top of the booster is a small fuel tank, to feed the core engine for a while
• The docking port is placed onto the LOX fuel tank, and moved downwards via the translate gizmo
  • Without doing this, the fuel does not flow through the docking port

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37.5t on the launch pad. It can probably handle a slightly bigger payload as well, but I'm playing it safe for the first launch.

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The docking ports don't line up perfectly when docked under gravity, and they sag down. No problem though, remember to auto-strut them and then go back to "Space Center" (via escape menu) where you see the KSC buildings. Click back on the craft, click fly, and you will see the boosters are well aligned.

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Before you launch, it is extremely important to check everything that could possible go wrong. Follow a checklist if you have to:

1. Staging. Moving stages around will affect the following steps, do it first then you don't have to repeat other steps
2. Auto-strut boosters. They should already be auto-strutted at this point, but its worth checking
3. Fuel flow priorities. Higher positive numbers are first used to feed engines,  so get the highest number on those booster LOX tanks, then the bottom core tank
4. Setup HUD. It will be a very busy launch trying to tame a slapped together rocket like this. Get this stuff ready beforehand
   • Hold down alt to right-click open up many windows
   • Docking port staging has failed me too many times. Open up both of them, check that it has the "Undock" button (you will be clicking those when reaching that stage)
   • Open any relevant windows you might need (I want to stage when the booster LOX tanks run out)
   • Turn on SAS
   • Switch to orbital info
   • You can pin important windows if you are afraid of miskicking somewhere (which will close them)

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This rocket's TWR is quite high (and that's fine since its very aerodynamic), so pitch over immediately. The Terrier stage has a low TWR, and will need some time to reach orbital speed. If this first stage throws it into a too vertical trajectory, it becomes hard to use the Terrier efficiently.

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Click those undock buttons rapidly (or pause the core engine for a moment) to avoid sudden yaw rotations. Still safe? That was the hardest part, now  just keep pointing prograde, check the AP and try to empty the core stage before AP reaches 70km. Mine staged at 46km, with AP predicted to be 60km. From there the Terrier will do the rest.

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Those fairings are amazing! The previous launches were so much more finicky.

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Get to orbit, rendezvous, and dock the pieces.

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The 2nd of these super fuel pod launches.

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And also a Science pod launch. After everything is assembled in orbit, it looks like this:

All fuel tanks are 100% full, except of the bottom orange can, that used about half of it to reach orbit. Its got 9t of docked fuel pods, and docked 2 Material+Goo pods. I left the refuel launchers docked on the same side, I hope to squeeze a bit more dv out of those via periapsis kicks.

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With this done, its time to start looking at an Eve launch window.

Wait until Eve is about 54° behind Kerbin. Thats really hard to eyeball, so im just going to guess at when its "a little bit" more than 45°.

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At this point, zoom into Kerbin and find where you need to start the ejection burn. It should be something like 25° counter-clockwise, measured from the bottom of the cyan line (Kerbin's orbit). This funny angle is required due to the fact that you do not exit the SOI at exactly the opposite side of your current PE. As you increase speed beyond +3000m/s, your orbit will sever its loop  (and look almost L-shaped, having its corner close to Kerbin) and you will actually follow a hyperbolic trajectory.

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Remember to tune the engine throttle limiter when burning multiple engines on an asymmetrical craft. These satellite boosters had lots of leftover fuel, I decided to try and make some use of them.

Look at he orbital velocity at PE, you can use this to determine if you have completed a burn. Low orbit velocity is about 2270m/s. If you need to burn 1050m/s towards Eve, just add that onto of the previous number, and wait until you hit 3320m/s (this only works at PE, and PE must be like 80km or less, as if it was part of the low orbit)

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The trajectory looks fine from here, but the inclination is about as bad as it can get between Kerbin and Eve. It cost about 300m/s to fix that. Everything here is really just rendezvous, but with planets, and around Kerbol instead.

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I locked all the fuel tanks, excepts the ones I am actively using. When the engine stops, it means those are obviously empty. Its safe to eject the spent fuel pods, and throttle down the engine, and then unlock the new pair of pods.

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The intercept was extremely close, I could literally see Gilly's orbital lines. In hindsight, looking at this image, it is very clear that i was going to overshoot. I was moving +600m/s faster than Eve, so even if I did hit the SOI, it would need a hard burn to cancel that sideways velocity.

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At this point, I realized i will need to match orbits to rendezvous with Eve. Don't this unless you have no other choice, its very expensive to adjusts orbits in interplanetary space. Check the dv display, it cost me around 850m/s to do this simple maneuver. 

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I did eventually get an intercept, but look at the mission timer   "This Little Maneuver's Gonna Cost Us 51 3 Years"

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I fixed the orbit to have a PE about 87km. This is crazy, because Eve's atmosphere starts at 90km, and it burns anything that's unprotected even that high up...but there is sweet science in those upper fumes. The screenshot missed it, but the materials bay + goo actually exploded pretty quickly, luckily i had enough time to do the "Collect all" from the science storage container. Everything else survived though, even the other side of the docking port holding the science.

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After being filled up with all the science i could easily pick here, I was going to wait for a good launch window and use my current orbit to get to Kerbin, but my AP was somehow still above SOI  

I would have to rendezvous with Eve again and hope to do it better this time. This took another few years of mission time.

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After getting into orbit again, I waited until the right time to eject towards Kerbin.

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It took many more years, but at least the final stage had a lot of dv leftover. I was almost certain I can get this back to Kerbin...i just wasn't sure when.

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After basically matching orbit with Kerbin, and always overlapping Kerbin SOI, I could just wait it out until an intercept happened.

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Landed in a pretty idyllic location.

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Got some good science out of this, but also enough funds for many more missions. I'm glad I packed so much extra fuel on the mission. If the initial intercept was perfect, I would have tried to land on Gilly. If the intercept was bad, I had enough fuel to fix that, so its a win-win at least.

Lessons to be learned from this:

• Playing rendezvous with planets is extremely expensive compared to proper intercepts from low Kerbin orbit
  • Burns in interplanetary space is not as bad as I thought. It might be an option for Ion/Nerv engines past Duna's orbit probably?
• Ejection burns take time. When setting them up, take into account that Kerbin's orbital trajectory will move "underneath" your current escape trajectory
  • Maybe add 5-15° on that angle (depending on how long the periapsis kicks take) to compensate for that?
• Even with the bad planning/luck, it is possible to get more than 2.25t of payload into high Eve orbit. Another craft can bring the fuel needed to do a Gilly landing, and still have the same amount of surplus left over as I did

 

Edited February 11, 2021 by Blaarkies

[JAFO]

On 2/1/2021 at 6:14 AM, Blaarkies said:

I'm still stuck with that "Escape atmosphere" contract, taking up a valuable slot of the total 2 slots we have for contracts.
To cash in on it, we launch...a thing! Its simple really, get the capsule up to +70km, but also safely back down, or risk having 1 kerbal less. It is tempting to do this before unlocking decouplers, but its not worth the risk. Even a Flea booster on the back of a capsule can be enough to flip it, into a really aerodynamically stable orientation. Those dart too quickly into the ground for parachutes to even open up.

Heh heh.. I ran into that problem a while back. But managed to find a solution that didn't require decouplers.

May I present to you, the good ship "Another Fine Product From The Nonsense Factory".
(Bonus points if you get the reference!)

The craft file can be downloaded from KerbalX here. (Yes, I put all my own favourite Caveman craft on KerbalX, so that I can easily import them into new challenge attempts, using the KerbalX mod, thus saving me a lot of time. Yup, that mod is allowed in a Caveman Challenge attempt, as all it lets you do is upload/download craft.)

 

 

The fins on top help prevent the Capsule + Flea from becoming a lawn dart on re-entry. Of course, they do make the craft a little less than atmospherically stable on the way UP. The tiniest deviation away from going exactly straight up will result in disaster. (And yes, there are 4 goo canisters. Symmetry is essential in this instance.)

Successfully getting this thing to space is strictly a matter of "Keep your hands and feet away from all controls that are NOT the space-bar." Also, the last 2 stages should not be fired until it is well above up around 20,000 metres. Just how far above 20,000 is necessary, I'm still determining. Something (maybe the atmosphere) appears to have been tweaked a little since I first flew this baby back in v1.4.2. My first use of it in 1.11 was unsuccessful due to me getting the staging timing wrong (see my next post), and so the second try, I waited until it had lost most upward velocity before firing up the last 2 Fleas.

Edited February 16, 2021 by JAFO

[Blaarkies]

On 2/15/2021 at 9:14 AM, JAFO said:

Heh heh.. I ran into that problem a while back. But managed to find a solution that didn't require decouplers.

May I present to you, the good ship "Another Fine Product From The Nonsense Factory".
(Bonus points if you get the reference!)

This is pretty good, i got so focused on the capsules blunt end that i didn't even consider something like this. How high does it go with 5 stages of Fleas though, i would guess close to orbital unless drag slows it down too much.

Also do the girders burn off easily during hot-staging?

[JAFO]

7 hours ago, Blaarkies said:

This is pretty good, i got so focused on the capsules blunt end that i didn't even consider something like this. How high does it go with 5 stages of Fleas though, i would guess close to orbital unless drag slows it down too much.

Also do the girders burn off easily during hot-staging?

I ran a couple of tests just now, and found that in my description above, it turns out I was just flying it badly on that first attempt. Just rusty, I guess.

The correct launch procedure is; SAS on. (forget this, and it's game over) Hot-stage the first 3 stages one after the other, without any delays between them. You want to shed excess weight/drag as quickly as possible, and also build up all the speed you can. Your apoapsis will top out at around 19-20km. Coast up as close to this altitude as you feel comfortable with.. but you want to kick off the fourth stage before you get too slow.. 50m/s is as slow as I feel comfortable with. Again, light both stages off one after the other, and coast up to space.

But to address your questions;

The girders burn off quite easily. With the girders on, it reaches about 80km. Without the girders, the launch gets a little hairier, as one of the side-mounted burnt-out fleas will explode before the other side does, so it gets a bit of side-to-side wobble up, which is scarier than it looks, as the craft will sort itself out after a few seconds, and keep going up. The girderless version can reach an Ap of 95-100km.

(The same craft WITH decouplers can reach an Ap of 120km or so.)

Edited February 16, 2021 by JAFO

[Blaarkies]

Hitchhiker's Bob's Guide to the Galaxy Mun
Album 13
I still had the plan of doing a complete science landing for at least a few biomes. In one go, I want to collect all the science a biome has to offer. I need about 200. First, I need a kerbal in a command pod for crew reports (might as well be a good pilot as well). Secondly, we need Bob outside to handle science experiment restorations, deployments, and extra reports. 

This here is the lander which will be doing the bulk of the mission. The 2nd image shows how it has a docking port "magazine" slot in the middle where we can swap fuel pods for full fresh ones.

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I took a short break, tried getting some cash from discovering the pyramids. It should be easy, until I found that the "Extra launchpads" option is disabled by default (even on career normal). Its not explicitly stated in the challenge's setup, but we all know the Caveman challenge defaults towards the hardest difficulty options, so im sticking to that. Thus Valentina flew from KSC towards the desert runway, until the pyramids appeared. Came in for a landing and then...well, any landing you can walk away from is a good landing, right? 
The pyramids cash reward was useless, 480.  I don't know if the runway has a different science biome (because I crashed way ahead of that )

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Back to that Mun mission. The magazine lander would use TL-400 tanks (2.25t), so i tried launching 3 of them at a time. Thing got out of hand quickly, the extra part count and extra mass forced me to split the bottom stage off into a separate vehicle. I did not like the flimsy construction of this, and it made the rest of the construction difficult as well. I recovered all of it, and started over...

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I opted for a 2.5m bottom stage, and the usual thumpers. It feels odd going for launch 4 times, and still not being ready to go to space.

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So close. I measured the distance in the VAB perfectly, compensating for wheel suspension. I think the parts sag a little downwards (the heavy tanks on the construction vehicle's frame probably bends it as well). Time to drive the base away, recover the top stage, and re-launch after moving it downwards by "about 2 decouplers"

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Perfect fit, not really. Start auto-struting all the heavy parts. I used a mix of grandparent and root settings here, about 7 parts in total were strutted? Anyway, things might still look crooked (and may very well be). To fix this, move to another scene and back. The simplest way is to decouple the construction vehicles, and recover them. That takes you to the KSC overview, and from there when you switch back, this rocket will suddenly look much safer.

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49.82t on the launch pad. Same rules as before, check staging, struts, fuel flow, HUD...then launch.

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Prettiest thing i have seen my whole life 

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Many docking later, we have a near final construction. The rest of the launch were done with the simple 2x TL-400 tank launcher, its much more reliable and easier to launch than the 2.5m monster.

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Bob is at this again. Early morning launch, do a wide-rope walk into the chamber of hazard-pay, and off we go!

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The rendezvous was painful. You can warp at 4x physical, but thats all. You have to wait it all out, or risk Bob wasting EVA fuel when he warps outside the box. 
At this point I still believed I was limited in EVA fuel. Turns out you can refill them by moving the EVA pack into and back out of any container, then they are refilled

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There was barely enough space on the ladder-hold for Bob, but it worked. Remember to lock/fuel-flow those tanks so you don't use the wrong fuel tank for this burn. The journey to the Mun is going to be a long on (IRL) since time warping has been a luxury we don't fully own with Bob on EVA. Keep him close to the craft, and you should be able to do 100x time-warp. Just watch the Mun SOI and be ready for the next burn.

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The highest any Kerbal has ever been, both in spinning around vital spacecraft parts outside, and also altitude. This little experiment added a few science points, but sadly its a global experiment (doesn't care about the biome).

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Reaching PE, its time to slowdown into orbit. The TWR is still very low at this point, so there is no risk of falling off the ladder.

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Capture EVA reports while in orbit almost constantly. There's lots of extra science to be had, since the Mun has so many biomes even on a simple equatorial orbit. Apart from that, Bob is great for using that materials bay as often as you like. Pack the results into both the capsule and the science container to get duplicate results back home.

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Time for docking. I tried doing this in the dark because I didn't feel like waiting. It was really hard, at least Bob's EVA headlamps help a bit. First we drop the spent fuel pod, then we line up the payload at the top and release that. Now we try to dock sideways into an uncontrolled stack of debris. When done, detach from the fuel-pod-station.
A different design with the pod at the top (and extra fuel lines running down the sides) would have been easier. I did this center-magazine style pods because of the docking port fuel-flow limitation (it needs to be directly linked to the fuel tank<->engine)

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Here comes the fun part. Go in for a shallow landing trajectory, on the edge of 2 biomes, while checking up on Bob for more science.

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I spy a special rock in the distance.

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Im going to ignore the horrible fall Bob just had, and only show the Fee-fi-fo-fum pose he is doing right now. On the side of the lander are some containers, used for deployable science. Get all all those out, and do all the science you can find.

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Off to see the rock we spotted. Looks like a Mun stone! These are worth 24. Climb ontop, right click the kerbal, and click "pick up stone".

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Quick jump to the next biome. It takes less than 700m/s dv to land/accent the Mun, so whatever you do, make sure you don't use that last 700 for anything else (600 if you are brave). A 200m/s dv jump on the Mun can take you almost across one of the huge craters, but remember you will need 2x that since you also need to slow down and land at the end of the hop.

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Collect all the science at the next biome, and launch for orbit. Aim ~45° and full throttle to orbit, aim at the flat horizon as early as the mountains around you will allow. A very low TWR lander can still start at 45°, and just hold that for longer before aiming at the horizon.

The major reason that Earth/Kerbin rockets start by going upwards, is because moving sideways like reeds in the wind induces an insane amount of drag on the rocket (completely circumventing the aerodynamic pointy design of the rocket). Going upwards allows the later stages to "powerslide" sideways when they are out of the atmosphere, doing more with little engines.

On the Mun, you can go sideways as early as possible to start reaping the rewards from centripetal forces helping you against gravity.

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Dock back at the fuel pod station, eject another "magazine", and ready for another landing. The first pod was special, it had the extra science experiments. I stashed Bob's now unnecessary parachute in there, as well as the spare EVA packs I thought i would need. This means I will have a tiny bit more dv in the next landings.

Bob's adrenaline is still running strong, he hasn't yet realized that the budget cuts led to only one capsule being launched to the Mun...

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Check those fuel locks, detach the fuel-pod-station, and off we go to landing #2. Its the same as before, but this time land somewhere different. Try to remember where you have landed before, and aim for new biomes. All the massive craters are their own biomes, surrounded by high/mid/low-lands. You can use that to do an extra hop across the biome border.

These Mun stones are not hard to find actually. Its lucky to find them on the very first landing (that's what new players expect), but over the course of 3 landings you would most likely been within 1km of such stone.

The science rewards after this mission confirms that only 1 Mun Stone counts towards science points. Its not an actual stone you take back to Kerbin, but more like the science data from an experiment part called "Mun Stone". So no biome differences, and they are only on the surface, which means you can't get multiples of it 

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A small hop to the low lands biome. One day I will make a pretty visualization about launch pitch vs distance, but for now we need to trust the math that a ~45° launch gives the most distance for the least amount of dv. This is only true on a flat surface, it becomes warped around the Mun's curvature. To compensate for this, draw an imaginary floor from your origin to destination, then aim ~45° relative to that (it just means the farther the destination is, the closer to horizon you should aim)

This is still over simplified, since the gravity vector will change significantly over a very long sub-orbital hop. But you won't lose much dv by eyeballing small hops

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This is what happens when the pilot gets distracted by Bob peaking through the capsules windows

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More docking. We have fuel for 2 more landings left.

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The Canyons are pretty cool (thanks @paul_c). I overshot the initial landing spot quite a bit, its easy to overcorrect when you know there is no quick load.

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These mini craters don't have any science for us, we need one of them fancy computer arms 

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Bob had a mishap, Jeb doesn't see what's wrong about landing like this. The pod has enough reaction control to tilt up about 30°, thats all we need to get air space-born

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Back into orbit. This is embarrassing. I did a full rendezvous towards an empty tank  The craft naming probably got messed up when I detached it last time (maybe i had the root-part of the fuel-pod-station?)

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Tracked down the final fuel pod, but docking became increasingly difficult each time as the "station" got smaller. I tried Kerbal-assisted docking, and it worked well enough.

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Bob making Mun-angels on the very last landing. He got up quickly when radio chatter considered the implications of leaving him there.

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Back to orbit, wait for the ejection burn placement and burn to leave low Mun orbit at 830m/s (too much, try 810m/s for a nice Kerbin PE). The many satellite orbits show how busy you get with extra missions. Lots of these are just fuel pod launches at least

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I felt bad leaving Bob on the Mun, so I got him back into LKO with a fully fueled EVA pack. He still has a pod from his initial bucket launch floating around Kerbin, that 600m/s dv EVA pack should be enough

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Those extra hops completely exceeded my expectations. I needed around 200, now I have 600 

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And that unlocks everything a caveman could ever dream of learning

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This marks the end of my challenge entry to the Caveman Challenge - Diamond. This required about about 38 hours of playtime according to steam, but I'm sure it can be done in less if you do not over build missions.

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I'll add more learnings and lessons at the top of this thread 

Edited February 21, 2021 by Blaarkies

[JAFO]

3 hours ago, Blaarkies said:

This here is the lander which will be doing the bulk of the mission. The 2nd image shows how it has a ...

Am I the only one these images aren't showing for?

[Blaarkies]

2 hours ago, JAFO said:

Am I the only one these images aren't showing for?

I just checked in an incognito tab to see the "public" view, and those images show up...after a few seconds though, I think this thread is loading all the images at once 

Try the album link (Album 13) and check if that shows anything, all the images are there, as well as some extras not shown on the thread

[paul_c]

(The pics show fine for me)

In my first career I got to the stage of doing "extract xxxx ore from Minmus and return it to Kerbin orbit". I had a huge base station with mining kit on Minmus so I used to send a craft with empty ore tanks (and a fuel tank) with a little engine, designed just to get into orbit then leave Minmus SOI to fulfil the contract. The thing ended up about 40t and 1.1TWR once it was full of ore, and the base was at the west edge of Greater Lakes (so it was on lowlands - better ore concentration - but still flat). The take off and departure had the whole lake to gain height so I used to give a 10 sec squirt upwards then shoot along the lake pointing only about 5-10deg above the horizon and gradually build height to just make it over the hills, its a very fun way to take off when you are confident it will work! 

Its good fun on the Mun too but for safety, I'd always be checking I will clear the terrain comfortably, if you land in a crater its quite deep.

If you ever need to land in "Canyons" its aligned pretty much east-west so that's always an exciting departure, not unlike Innsbruck Airport.

[JAFO]

12 hours ago, Blaarkies said:

I just checked in an incognito tab to see the "public" view, and those images show up...after a few seconds though, I think this thread is loading all the images at once 

Try the album link (Album 13) and check if that shows anything, all the images are there, as well as some extras not shown on the thread

Hmm.. I wonder if it's my VPN that's causing things to be weird? Although now I think about it, after you made that first pic public, I could see it no problem. Weird.

Anyhow, the album link works fine for me.

[xendelaar]

fascinating challenge! you made me want to redo the challenge again!I don't know if I want to go all hardcore  like you though haha. 

[paul_c]

On 2/17/2021 at 1:07 PM, Blaarkies said:

A small hop to the low lands biome. One day I will make a pretty visualization about launch pitch vs distance, but for now we need to trust the math that a ~45° launch gives the most distance for the least amount of dv. This is only true on a flat surface, it becomes warped around the Mun's curvature. To compensate for this, draw an imaginary floor from your origin to destination, then aim ~45° relative to that (it just means the farther the destination is, the closer to horizon you should aim)

This is still over simplified, since the gravity vector will change significantly over a very long sub-orbital hop. But you won't lose much dv by eyeballing small hops

Interesting stuff! 

I've never looked too deeply at it but in theory:

1. Burning in one direction, then changing AoA, then burning in another direction is inefficient. It would be better to use just one direction then stay pointing that way to do the "sum vector" of the two burns.
2. Anything not pointing directly at the horizon is inefficient, because you're not doing anything for orbital horizontal speed, just overcoming gravity. (But you need a bit of altitude gain for terrain clearance)
3. You are of course subject to gravitational forces all the time (its what orbiting is...) but the longer you are "suborbital" ie Pe<0 or Pe<terrain, the more time you need to burn to overcome the gravity vertically, ie not pointing at the horizon. That might have occurred before in a liftoff/gravity turn, or it might be needed later if you need to point the nose up near/after Ap.

So in theory, the "optimal" Mun-leaving rocket would find a flat/downhill section, tip over to 89.9deg and burn an enormous thrust engine to orbital velocity real quick (like wot a dragster can accelerate 0-100 in its own length!). And the "worst" Mun-leaving rocket would have TWR 1.00001, do a long long vertical burn to give enough height, turn horizontal and eventually reach orbital speed and avoid colliding with terrain.

Of course, the bigger engine cuts into the payload/fuel weight allowance, so we don't take big engines to the Mun. So the optimal angle to burn at is related to the TWR? 45deg is a good ballpark; but if you've done a burn, then wait, then do a horizontal burn at/near the Ap you're inefficient (see rule 1)? If you can do one long continuous burn at say 20deg, would that be better? Or a 'grace' period of starting say vertical-45deg for a few seconds then tipping to (say) 15deg ASAP, for terrain clearance concerns?

Also of course, well done on completing the challenge!!!!!! NCD time!!!!!!

[Blaarkies]

4 hours ago, xendelaar said:

fascinating challenge! you made me want to redo the challenge again!I don't know if I want to go all hardcore  like you though haha. 

Im sure you can do this Diamond challenge , its one of the reasons i did this instead of NCD. In Diamond there is a steep "science wall" before reaching the Mun (its hard to get enough science to unlock that Terrier engine), but after that is just perseverance to collect all the science you can get your hands on .
But in NCD, there is a "science cliff" you need to climb, but your climbing gear equipment is at the top of that cliff 

 

18 minutes ago, paul_c said:

I've never looked too deeply at it but in theory:

...

Of course, the bigger engine cuts into the payload/fuel weight allowance, so we don't take big engines to the Mun. So the optimal angle to burn at is related to the TWR? 45deg is a good ballpark; but if you've done a burn, then wait, then do a horizontal burn at/near the Ap you're inefficient (see rule 1)? If you can do one long continuous burn at say 20deg, would that be better? Or a 'grace' period of starting say vertical-45deg for a few seconds then tipping to (say) 15deg ASAP, for terrain clearance concerns?

Also of course, well done on completing the challenge!!!!!! NCD time!!!!!!

Thanks, it took much longer than i expected to be honest
Some really good points you got there, i didn't think of that. I was thinking of it like a simple ballistic cannon ball example: Given x speed, what pitch will result in the greatest distance. But any rocket obviously does the burn over a short time period at least. The visualization i thought of, is building a craft with like 10 of those Shrimp boosters on decouplers, each aiming at a different pitch, and launching them at the same time. The map will show which ones goes the furthest.

Edited February 18, 2021 by Blaarkies

[paul_c]

Ballistic is probably useful for optimising suborbital hops. But for take off to orbit, its putting so much energy in for the horizontal element, that its a case of "how do you best put it in over a finite period of time".

[JAFO]

On 2/18/2021 at 3:13 AM, JAFO said:

Am I the only one these images aren't showing for?

Since yesterday, the images are showing just fine for me.

Sometimes the internet is just weird.