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Stars to stones: my nanocristalline diamond caveman attempt


king of nowhere
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 If I try a challenge, I try it at the highest level.

One year ago, i considered the caveman challenge - and of course, I had to do it at nanocristalline diamond level. I gave up soon, stating "too much grinding, I don't like it".

Instead, I went on and did a bunch of large scale missions with kerbalism. The last one was 320-year long. Greenhouses require manual harvesting twice every year, and I had 19, so i clicked "harvest" over 12000 times. The mission also required manually servicing the nuclear reactors every three years, again, that's over 100 times where I had to go EVA and fly around the ship. Afer that, I felt I really can't complain about grinding.

So here I am, trying the nanocristalline diamond caveman.

Part 1: the low-hanging fruits

Getting initial science from Kerbin and its orbit

Spoiler

Normal beginning with a roller to get science from the ksc biomes. I got 5 science, I teched engineering 101, to get the thermometer. Made another roller with the thermometer, got another 5 science.

At this point, I took basic rocketry. Maybe it would be possible and effective to harvest more science and get the barometer too, but with basic rocketry I can get to orbit. And in orbit I can at least get my 5 science back. Got some early funding mostly by testing stuff on the ground.

So this is my first orbiter: a tested and true design.

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I'm playing it safe here. It is possible to reach orbit - even high space - with only 14 fuel tanks, but I put in 15 because I know I am unlikely to hit an optimal launch profile the first time. And it is possible to avoid the decoupler, keep the whole rocket together, and recover it all. But a small mistake in reentry profile would flip the rocket, which would then have too little drag to brake properly, and it would kill Jeb. I can make more money with some time, better to avoid unnecessary risks.

So, this orbiter went to orbit, as it was supposed. I keep launching a bit too vertical, but I did include some extra fuel for that. Unfortunately, upon reentry the goo canisters and thermometer melted for the heat. I still got plenty of money for world first, though

At this point I realized I am treating this as a no contract career challenge, which is not. I don't need to actually get to orbit. I only need to get to space to conduct some science. So I made a cheaper, weaker rocket for suborbital jumps

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It did reach space, and it was slow enough that reentry wasn't dangerous. With this I got the low space experiments.

Then I decided to try and do something adventurous: test a thermal shield at a certain altitude and speed. I did regret it, because I kept missing the altitude or the speed, by very narrow margins.

And at some point I tried to keep the spent booster attached to recover it, messed the reentry, and exploded Jeb. Had to restart the career; fortunately, it's still early, and I learned the lesson. Never try to recover heavy machinery on a manned vessel.

I ended up launching half a dozen suborbiters. On the plus side, they fall down at random, and I got ground science from a bunch of biomes. With that, I could unlock survivability.

So I picked the barometer, I made another roller, and I finished mining the ksc for early science. At this point I'm still missing a handful of experiments, but the ksc is mostly spent. I've still got a lot of Kerbin biomes, but going there would require launching an orbiter (which is relatively expensive) and trying to deorbit it in the right place. I'm not looking forward to that. If possible, I'd rather tour the Kerbin biomes in an airplane. So I try to move away from Kerbin, to avoid the risk of locking myself.

I have a rich contract for making a Mun flyby, but it would require reaching orbit with 850 m/s. Make it 1000, for safety. I tried some designs, but ultimately I am unable to make it without the terrier; having to use a swivel for space manuevering increases my dry mass too much. Unlocking the terrier itself is out of the question, but if I unlock general rocketry I'll eventually get some contract to test the terrier.

I need a few more research points, which I can get from high orbit. Just strap a booster on my regular orbiter

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This rocket got space high science and brought it back to Kerbin. Reentry was adventurous. I forgot the cargo bay open, and the thermometer exploded for the heat. Then the capsule flipped, and the crew pod has really low drag and was plummeting to its doom very fast. Fortunately, leaving the cargo bay open generated just enough drag that the parachute could open at 1500 meters from the sea. If I had reentered over mountains, I'd have been toast. I was aiming for desert, but I missed it by a good 1000 kilometers. I really do not want to be stuck mining the Kerbin biomes by deorbiting over them.

Anyway, I recovered enough science to unlock general rocketry.

Then some more money grinding on easy contracts - included sending a roller a few kilometers away from the ksc to take ground measurements. Those things are hard to control, the first one run out of electricity before reaching all the targets. But the contract paid 8000, so it was worth the effort.

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Once I got enough money, I started looking for a contract that would give me a terrier to test. Sure enough, I got one soon.

Now I'll try to make a Mun flyby and collect some science there. I'm confident I can at least land on Minmus with those techs.

Part 2: flyby season

Getting more critical science from Mun and Minmus flyby

Spoiler

Introducing the moonshooter. It does exactly what it says: shoot for the moons

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the first stage launching

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and the second stage, aiming for mun

This rocket has 1500-2000 m/s left once it reaches orbit, which are enough to get a flyby with a lot of extra. I do need that extra, because there's no way to plan a return trajectory.

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On the first try, I hit Mun square on. I needed some course corrections. And then I was on a course to exit kerbin's SOI entirely, and had to burn retrograde with everything I had to avoid losing Jeb in interplanetary space. After that, I was in a 70 km apoapsis; I was about to fall back on Kerbin, but what if the moonshooter came too close to Mun along the way and got steered off course? I gave moonshooter an inclination, so that it would not cross Mun's orbit. And it used the last of the fuel. I had 50 m/s left when I jettisoned the rocket for reentry.

But the mission was successful, and I got 17 science back home. And an additional 4 science granted by the contract "explore Mun". At this difficulty level, everything counts.

Unfortunately, all the biome-specific experiments are stuff I can't run in caveman, which greatly limits the science value of space. Can't do anything more on Mun for now. I must go for Minmus too.

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Minmus is a lot more difficult to pinpoint accurately, so I made myself a tool. I put in apoapsis and periapsis of my orbit, and the tool returns me the orbital period. In this case, I figured since Minmus orbit is 50 days, and it has to make about 1/4 of it, it will be crossing Moonshooter's path in 12 days. And if I raise apoapsis enough that I have an orbital period of 22 days, then I will reach apoapsis in 11 days, just before Minmus. Which will let me catch the moon on the way back.

Everything was correct, except the last sentence. Moonshooter spent longer at apoapsis than I estimated, and Minmus was starting to slip away. So I did the only thing I could try: I pointed the rocket more or less in front of Minmus - without even being able to make a targeting to align properly - and fired.

Unfortunately, I forgot to take screenshots of that part. Of course, it was a very difficult manuever to pull off, mostly coming down to random luck. On the plus side, orbital velocities that far from Kerbin are slow, and Moonshooter still had 800 m/s, so by trial and error  I had enough fuel to eventually succeed.

I entered Minmus orbit with 250 m/s left. I had 30 when I reentered on Kerbin.

But again, mission was a success, and it got a lot of science. Enough to unlock basic science.

Basic science gives a couple of fundamental parts. One is the science jr, the most valuable science experiment. So I went back to mining the KSC for everything that was missing before

Unfortunately, the science jr is also extremely fragile. Putting it on a roller is unsafe. I tried many ways to mitigate this fragility

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Project 1: the onion pods are keeping the science jr away from the ground. It failed, because this thing can't steer

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Project 2: the science jr is very well protected. But this roller doesn't roll very well, and it can't go uphill

I tried many other projects to keep the fragile material bay away from the ground, but none worked. In the end I had to do with a conventional roller, and try to drive it very carefully. Never exceeding 4 m/s.

I still broke no less than 5 science jr, maybe a few more. Those things are expensive. Ouch.

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To compensate, I took this contract that required somebody to walk 3 kilometers to collect eva reports. To my shame, I didn't think to use 4x time warp until nearly the end. It paid 8000, though.

Once more, I run out of easy science, and I barely got 30 science. Can't make any more breakthrough.

Good thing is, there is another part unlocked with basic science that will allow me to land: the stayputnik. By cutting down on weight, it will let me increase deltaV. Equally important, it allows me to take risks I couldn't afford to take with a pilot. I took the contract to land on Mun; it's worth some more science when completed. And now I can't take any more contracts, and must hurry up with this landing.

In retrospect, it will be shown to be a terrible idea.

It's been quite a change of style. From managing ships weighting thousands of tons, and costing tens of millions, I'm reduced to flying some awful junk with punitive mass and parts limitations. Most troubling of all, I can't reload games; I am prone to taking risks and try dangerous stuff, that's been my main bane in my previous caveman attempt.

But I've adapted surprisingly fast. Already flying a ship without SAS feels natural, and I learned to avoid any dangerous manuever with my manned ships.

Edited by king of nowhere
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Part 3: the first landings

Landing the first time on Mun and Minmus

Spoiler

We choose to go to Mun in this decade, with this limited technology and preparation, because we underestimated the difficulty of the task

Now that I can throw light, disposable probes at the problem, landing on the moons of Kerbin will be within my grasp.

It would make sense to start with Minmus, because it requires less deltaV. However, there is a juicy contract asking me to explore Mun, and it pays 3 science points if I can land on it and return. And it expires in a few days... free science...

So I took it. But landing on Mun was a lot harder than planned.

First things first; if I have to go around Mun, I want some relays to keep control

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Those probes have a double function. First, they are relays. But second, they have some science instruments and a lot of electric charge. I can leave them in orbit in hybernation, and whenever I get a contract "return/trasmit science from the space around X", I can go to one of those probes, take a temperature reading, and transmit it to Kerbin. It's the fastest, safest way to farm money.

I started building a constellation. Then I found the juicy Mun landing contract, and took it. And then I realized I can't take any more contracts: I have a limit of 2, one is needed to keep the terrier engine unlocked, the other requires the Mun landing. So I stopped after only 3 satellites. And only one made it as far as Mun. Turns out, the stayputnik has terrible aerodinamics, and the rocket keep trying to flip. It still has enough deltaV to reach orbit even after flipping, but it's not efficient.

Now for the actual lander. Once in orbit, I want 3000 m/s. In a normal scenario, 2600 m/s would suffice, but the lack of manuever nodes makes manuevering inaccurate. Putting together a final stage with 3000 m/s is easy, and it's light enough; more or less 3 tons. Now I have 15 tons available to send this payload to orbit. I can make a two stage mechanism; second stage with a terrier, and lift it with a first stage with a reliant engine. Except that no, I cannot, because I lack reaction wheels. And they are too expensive to unlock.

Without reaction wheels, I have no control authority. But it's ok, I can still control the ship - with engine gimbaling. Turn on the engine at minimum thrust, use it to set the ship spinning slowly until it points in the right direction, then make the real ignition. It's actually a lot more efficient than it looks like, you lose less than 1 m/s every time you make a manuever. And when you're not manuevering, you don't need attitude control. This goes for the relay probes too, and they work just fine.

But the reliant engine does not have gimbaling. Without control authority, and with the kind of awful drag the stayputnik generates in front - really, it's crazy - the rocket will quickly spin out of control, and I have to manually adjust it constantly. There's no way it can be lifted with a reliant. So I'm forced to use a swivel. But the swivel is heavier and doesn't have enough sea level thrust to lift 18 tons.

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First failed Mun lander

So I had to complement it with some lateral boosters. But boosters are a lot less efficient than LFO engines. Factor in the terrible aerodinamic losses, and I can't get enough deltaV for a return trip. Not even close.

After crashing three or four of those rockets, I realized I was running out of funds, so I took the save out, imported it into another profile, and did more experimenting there. I also wanted to make sure that space stage can actually land on Mun without reaction wheels - keeping it pointed correctly is a real chore, but feasible.

To make things more efficient, I took out an old idea I used long ago: instead of a normal staging mechanism, drop tanks from the top of the rocket.

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Second failed Mun lander

The advantage is that, instead of needing 2 terriers, I can use a single terrier. I deemed the manuever too risky to try in a no-save career, but this is an unmanned probe, I can risk. I also gave up on full science returns, I removed the heavy science jr and the experiment storage unit than came with it (the science jr is too fragile to survive reentry, and too big to fit in the cargo bay. The experiment storage unit can collect the data from the material bay and keep it safe for return). I can't afford those 250 kg, nor the 2 parts.

Anyway, this came a lot closer to the target, but still it's missing a few hundred m/s.

Note: the second attempt has radial decouplers. I had 30 science left, when I ported the save I tried to see if by unlocking those decouplers I could actually tackle the problems. But it didn't help enough, and later I managed to make the rocket work without needing them. So, when I went back to the actual career, I did not unlock those parts. And this explains why, later, I'll post a screenshot of the tech tree with the stability tech still not researched

The breakthrough came when I figured out that, by doing something counterintuitive, I could kill two birds with a stone. So I put a (empty) crew pod on top of the rocket

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The successful Mun lander

The whole point of using a probe was to avoid the heavy crew cabin. And now I put it back again? May as well do a manned mission - and no, I don't have the deltaV to safely do that. But the (empty) crew pod has reaction wheels. Their control authority allows me to use the more powerful - and lighter - reliant engine, removing the need for the inefficient boosters.

Equally important - what actually convinced me to do it - the rocket was having huge aerodinamic losses for its flat top. After detaching the boosters, even though the sviwel had twr over 1.5, at 300 m/s the rocket stopped accelerating entirely. All that thrust was eaten by drag. The crew cabin is a lot more aerodinamic.

And after consuming the first stage, I can drop it. So I can still have a light, 3-ton probe.

I was ready to return to the regular career and launch this thing.

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The first stage. The reliant still is insufficient for 18 tons - TWR around 1.2 - so it consumed most of its fuel just to pick up speed

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Second stage. The terrier also has low thrust for this task.

The launch profile is mostly vertical, both to ensure that the terrier will be in near vacuum when it starts, and because this rocket is still draggy, and hard to control in atmosphere. Still, with later launches I learned that I could make a bit more of a gravity turn.

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At 30 km drag is no longer a problem, jettisoning the crew pod

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Now a lot lighter, the second stage keeps going

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In space, jettisoning the spent drop tanks. In later launches I learned to squeeze some more deltaV out of the initial stages

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And the probe has finished circularizing, and it's still got 3000 m/s! Just as required

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Eyeballing the Mun transfer. Luckily Mun is big, it's easy to hit

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Straight on target. But I'd land on the dark side, where I'd lose contact

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So I turned the probe to the side and spent some deltaV to ensure a landing on the Kerbin side

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No need to circularize, I'll go for a direct landing. With high thrust I could have waited a bit longer to start the suicide burn, but in a no save career I won't take risks

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I got lucky and found some flat ground, will it stay upright?

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YES! Landing successful! With 1100 m/s left

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In theory, 850 m/s should suffice to return from Mun surface to Kerbin. Without manuever node it was a lot less efficient, though, the probe almost didn't make it

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Finally, jettisoning the engine to prepare for atmospheric reentry

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I didn't actually test the reentry phase. I was expecting the cargo bay to shield the stayputnik, but the craft started spinning, and the probe core got destroyed. Remember, I have 0 control over this probe

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the parachute still activated, though, bringing something back

So I did got a goo experiment from Mun after all. But the game didn't consider that part as "returned from Mun". I suppose it wants a functional craft.

So, for the sake of the contract, I had to try again.

Figuring out how to survive the reentry was trivial. In hindsight, it was a rookie mistake. Here I have a perfectly serviceable return vehicle, with a rocket on one side and a draggy stayputnik and cargo bay on the other. It will keep the delicate stuff in the back by itself. By dropping the rocket part, I instead got a smaller vehicle with a draggy stayputnik and a draggy cargo bay, and it starts tumbling. All I had to do was not drop the spent rocket. On the plus side, I could remove one part from the rocket.

Second lander was sent up. Landed on a slope. For several tense seconds, it spinned precariously on a single landing leg. Then it tilted. I reignitied the engine, but at this point the rocket was spinning a lot. After a couple more aborted landings, I saw I wouldn't have enough fuel left to return to Kerbin anyway, and I let the thing die. Well, can't always be lucky.

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Though the intact core and cargo bay could at least transmit a science experiment before the end

The third lander made it as far as the Mun flyby. Once out of time warp, it wasn't responding to commands. I forgot to hybernate the probe core, and it had drained the battery completely.

The fourth lander hit another slope, and it folded softly on the ground. But it was still intact, and with nothing to lose I tried something desperate

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The fourth lander, seemingly dead

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Skidding on the ground!

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Until the rocket is fast enough to upturn itself. Or until it explodes, whichever would happen first

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Got to orbit with 340 m/s. I don't have much extra, I must get the return burn right at the first try

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I did. Almost perfect, only need an additional 40 km periapsis lowering

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This lander made it back with 40 m/s. And indeed, without decoupling, it flies straight

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The landing legs burned in the atmosphere, as intended. It reduces drag in front, making the rocket even more stable

With the science I got, I unlocked Advanced Rocketry. Not much for the engines, but for the bigger fuel tanks. Part count was a big deal, swapping out two small tanks for a larger tanks fixes most of it.

For a while I gather some more money. The relay sats are doing their jobs giving funds almost for free. I rarely get those contracts, though, I keep getting "return science from the surface of Mun". So I sent a modified lander there, without any of the trappings needed to return - without even landing legs, it can rest on the ground and I can put in three more batteries - just to transmit science from the surface. And guess what, now that it's in place, I get a lot less of those contracts. I also did drive more rollers around the ksc to get ground science - those contracts take some minutes to complete, but they are worth over 10000 funds. And I sent some missions to collect missing science, but without much success; the science jr tends to explode on landing far too often for comfort.

Finally, it was time to land on Minmus. Landing on Minmus is a lot easier than on Mun, but I want to use a crewed capsule, and to bring a science jr, to get the full science return. Ideally, I'd like to land on Minmus 9 times, get all the biomes, and then forget about the place entirely.

With the additional weight, landing on Minmus is not easy. First, I get another test contract to gain the spark engine; it saves some mass on the final stage. But then the rocket is wobbly, leading to inefficiency. And the reliant is barely fit to lift the first stage; it has a twr of 1.18, and gravity losses are huge. Attempts to use two thuds instead were also unsuccessful. Once more, I need another test engine, the bobcat, to increase efficiency on the first stage and get enough deltaV.

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The Minmus lander

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Second stage, inserting into orbit

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I sent two separate capsules, on two different trajectories, to increase chances to hit Minmus at least once

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Once more, both capsules missed, and I again have to resort to pointing the ship in the general direction of Minmus and burn

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Both Jeb and Val made it to Minmus, after extensive manuevering

Having a crew, I have once more to think of safety. In theory I only need 150 m/s to return to Kerbin from Minmus orbit, but I decided I want at least twice as much to make up for any inconvenience. This requires that a lander in low Minmus orbit has at least 700 m/s to attempt landing. Jeb didn't, but Val had a better Kerbin ascent, a bit more fuel left, and she could land

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Val landing on Minmus

Jeb wasn't useless, though. First, his science jr could be used to get some orbital science. And second, I got a contract (one of the cushy ones rewarding with science) asking for a rendez-vous in Minmus orbit, and with the landing aborted Jeb had a few hundred m/s to spare for the task.

Then both pods made it back, with some 200 m/s leftover. Jeb got close enough to Mun to be blown off course, but it only took a small correction to fix that.

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A nice pic of a landing in the mountains

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And my current tech tree

Landing on Minmus gave 32 science from experiments, so I'm going to get an additional 250 from the other biomes. Next thing to unlock is the docking port, with that I'll be able to land a crew on Mun.

Now the real grinding starts. I have to make a lot more Minmus landings.

 

Edited by king of nowhere
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Posted (edited)

Part 4: an end, and a beginning

Getting all the Minmus biomes. Val is lost in an accident, Liliana takes her place

Spoiler

Jeb and Val weren't done with their debriefing yet, that the engineering team was already trying to improve the Minmus landers.

First, it was realized they didn't need a spark engine. Sure, a spark engine is lighter than a terrier, but no engine is even more light. So I removed the spark and used a staging mechanism expelling tanks from the top, like I did for the Mun probes. Put some more fuel in its place, so the overall performance is increased. Also, more thrust during landing is always welcome.

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The improved Minmus lander

Removing the narrow point was supposed to also fix the wobbling problem, but it didn't. So I realized, it's not a problem with the rocket, just with the engine; the bobcat is very powerful, when it tries to turn it just twists the rocket. So, I limited rocket gimbaling to 25%, and it doesn't wobble anymore.

As the science from Minmus kept coming, I did unlock Miniaturization, allowing the use of the small stage separator between the crew pod and the upper tanks, and Electrics, whence I put a solar panel in place of the battery.

Meanwhile, I didn't need the spark engine anymore, so I went to fulfill the contract to test it. And here, in the least suspecting circumstance, tragedy struck.

The contract required to test the spark in very specific circumstances: high altitude and low speed. Those are the kind of conditions you'll never get in a real flight, unless you are making a suborbital jump specifically for it. So I went and did exactly that. And since I was missing some science jr experiments, I strapped them on the rocket and tried to land on the cursed mountains west of the ksc. The mountains where I tried to land a science jr many times, without success.

First part of the mission was fine. Rocket went up, tested the spark. But during reentry, the crew pod flipped.

No panic, it's not the first time a kerbal survived that. Open the cargo bay, it will slow down the pod enough to open the parachute. This should be even safer than regular pods, because I took advantage of the low mission requirements to put in an additional parabrake. Parabrakes should open in harsher conditions than parachutes, and be a further insurance against accidents.

Well, neither the parachute nor the parabrake opened. Don't know why. The pod didn't even fall that high up to call thin atmosphere into account: it slammed into foothills at 1100 m altitude (yes, to add insult to injury, not only I lost a pilot trying to land a whole science jr on mountains, I didn't even hit the biome).

Of course, during the event I was too busy trying to do something, so there are no screenshots. The best I could take was the report on Valentina's death

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The report on Val death

For a moment I was very tempted to cheat. But I still have 3 kerbals left. And then I can hire others.

Right, I can hire others. This is not the no contract challenge, this is the caveman challenge, I have basically unlimited money as long as I have patience. I have unlocked solar panels and the okto probe core, which comes with (very weak) reaction wheels.  I updated my relay fleet, putting a probe with antennas and a thermometer in Kerbin, Mun and Minmus orbit. I took advantage of contracts asking that to even get paid! Then I landed other similar probes on Mun and Minmus. Now I can complete easily any contract of "get science from X location", in a completely free and renewable manner. I have officially unlocked infinite money.

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On the right, the orbital relay with the science instrument. The probe on the left will land on Minmus to provide a fixed science base. An identical probe went to Mun

At some point, to my surprise, I even see a regular contract offering science reward! Those weren't supposed to happen in nanodiamond level

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This contract to place a satellite in retrograde orbit offers 1 science as reward

It starts dawning on me that I will really win this challenge, no matter the lack of saved games, no matter how badly I can screw up. I can make infinite money and reputation with the probes I already have in place. With that money, I can take contracts granting science. I could technically finish the challenge already, without exploring further. Well, I could use the administration building to convert money into science, either.

But it's not in the spirit of the challenge, and it would not be fun. At this point I decide I'm not going to try to launch a kerbal stuck on a ladder to get eva reports all around and finish the challenge without ever leaving kerbin, either; I'll explore Mun, and finish with a big interplanetary mission, regardless of whatever else I could do.

Anyway, now I want to replace Val. I have 200k funds, and I need 520k. It took two or three hours. At first it was slower; I'd find a few contracts "return science from X place", but after a while they stopped, until I went and did something else. Then I figured maybe the game is designed to prevent the player from only picking one type of contract, and I should differentiate. So I started picking also "test stuff on the launchpad" contracts - even though they don't pay enough to be worth the time - and this seems to have worked, because now I keep getting "return science" too.

Maybe that's not in the spirit of the challenge, but it was already a very boring couple of hours. Actually fulfilling regular contracts would have taken 0 effort, it would have been extremely time consuming, and mind-numbingly boring. It would have entailed 0 risk (unmanned launches only), and would have been just as much interesting. No, thanks.

Finally, I had enough to hire another female pilot.

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Welcome to the rooster, Liliana

I hired her before the final two Minmus landing, because I wanted to give her a landing (for XP), and I wanted to make a docking and crew transfer with her and Jeb in Minmus orbit (for a contract).

Meanwhile, I got better at hitting Minmus. I realized, instead of shooting wildly in roughly the right direction and hope, it would be better to treat it as a rendez-vous. Minmus is overtaking my pod? Raise periapsis, get slightly lower than Minmus, wait to overtake it.

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A couple of very successful Minmus insertions

As a result, I started having additional fuel left. Not that I could do much with it; I could jump to a different biome, but the science jr cannot be refreshed anyway. Though it did help the time my biome map turned out to be inaccurate.

Since I had free deltaV that would be discarded anyway, I tried to do something nice by taking some Minmus exploration contracts. Those tend to pay very well, and are easy enough with suborbital jump. There I made the mistake of picking up a contract that would spawn multiple targets in a close area. I run out of fuel after two, and needed two more.

I laid the rocket on the ground and used it as a roller. It worked.

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The Minmus lander used as a roller

And so, all Minmus biomes were explored easily. Finally I won't have to shoot in the dark anymore. I used the additional tech to also get Heavy Rocketry; the bobcat engine is fundamental for efficient launches, I want it unlocked for good

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Tech tree at this point

Edited by king of nowhere
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Part 5: if you believe, they put a kerbal on Mun

First manned Mun landing

Spoiler

Actually, I've done this part in the middle of the previous one, because - once more - a contract offered science for it. But narratively, it fits in a separate chapter.

So, need a Mun lander. A single launch to Mun with a level 1 launchpad is feasible - indeed, I've done it for an old challenge - but it doesn't leave any safety margin. A Mun landing is nominally slightly more than 5000 m/s from Kerbin, but with the perspective of inefficient injection and being unable to reload, I want at least 6000. The Minmus lander is already pretty well optimized, and I can't do much better, and it's not even close to 6000. But the Minmus lander would make for an excellent descent and ascent vehicle, and it conveniently reaches LKO fully fueled atop its launch vehicle. So I keep it as the base, and dock it to a space tug for the Mun transfer.

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The Mun lander pod; basically a Minmus lander modified to have a larger base

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Here docking with the space tug; basically a glorified fuel tank with a probe core on it.

I'm sorry those designs can't be as beautiful as my grand tour megaships

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The tug does the orbital manuevering up to Mun, with its own fuel

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And leaves the pod in low munar orbit. It's mostly spent now

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I came in perfectly equatorial, so I went for the canyon

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Perfect landing

Now I'll have to start mining the 17 Mun biomes for science too...

 

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Part 6: Just to show that I can

I decide that I will not try to finish the challenge by launching a kerbal on a ladder and collecting EVA reports.

However, I still land on Mun a kerbal on a ladder, to make a point that I could have completed the challenge thusly, had I wanted.

Spoiler

With the reliable capability to make manned Mun landings, I should be able to finish this challenge handily. That won't do.

Gathering all science from around Kerbin is an uninspired way to win. I want to run a full interplanetary missions, and I settle for a Jool 5. In part because it looks very difficult. In part because I'm actually a lot more worried about the perspective of pinpointing an interplanetary transfer blindly than I am at the idea of planning yet another Jool 5.

I also decided I won't use EVA construction, because for a long while people have been making caveman challenges without this resource. EVA construction makes the game a lot easier.

So here are the additional rules I gave myself for this challenge:

- No EVA construction

- No sending a kerbal on a ladder to get EVA science - else I could finish caveman with just the Kerbin system

- Aim for a level 3 Jool 5: five different kerbals, one for each moon

- bring a full suite of science instruments to every surface

- put some beautification on the mothership

The "beautification" part refers to the fact that I want to give every kerbal his own personal hitchhicker container to live in. After one year playing with kerbalism, it just feels wrong to send a crew in a long mission without some extra luxury. So the first technology I unlock with the science from Mun landings is Space Exploration, for the hitchhicker container.

This tech also unlocks ladders, bringing in an additional challenge. So far I stated several times that I won't bring a kerbal around on a ladder. But I won't, or I can't? To show that it's a self-imposed restriction, I decide to bring a kerbal on Mun in EVA.

It was a lot harder than I anticipated.

The main problem is that a Kerbal on a ladder will face aerodinamic resistance and will be blown off of the ladder. Strong accelerations can break a kerbal loose also in vacuum. So I want to bring a kerbal inside a cargo bay, so that he's protected. So I took the Mun lander, moved stuff inside the cargo bay to make room for a ladder, and devised a vehicle to bring the kerbonaut there

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I'd have called it the Girapphe, but this is caveman, so I called it the Brontosaur instead

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The Brontosaur lines up with the rocket

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And delivers Liliana inside the cargo bay

Actually, it's a lot more complicated than that. It's very hard to grab the ladder, and very easy to make Liliana fall to the ground. She'll survive, of course - those little green men are made of iron - but then there's no way to bring her back to the cargo bay. No, I could not afford to put a ladder to let her climb, part count is the limit. And I kept changing the geometry of the Brontosaur and cargo bay to try and make it easier to enter.

Here I went to the alternate career where I test things without fear. Mostly because I could use Alt-f12 to move the Brontosaur instantly from the runway to the launchpad without losing time driving the 2 km distance.

Anyway, the cargo bay is slightly smaller than a kerbal's comically-oversized helmet, and this creates some clipping problems. Since I was in test mode, I decided to check what would happen if I remove the helmet to avoid the clipping. Yes, the kerbal dies during launch, of course. But not for lack of air: for overheating.

Which brings to the second, worse problem. The kerbal in the cargo bay should be protected, but she isn't. She's taking full heat as if she was directly exposed to the outside. Which, more than anything, is an aerodinamic problem

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See that huge red arrow of drag? The one originating from the upper part of the rocket? That's Liliana inside the cargo bay. Notice the navball, how the rocket is twisting and turning around

By the way, the resistance value given by the aerodinamic overlay menu does not take that into account

Still, even though the rocket was difficult to control, the Mun lander pod has enough extra thrust and fuel that it did reach orbit easily. Though that fuel was supposed to be used for the Mun landing... But the main problem is, if the cargo bay does not protect during ascent, it's unlikely to protect during reentry either. Again, since I was in the test career, I tried it, and of course, Liliana died. Good thing there are no kerbal feminists.

I also discovered that a kerbal on a ladder inside the cargo bay - or stuck on a ladder in other awkward ways - will produce thrust. I guess I discovered what's the whole "kraken ladder engine" is about; put a kerbal on a ladder in a way that's microclipping into some other part, and the microclipping will shake the ship, producing some thrust.

Finally, I discovered that I cannot time warp with a kerbal on a ladder. Sure, you're not supposed to, but in the past I did do it by changing vehicles and time warping from the tracking station. Can't be done anymore, apparently.

I realized that the kerbal needs a dedicated launch vehicle. The lander pod doesn't have enough extra deltaV to deal with the huge drag. The kerbonaut can then latch to the ladder of the command pod, where it won't cause krakens. It will need another pod to get in before reentering atmosphere. And I will time warp with the kerbal detached from the ladder; it will slowly drift away, but a small push with the jetpack will suffice to return.

All this is the result of recent (1.8.1, I'm told) changes; in the past, it was a lot easier to send kerbals around on a ladder. Still, there's people who did a Jool 5 in caveman and did send Jeb all the way to Jool in EVA; and apparently they faced my same limitations - except that they did disable commnet, so they could get away with moving probes.

Anyway, for the actual mission I used Bob.

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I devised this way of putting the kerbal in the crew pod. It's a lot more efficient than the Brontosaur

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The truss, of course, gets jettisoned before launch

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Bob in the cargo bay experiencing extra drag. But this time the ship is only meant to carry him to orbit, it's got a lot of extra juice

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Once in orbit, Bob lets go of the crew transport, to avoid kraken drive issues

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And he rendez-vous with a fully assembled Mun lander, prepared previously

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The Mun lander goes to Mun. Thrust is not too much, and Bob can stay on the ladder easily. After the transfer burn, Bob leaves the ladder and floats

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Arriving on Mun, straight on target. Bob only drifted 1600 m from the craft. He's got plenty of eva propellant still to return on the ladder

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Circularized around Mun, and left the transfer stage in orbit. The lander is much smaller, and can get a lot more acceleration. To avoid kicking Bob free of the ladder, I reduce the thrust to 30%

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Landed on Mun. A bit more expensive for the lower thrust, but no issues

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Back to orbit. I can't aerobrake, so I rejoin the transfer stage to recover its fuel and rocket brake around Kerbin

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Here the transfer stage was spent and jettisoned, the lander was mostly spent, the orbit was lowered to 180 km apoapsis. Now Bob leaves the lander

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And the crew transport, which brought Bob in orbit, comes back to grab him and deorbit

In this, I took advantage of Bob's ability to refresh the science jr to get more measures in orbit without a dedicated mission. I pointedly did not collect eva reports, except for one on the surface, just to leave it on the record.

Now it's time to start planning the Jool 5 mission

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Posted (edited)

Part 7: it's not a King of Nowhere's mission without some massive mothership!

Preparing for the Jool 5, I begin assembly of the Navis Sideralis Neanderthalensis

Spoiler

Back when I was playing the no contract career challenge, I did end up assembling a large mothership for a Jool 5 (actually, it came close enough to a grand tour) with the limitations of a level 1 VAB and level 2 launchpad.

Now I will have to do the same, but with a level 1 launchpad too.

Also, can't transfer fuel between tanks, so I can't send up a lander and refill it; all fuel tanks must be detachable. Can't use autostruts. And a bunch of other limitations.

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Tech tree for the task; I've also researched Propulsion Systems and Flight Control. I've landed on 9 Mun biomes, I can afford to get a couple more tech if needed

As usual, I must name the ship. Being a caveman challenge, I want to stick "neanderthal" somewhere.  I decide to call it neanderthal spaceship, but in latin, so that it sounds like the name of an extinct specimen. So I looked up "spaceship" in latin... What? Yes, of course there is a latin expression for spaceship. Latin is the official language of the church, they've been updating it. There is a whole list of modern words translated in latin.

So here it is: Navis Sideralis Neandethalensis.

The core of it all is going to be a bunch of 5 hitchhicker containers, that will be the living quarters. To them I'll strap the main engines. Then the drop tanks. Landers and other bits and odds stuck around hapazardly.

With the launchpad limitations, I was able to send 4 tons in orbit on a single launch. The hitchhicker container is only 2 and a half tons, and I wasn't expecting to have many problems launching it, even though it's aerodinamic problems incarnate.

After some rough calculations, I decide I want 1 cheetah engine in the central core, and 4 poodles in the lateral ones - detachable, to save weight after I discard most of the drop tanks. The cheetah, of course, comes from another test contract

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Navis Sideralis Neanderthalensis, core stage

The core stage, which also includes a probe core and some antennas (no, I don't know why I put them since Jool is way too far), barely made it to orbit. Aerodinamics is terrible.

The lateral modules have an additional docking port between the engine and the crew. Which exhacerbates aerodinamic problems. I tried a half dozen launches, but it always falls short of orbit. It may have been smarter to just change design, but I grew fond of this concept. So I set to strap on additional fuel tanks on the launchpads. I keep using the cheetah engine, it's very useful for my needs here.

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The core launcher for the additional 4 crew cabins. With the docking ports in the bottom for the strap on tanks

This thing's aerodinamics are so ugly, the launch profile entails flying perfectly straight up until 200 m/s, then throttling down and going like that all the way until the first stage runs out. A launch profile normally reserved for Eve. In this configuration the first stage runs out around 9-10 km altitude, the cheetah is already fairly effective but there's still too much drag. With the extra tanks the first stage can last to 15-20 km

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And the tanker to load four more tons of fuel in the first stage

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The tanker goes to the launchpad. That black line is a terrain glitch that will break your wheels if you're not careful

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Docking the fuel tanks

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Unfortunately, docking stuff on the ground tend to cause microclipping issue. In this case, they scrambled my poor rocket badly, tilting the point

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The rocket starts flying askew. To try and save it, I pull up the engine gimbaling (it's normally set at 25%) to steer the rocket upwards

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Ascent was a lot inefficient, but I at least managed to not flip the rocket and keep it pointed vaguely upwards. At 15 km the first stage runs out, the second stage tries to restore an equatorial profile

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The second stage barely managed to reach orbit, it run out of fuel during rendez-vous manuevers. I rescued it with a Mun transfer stage (which was later recycled for a Mun landing)

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The transfer stage brings the crew pod to the growing spaceship.

The core stage, the one with less aerodinamic problems, I got it flying at the second or third attempt, in regular career. The other modules, after blowing up a couple of them, I went back to the test career to get the whole tanker mechanism right. I went then back to the caveman, and I lost one of them. The second, for which I showed the gallery, was the most adventurous launch. Another launch tilted too much and was lost in the ocean, the others went with less drama - though all of them had some hiccups.

In the end I also sent the Service Probe. It's a constant fixture of my motherships, but here it will be specially needed to move around all tanks. I can't refuel my landers, swapping tanks will be needed.

I was about to launch two, but then I remembered this is not kerbalism, there's no risk of one breaking up. I launched it last because, before the last launch, I was still missing a crucial tech node.

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The Service Probe in front of the station

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The service probe helping with improving the alignment of the modules. Yes, I had to undock and re-dock most of them many times to get them properly aligned

The Service Probe includes an additional fuel tank for itself. But the flight got wrong, tilted the rocket too much and it started flipping, couldn't recover it until it was at 20 km height. At least I managed to shut down the engine when it was pointing downwards, and turn it on again when it was pointing upwards, and so I could save the probe - but I had to spend all the fuel in the extra canister to compensate for the awful launch.

Too bad I didn't think to take screenshots while there.

That's it for now. Navis Sideralis Neanderthalensis will keep growing. It's currently at 15 tons. Estimating 50-60 tons of payload for the landers, and calculating very generous amounts of fuel for interplanetary transfers in the blind, I want some 300 tons of fuel. It will take some time.

 

I read some stuff in another thread that gave me the doubt that maybe testing stuff in an alternate career like I've done may be disallowed. I asked the challenge keepers for legality (I already asked about it earlier, but I got a partial answer and I took it as an ok). I'll see if I can test properly the landers, or if I am supposed to eyeball them. Meanwhile, I'll send up fuel tanks, those require no testing.

 

Edited by king of nowhere
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Part 8: ad memoriam (and updates)

I make a memorial for Valentina. Meanwhile, construction of the Navis Sideralis Neanderthalensis proceeds and a fifth kerbonaut is hired.

Spoiler

Ever since Val crashed, I've been wanting to leave some kind of memorial. I finally decided on it. So I built a statue; for its pose, I called it the Valentina redentora

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Here is Val (well, as much of a likeness as I could do with those parts) standing in front of the mountains, arms outstretched, palms pointing upwards to the sky, urging kerbalkind to claim the stars

Val died while trying to land with a science jr on a mountain biome, so I figured using a science jr as the base and placing it on the mountains was fitting.

I would have liked to carry her on top of a mountain. But the rover I used to carry the monument was very crappy, limited by part count and the awkward payload

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This thing has very few solar panels. Even on flat terrain, winning air drag consumes more energy than it's produced. To send this contraption to the mountains west of the KSC, I neeed 4 days of brief traveling and long waiting to recharge the battery. It could move uphill pretty well thanks to its many wheels, except that it would drain the battery in 20 seconds. So, I just left the memorial as soon as I got into mountains.

 

The plan for a Jool 5 level 2 requires hiring another kerbal. Farming money is extremely boring, but I hit a good pace with doing a flight, mining 50k money, and flying again. This way I could slowly hoard enough to hire another kerbal. Say welcome to Quidatta!

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Quidatta has an excellent curriculum with a lot of bravery and very little stupidity. An excellent addition for the kerbal space program

I wanted to get a level 3 pilot to track manuevers, it's a lot more convenient than doing it manually, so I sent the newly hired Quidatta in solar orbit

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A 100Mm apoapsis is outside Kerbin's SOI, but it will entail very little speed compared to the planet

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Moving slowly compared to Kerbin ensures that I can return to it just by pointing the rocket in its direction and burning. Perfectly successful manuever, with enough fuel left to land on Minmus

Regarding the Navis Sideralis Neanderthalensis (NSN for short), I developed the ecape pods. They are not a luxury; they could save a lot of weight on the return trip if I don't make it with the whole ship.

By tradition, I call escape pods "Dolphin". But this is caveman, so I googled up the evolutionary history of dolphins and picked one of its prehistoric ancestors. So I named the pods Cetotherium.

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Cetotherium with launcher

The Cetotherium uses the Pea pod because it's the only 2-person pod I have available. It uses two thermal shields, because last time heat transfer from shield to pod was almost killing my ship, and I don't want to risk it. By the way, getting a test contract to access the 1.875 m thermal shield was a nightmare, it took hours, and I only got one after I finally gave up and assumed it was impossible to get such a test contract.

The Cetotherium, with its heavy thermal shield and its fuel reserve, is rather heavy, and has awful aerodinamics. Just like everything else I'm launching for the NSN, really. To get it to orbit, I had to use six extra drop tanks, delivered by the fuel shuttle

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The second stage is powered by a poodle engine. It's attached with a docking port because I want to also recover the engine

I was surprised by how powerful the poodle is. I got used to launching the kind of ships that required dozens of wolfhounds and still had low thrust. It gives some perspective to how incredibly huge were my motherships.

Recovering the poodle and attacking it to the station was difficult. It required grabbing the free-floating engine with the service probe, aligning it perfectly with the docking port, giving it a push. Then turning around 180° so that the docking port of the engine is pointing in the right direction, undocking the service probe from the engine - which is now without control - and moving it away. Doing it too fast entails getting the service probe stuck on the docking port where the engine is supposed to go. Doing it too slow entails the engine drifting too much and missing the docking port. It took some trial and error, but I only have to do it twice.  Four times if I send the other two poodles the same way.

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Detaching Service Probe from the engine...

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And getting it out of the way so the engine can dock properly

In addition to the two Cetotheriums, carrying 2 people each, there is the command pod. That one is supposed to be docked to all the landers, and to also return to Kerbin - this way, I'll get the "return from the surface of X" bonus. It also has the science container to grab all the science and return it.

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Navis Sideralis Neanderthalensis so far

In the above picture, it's the one in the middle. The long fuel tanks on it are the reserve fuel for the Service Probe - which already ate a full canister going back and forth tugging extra modules who ran out of their own fuel to a rendez-vous.

The ship is 31 tons at this point, and it's already starting to experience the first stability problems. If it gets much worse, I may have to reevaluate the "no eva construction" clause, and use it to add struts everywhere.

 

Edited by king of nowhere
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Part 9: the price of science

Navis Sideralis Neanderthalensis gets its supply of science jr and goo containers

Spoiler

So many things to add to NSN, in no particular order. Here I am sending up the last two poodles. I realize there is no chance to have a probe control point with my technology, so I also send an additional command pod to stick to the service probe, it will be needed when too far from Kerbin for remote control. The poodles are quite heavy, so extra tanks are used. I take the chance to send up Bob; being a crewed mission, I add a parachute for safety in case the launch fails.

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The launch was about to fail - those poodles aren't just heavy, they are also aerodinamically challenging. The problem is that all is stuck together with size 0.5 docking ports, because they are the only ones I have, and the rocket keeps changing diameters, which of course is bad. This launcher was about to fail, but I could rescue it by jettisoning a poodle. A second launch sent up the last poodle - and a new crew pod, because I realized this one is lacking a docking port.

Then I send up the expendable science. I want to mine science from everywhere I go, and unfortunately science jr and goo containers cannot be restored with caveman limitations. This means sending up one for each measure. I will land on 5 moonss, for each of them I'll take a reading on ground, low space, high space, so 15. Plus there is Laythe's low and high atmosphere, and Jool low and high space, total 19. For a moment I consider adding a skim on Jool's upper atmosphere; it would be feasible, but I'm not in the mood for it.

Sending up the science containers turns out to be extremely challenging, as they make a ludicrous amount of drag. Also, they have high part count, leaving few for the actual rocket. After the first flipped and exploded already at low speed, I went and tested. I had at least half a dozen failed launches of the 5-container rocket before accepting it would be easier to launch 4 science containers in five different launches

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Those things flex and flip so easily. Removing the front fuel tank helped only marginally

The payload mass is very small, and even the aerodinamic gain is not easily noticeable. But the major gain of using 4 science containers instead of 5 is that it frees up 4 parts. With them, I could afford extra fuel tanks and a reaction wheel.

With the extra fuel, I tackled this aerodinamically challenging launch by brute force: fly straight up until 150 m/s, then throttle down, and keep flying straight up at 150 m/s until you're well above 15 km. Horrible gravity drag, but I have the extra deltaV to make up for it. The second stage alone has 2800 m/s vacuum, it can reach orbit alone after the first stage cleared the atmosphere. Even this way, three launches out of 5 flipped. But the rocket has enough extra deltaV that it can reach orbit regardless.

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The science canisters about to be docked to NSN

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Current status of NSN: 50 tons, of which 15 fuel, and 231 parts so far

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And a schematic breakdown of the budding mothership

As it is, the station can turn around easily. But if I try to hold it still with SAS, it will start wobbling. I did not try to discover what happens if I let the wobble build up; deactivating SAS and time warping is enough to stabilize the station, and without SAS it will stand still no problem. I'm still hoping I won't need to add struts everywhere.

Now I will start working on the landers; I expect to need 30 tons for a Tylo lander, 10 tons for a Laythe lander, 5 tons for Vall, and 5 tons for the last two moons. Then I will want at least 200 tons of fuel tanks, for an estimated 300 tons of additional mass - and no less than 300 additional parts - I need to launch.

 

Edited by king of nowhere
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Part 10: Landers ahoy!

Developing and launching the landers for Navis Sideralis Neanderthalensis

Being unable to transfer fuel poses some unique challenges, as fuel tanks have to be swapped every time. Launch mass limitation also forces a modular design

After reading another report where people consider cheating the testing of stuff in sandbox (the challenge rules only specify mods), I asked challenge keeper JAXO if I was fine. He told me to go ahead as I was, but I'm still uncertain on whether I was supposed to do it or not. So I decided I'll keep testing in sandbox, but I'll limit myself to tests I could conceivably run in the career. So, I'll test everything in the Kerbin system, and won't try the landers on Jool.

10.1) Tylo lander

Spoiler

Landing on Tylo is expensive. You need at least 4500 m/s, if you have high thrust and perform all manuevers perfectly. 5000 m/s is a good target for a normal mission. Being unable to save scum for a good trajectory and having to eyeball everything, I aim at 5500 m/s. I also want a very wide base, because I won't have the luxury of trying again if the lander flips on the ground. I can't launch a wide base with my limitations, this requires a central tank with docking ports on the side on which to attach lateral connector tanks.

It is possible to make very compact landers by reducing mass; people launching a kerbal on a seat have managed with around 1 ton of mass. But I can't do that either. I need to carry my lander pod, which includes the heat shield for its eventual reentry, and I have to carry science instruments.

My first creation had the tanks attached on top, with long tanks descending in columns to act as landing legs. It was quite peculiar (pity that I didn't take pics of it) but not very effective, it weighted 33 tons. Realizing a single poodle would be more effective than 4 terriers, I based a new model on that and eventually managed to fit my requirements in under 20 tons.

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Tylo lander, final model (almost)

The whole thing has a nominal deltaV of 5200 m/s vacuum, but it gets better because the science jr and goo can be discarded after landing and various spent tanks can also be discarded easily. First the lateral drop tanks are spent, for 1300 m/s. They get dropped just before the last part of the descent, granting maximum thrust to weight when it's needed most. After landing I can probably already discard the landing legs, too. The fuel for the poodle will last for the first part of the ascent, where a high thrust is important. Then the poodle is discarded, and a last stage with a spark engine will finish circularization. The whole thing for 18.5 tons, including the lander pod - which is already docked on the NSN - and the disposable science.

I tested this thing in sandbox mode around Kerbin. Mostly I wanted to make sure that its joints would survive some jolting. Tests performed included

- in space, thrusting at maximum power. The leg connectors and lateral drop tanks flex in a scary way, but nothing gets broken.

- on Kerbin, detaching the science jr. It falls down after inducing some oscillation with SAS, it can explode, but in five trials it never destroyed pieces of the lander. It could have been a funny accident

- on Kerbin, detaching the drop tanks and dropping the lander from 15 meters (deactivating physical easing). The lander slams on the ground at a bit over 10 m/s, testing a hard landing. Result, the landing legs flex very precariously, but they hold. However, the poodle comes into contact with the ground and explodes. I fixed it by moving down the docking ports, to get more clearance between the poodle and the ground.

First part to be launched is the core, comprising the poodle engine. Using a poodle engine for a 2-ton payload feels a waste, so I send up the whole central part, including the last stage with the spark engine. This way I also save on 2 docking ports to connect it to the poodle stage.

Of course, the launcher needed additional tanks for this - 4 of them, to be exact - but by now, adding fuel tanks is routine. I forgot to take pics of the launcher, though it was another one of those aerodinamic monsters meant to be launched slowly and vertically.

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Tylo lander, core stage, third stage of the launcher. Here with some drop tanks in front, though it already dropped more tanks

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It's quite uncomfortable to dock, because it had the probe core attached on its docking port. So to dock it has to expel its probe core and something else has to grab it like a piece of junk

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Here the Service Probe grabbed the lander pod and docked it to the Tylo lander

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The lander pod is then reattached to the NSN. I plan on landing at Tylo first anyway, may as well have the lander prepared

Then I take the other parts of the lander and launch them one by one. The side connectors, which include the drop tanks, weight around 3 tons each, and aerodinamic is not too bad. A comfortable launch

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Dropping tanks from the top of the rocket is a constant fixture in this challenge

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This launcher expelled the landing leg attachment due to a staging error. Whooops!

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This visual perspective is used during approach to try and align the lateral docking port pointing downwards, as precisely as possible

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The landing legs are light, I could launch all four in one go except for part count. Limited at 2, I use a simple, light rocket with luxuries like fins

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And I dock the first two landing legs

At this point I realize the mistake. The landing legs are not giving the poodle much clearance. But I specifically moved everything down to avoid the Poodle slamming on the ground on a hard landing. And then I saved the craft, and I took its parts when I made the various launchers... ah, crap, now I see what I did wrong.

I made the first model of the lander in the career. Then I opened it in sandbox, and tested it there. Then I saved the modified version, but it got saved in sandbox. And then I went back to the career, and opened the old model.

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The actual Tylo lander. Notice how the lateral docking ports and the landing legs were moved down, to give the Poodle additional clearance

After a couple hours of work, I will have to launch the lander again. Do I really have to? The lander will work just fine, as long as I slow down properly before touchdown.

Yes, and if my finger slip for half a second, I will crash the lander and lose after all this work. Better to spend some time to remake the lander.

On the plus side, I can recycle the side connectors.

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Moving the faulty tylo lander to a lateral docking port

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Using the service probe to transfer a side connector

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Attaching a landing leg, careful about alignment

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Finally, the Tylo lander is complete

With this inclusion, Navis Sideralis Neanderthalensis has 299 parts for 66.5 tons

 

And after writing all of this, I remember that my original idea was to use one of the poodle engines from the mothership for the lander. The plan had always been to drop a couple of poodles as I drop most fuel tanks, so I could have recycled one for this lander. But this time it's really not something to be worth making the lander again; I'll just load one extra fuel tank to make up for the extra mass.

10.2) Laythe lander

Spoiler

Landing on Laythe is a lot less expensive than on Tylo, but a lot more complex. On Tylo there is only the matter of deltaV and thrust; on Laythe you have to take care of the atmosphere during reentry, and you need to worry about whether you'll land on solid ground or water, and you need to factor in drag...

You can land a rocket or you can land a plane. So far, whenever I did land a rocket on Laythe, I used save scumming to make sure to hit an island. Of course, this won't be an option here, so a plane seems the better way. So the plan is, make a plane to land on water, take off from water, reach maximum altitude, then ditch the wings and keep going as rocket. My first spaceplane, the Not!Albatross (used in the Jool 5 science run), managed to take off from water on propeller power alone; how difficult can it be with jet engines?

As it turns out, a lot.

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Basic spaceplane model

This is my core model. It flies really well (and by that I mean, I intentionally tried to flip and stall it, and it never had a problem), it lands on water easily, and if I stick some wheels to it, it also takes off from the runway all right. The juno engines should be able to push the plane to around 15 km altitude, at which the terrier rocket can already work at full efficiency and make a low-angle ascent to orbit after the wings are jettisoned. Orbital velocity around Laythe is 2000 m/s, the rocket part of the plane has an extra 700 m/s which should be able to cover any remaining drag and inefficiency. This neat little flyer weights less than 7 tons, including the command pod

It only has one problem: it can't take off from water. The plane barely reaches 20 m/s before drag with water stops it. It would need at least three times as much speed to take off; even adding two more junos doesn't help. Here I try a lot of other options

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Floaters, to reduce drag with water. But the drag and thrust are now misaligned, and they create a torque that flips the plane nose-first into the water

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A flea booster, to give a strong push out of the water; but not even the 160 kN are enough to accelerate significantly; this plane sinks a lot

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Same boosters, but angled to force the nose upwards out of the water. Of course, once that happens, the nose will keep being pushed upwards, until it makes a full circle and crashes back in the water

Hours of experimenting, and the closes I came to getting out of the water was with a swivel engine - and the rocket-plane spiraled out of control and crashed soon after. So much for taking off from water. Not!Albatross was actually pretty well optimized for it, it had low drag, it floated a lot, it had very strong propellers and a lot of wings for its size, it had the center of mass way backwards to help turning the nose high; even then, it barely succeeded. There's no way I'll be able to replicate the feat on a plane made for maximum savings out of scrap recovered from the junkyard.

Change of plans! The jet engines let me move around; I can find an island to land on.

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Plane project, now with wheels for ground landing

I tested this model, took off from the runway, tried to land on the flat ground surrounding the ksc, exploded. The LY-01 is supposedly rated for 125 m/s impact speed, but it's actually very frail. Or maybe it's some of the other joints that break. Regardless, I've never been able to make reliable ground landings anywhere, but especially on Laythe, whose islands have a lot of cliffs. I always saved before landing, and though some planes were more reliable than others, I've never mastered the art. Not with Not!Albatross, not with Arrowhead, not with Craplane. If I run a no-reload mission, ground landings are not an option.

Still, there was one last option: land on sea (where I can always do it reliably) but close to a shore, use the jets to move on water over the shore, take off from dry land. Testing was successful, and I did consider it for maybe a couple minutes. But in hours of testing planes, I became aware of many other problems

- I'll need to bring down three science jr; there's no way to dock them without them burning up in the atmosphere

- the wheels will also burn, because all the models I have available have low thermal resistance

- taking off from the ground can still end up with a broken plane, if only I hit a bump in the road

- this plane requires a very long runway for the juno's slow acceleration, hard to find such a place on Laythe. It increases the chance of finding the aforementioned bump

- moving on water is extremely expensive, it took me 1000 m/s to move 500 m to the nearest beach; if I fail to pinpoint the landing, I have a serious risk of running out of fuel

- all this testing was done on Kerbin; planes are generally harder to fly on Laythe, the latest self-imposed rules forbid testing on Laythe, and I have no idea how to compare performance

All the above factors, added together, result in a big "screw this" for the idea of flying a plane on Laythe. In a normal mission with reloads and in situ testing I could certainly make the idea work, but in this case there are too many unknown, too many potential failures, too many risks.

It will be a rocket, then.

A rocket is going to be a lot heavier and less efficient than a plane; but hey, I was factoring in 30 tons for the Tylo lander and I got away with 18, I can spend some extra for Laythe and still be on budget.

To land on water and stay upright, a rocket needs some kind of floaters in its high portion. Those can act as additional drop tanks, they will be terrible aerodinamically, but they will be discarded soon, and they are practically free fuel. I can tie the parachutes there, so they won't weight the ship during ascent.

I start with a swivel because it has good performance at Laythe's sea level, but I eventually jettison it for a terrier. The rocket's main body can't be made any longer than this, or the floaters don't work anymore.

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Laythe lander project

Finally, this model has the added advantage of being very stable during reentry, the floaters also act as aerobrakes, and they keep the fragile science jr shielded. I tested a Kerbin reentry, and they didn't even start to overheat.

The rocket has the disadvantage that it cannot land on the ground; after considering some very impractical ideas to make it hybrid, I decided I'd just deorbit over DeGrasse sea, where there is half a planetary circumference without any island; I'll sink periapsis down enough to ensure I land in it.

Now for launching; the rocket is 10 tons heavy, even without the crew pod. Yet I must launch it as a whole piece; joints based on the small clamp-o-tron are terrible for aerodinamics.

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Trying to launch the Laythe lander in a single launch

Besides mass, the lander is also very draggy, with those floaters in front. Six additional tanks strapped to the booster won't be enough. So I devise a new modular sustem to strap on additional tanks

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The projected extra tanks, complete with engine

I modified the drop tanks, gave them an additional docking port on the back so that moar drop tanks could be latched on, and added a spark engine on the bottom because the bobcat does not have unlimited thrust.

Before putting in all the work to strap on a dozen boosters on this rocket, without even any guarantee that it would work, I had a spark of wisdom and went again to test in sandbox

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Sandbox test of the infernal contraption I considered to launch the Laythe lander

The launch fails. I tried a fourth line of tanks (for a total of 16 drop tanks), it still failed. Hard.

It was an easy decision then to remove the floaters and put them on later. The main body of the rocket is still heavy, but it's reasonably aerodinamic, and launching it was mostly a matter of using enough drop tanks.

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Laythe lander core launcher

This launch would barely be worth mentioning, except that I experimented an innovation; notice the probe core stuck on a lateral docking port.

Placing the probe core is always a problem in this career. It is a small part, and it must be removed after docking, so it will always leave a gap into a rocket's aerodinamic profile. To minimize this, I sometimes placed the probe core on the front docking port, where the rocket would already become narrow and there's nothing to be done. But having a probe core there prevents docking, so I have to rendez-vous with NSN, eject the probe core, go grab the part with the Service Probe, and perform a docking with the probe in front - the kind when I have to detach the probe and get it out of the way and hope that the part will fly straight without control - and those dockings are very difficult.

So instead I stick the probe core to a lateral docking port, so that it won't force a narrowing of the rocket, but it also won't be in the way of the frontal docking port. The two small fuel tanks on the other docking ports are there for balance.

And how is sticking three parts out from the front of your rocket an aerodinamic improvement?

This is a very smart question, one that I myself haven't been able to answer. But this model did fly straight, so it worked well enough.

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The Laythe lander core rendez-vous with NSN

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And docks to one of the free docking ports

Now the floaters. After a failed attempt to launch all three, I go to sleep, and while I sleep I am filled with worry.

The Laythe rocket has 4000 m/s deltaV, vacuum. In every stage it has TWR >1, Kerbin. Orbiting Laythe nominally takes 2900 m/s; even with an aerodinamically challenged lander, I should be good. Should I?

Back when I did the Bolt mission, I had similar problems with aerodinamics. In that case the lander was good, but it was struck by a bug. Whatever the reason, aerodinamics was a major problem, and made a sound lander fail. So I went back to check on that mission report - keeping those diaries is useful! - and what I read did not comfort me.

Quote

The Heavy Lander had 3400 m/s, yet it failed to reach orbit by at least 400 m/s

3800 m/s would have been barely enough to orbit. And it was launching from a few hundred meters of altitude too, I'm stuck at sea level! I also have an aerodinamically challenged launcher; if it is only slightly worse than the (kraken-struck) Heavy Lander, or if I perform a suboptimal ascent profile, then I won't be able to reach orbit. And, as I keep repeating, I can't take risks. Everything must work at the first try. An additional fear came from Kerbin testing; I failed to reach orbit by well over 500 m/s. Laythe requires 500 m/s less than Kerbin, if I fail Kerbin orbit by that much, it stands to reason I should fail at Laythe too. Aerodinamic data also worries me; MaxQ is reached around 10 km altitude, but drag remains high until well past 20 km. And Laythe actually has higher atmospheric pressure than Kerbin at those altitudes; at 20 km the pressure is twice that of Kerbin. So I'll get a lot of drag at a time when I'm using the weaker terrier engine.

I'm probably overreacting. I have 4000 m/s, I should be able to push through any aerodinamic inefficiency. But for good measure, I added an additional half a ton of fuel to each of the drop tanks. Plus an aerodinamic nose cone.

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Floater tank launcher

The floater tanks have a peculiar design, and I had to figure out something creative to dock them on the side; in particular, while the easier way is to stick a second docking port for the Service Probe to grab, I don't want to leave extra mass and draggy parts on the rocket. So I did develop this system; there is a cargo bay underneath the floater tank, which contains the probe core and two ant engines for orbital manuevers. The second docking port is there (in the image, covered by the open cargo bay). I grab this docking port with the Service Probe, dock the floater tank in place - I may even be able to do it with its own ant engines - and then I jettison the cargo bay, leaving the floater tank clean.

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Ejecting the second stage just before orbit, for once I won't have to clear junk manually. Activating the ants, which turn out to work even inside the cargo bay

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Trying to dock with the core stage of the lander. It's very crowded here

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Unfortunately, it's a matter of spacing, there's no room for docking

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So I stick the tanks whenever there is free space, for later assembly

I've never had a ship with so much stuff stuck hapazardly around it. Even the DREAM BIG didn't ever came close to this level of encumbrance. The original ship core, made by the five hitchhicker containers, had 17 docking ports, not counting those for the engines; yet I used them all, and then I docked stuff on top of the docked stuff!

Navis Sideralis Neanderthalensis is now at 353 parts, 79.5 tons. I have 12.5 tons of drop tanks, the rest is all material that must reach Jool. The remaining landers should be easy and light, but still, by my estimation - considering a large extra because I won't be able to make accurate manuevers - I'll need at least 400 tons of fuel tanks. I'll get to 1000 parts again! :o

10.3) Vall, Bop and Pol

Spoiler

The remaining moons don't require any special challenge. Vall is slightly bigger than Mun, a normal fuel tank with a normal engine is enough

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The Vall lander

The Vall lander only weights 3 tons without the common lander pod, and it includes a very generous amount of extra fuel.

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And its launcher

When the bad aerodinamics are factored in, 3 tons are the limit of what I can launch without extra tanks.

Notice the ant engine stuck laterally on the probe core. It's yet another experiment to make an easier docking without using the Service Probe; the docking port is aligned with that on NSN, the final push is given, then the probe core is detached (always the problem when putting the probe core on the front docking port) and the lateral engine helps moving it out of the way. I was too slow with it, though, and still had to chase the lander with the Service Probe.

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Final lander for Bop and Pol, with launcher

Landing on Bop and Pol is even easier. A single large fuel tank with a single spark engine already provided 1500 m/s and TWR 0.7 (Kerbin); both are more than enough to land on both moons. I could make an even smaller lander, but I don't see much point in saving half a ton. It's all fuel anyway, I'm sure it won't get wasted.

Since this piece was light, I also sent the last part I needed: the command pod for the taxi. After some effort at imagining how all the various parts will be docked, I decided it's better to leave an engine on it permanently. Drop tanks will be stuck on top of it, and the landers on top of the drop tanks.

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The Service Probe with its own manned module rejoining the station

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I just love to break down a complex ship into schematics

With this, NSN is at 369 parts, 85 tons. From now on, it's all drop tanks.

 

Edited by king of nowhere
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Part 11: Fuel for the fuel god!

Beginning the biggest part of the Navis Sideralis Neanderthalensis: the fuel tanks. Also, trying to tackle the strutting problem

Spoiler

NSN is loaded with everything it needs at Jool. Now the problem is bringing it there.

For a normal mission, 2000 m/s are enough to reach Jool. Jool is an easy target to reach, especially with the moons to provide free insertion by gravity assist. Unfortunately, I can't do any of that. Reaching Jool and its massive SoI shouldn't be too hard, but there's no way I can hit a gravity assist precisely - even a moon would be challenging! Worse, I am likely to end up in a very high periapsis, possibly with high inclination too. 2000 m/s are still a reasonable estimate for getting to Jool, but I may have to spend the same amount just to enter a stable orbit. Then I will need a fair amount of fuel to wander around the moons, and then more fuel to come back - though NSN will have greatly reduced mass by then.

All in all, I'll need a lot of deltaV.

It's virtually impossible to calculate exactly how much deltaV drop tanks are worth, but I have devised a reasonable approximation: calculating the tank mass as fuel with Isp=0. This way I can just use the rocket equation with the full mass of the ship, and then multiply the end result by 8/9. So NSN weights 70 tons without the fuel, if I load 400 tons of fuel I have 400+50(fuel tank mass)+70=520 tons, and I estimate ln(520/70)*3500*8/9=6200 m/s. Or, I could estimate very roughly that after attaining Jool orbit I may need 80 tons of fuel (not including that already in the landers), and so I want to reach Jool with a 160 ton ship. The estimate is based on 40 tons to bring around the landers, which themselves have 40 tons of mass, and 40 tons to return, with an NSN stripped to basic and reduced to less than 30 tons; it's probably an overestimation, but better to be safe. In that case, with 400 tons of fuel, I'd get ln(520/160)*3500*8/9=3700 m/s.

Well, either way, you understand that I decided on 400 tons of fuel as an amount that should suffice even under pessimistic estimates.

In my previous missions, 400 tons were pocket change for my motherships. But this time, I have a limitation of 18 tons on the launchpad. I may need well over 100 flights for this.

There are no particular requirements to drop tanks; they must have docking ports to be stuck to other drop tanks, they must have fuel, they must be droppable. However, the huge number I want to launch require some conditions:

- I want big tanks, to reduce part count

- I want to send as much fuel as possible on a single flight, to reduce the number of clamp-o-trons used

- I want them to be thick, because thick, short lines of drop tanks will have less structural problems than long, thin lines of drop tanks

Drop tanks will need to have a docking port on either side. On the rocket, a thin docking port interrupting the radial size is a big aerodinamic and stability problem, so I resolved to put docking ports on the sides, as shown in the picture

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Optimal location of docking ports

The biggest tank I have is the FL-T400. It's thin and narrow, so it could work very well with docking ports on the short side. I toyed with the idea of making a sandwhich-like structure with them

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Project of drop tanks

That drop tank setup would have been wonderful. Six tons of fuel, only 5 parts, and thin. Unfortunately, I couldn't launch that kind of payload; too heavy, too draggy. Using two tanks side by side would have created all kinds of symmetry problems, using two tanks linearly would have made them too long and cumbersome, with high chance that they would interfere with the engines, and using only one would not be worth it.

So I went back and did a more conservative model based on the Mk 1.5 size

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Drop tanks, actual launcher. It's funny that with a 18-tons mass limit I am routinely launhing 32-tons rockets

The actual drop tank section is made by the three FL-TX220 tanks and two adapters, for better aerodinamics during flight. Total fuel mass, 4900 kg. I have four binding points for tanks, I can get by with 20 of them on each one, for a total of 80. Of course, launching that payload still requires the maximum amount of lateral extra tanks I can bring. To reduce the amount of trips with the fuel tanker, I designed a new version with 3 tanks instead of two.

I did show in part 7 what can happen with docking on the ground, but I found a better way: get close, then undock the fuel tank, then cover the last meter or so until the clamp-o-trons stick.

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It's not a 100% failproof system, but it does have an almost 0 chance of ruining the rocket, which is the most important thing

A nuisance of launching with lateral drop tanks is that the game does not detach the docking ports on staging. So I must select them all manually and manually detach the tanks. I learned to open all the relevant docking ports preemptively, during flight I am too busy to go chase them

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Now I am ready to fly

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Starting TWR is low, the first couple of tanks are spent just to pick up some speed

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This rocket has decent aerodinamics, it can do a normal gravity turn

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The bobcat is jettisoned, the second stage is based on a cheetah (got a test contract for it, of course)

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Once more, spent tanks are jettisoned from the front

I want to spend a few words on this practice of jettisoning tanks from the front I'm using all the time in this challenge. In the real world, you never see it. The main reason for it is, in the real world drop tanks are a lot less convenient. In the real world, tanks have a fuel ratio of something like 50:1, so you gain very little in jettisoning them. Until you have a lot of spent tanks, and then you use normal staging. In KSP, tanks have a lot more dry mass, with a 8:1 ratio. So it becomes a lot more convenient to get rid of them one by one. Those two tanks are 500 kg of weight, plus 30 kg for the nose cone. Furthermore, in KSP rockets can turn around a lot faster in vacuum, so you can point the nose away from your trajectory before jettisoning; in real life, you need RCS and a lot of work for that. And finally, it would require fuel lines bypassing the payload, adding a lot of complexity. But in KSP dropping spent tanks in small batches is convenient; and then you can't stick them on the bottom, or you'd have to jettison the engine too; you can't put them on the sides, for aerodinamics. And so you put them on front.

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The drop tanks reach orbit with the last of its launcher fuel

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There, to further save weight, I drop the cheetah and use an ant engine for orbital manuever

Actually, I realized later that this is pointless. I have a 5-ton payload, so dropping 1 ton of engine does not make a huge difference; going from 355 s Isp to 315 s makes up most of it. I only gain, like, 8 m/s by pulling this stunt, so I'll remove the ant engine for the future. It is conveniently oriented for docking, though.

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Docking to NSN. The remains of the launcher are then jettisoned and deorbited

Testing things in sandbox - with proper decouplers and probes that can hold all directions - was a lot more efficient, I managed to dock with less than 50 m/s remaining. Sure, as long as the tanks are in orbit, I can send the Service Probe to grab them- I had to do it on the second flight - but it's time consuming, and it also eats up a lot of fuel from the probe; I also had to send up extra canisters for it afterwards. I'll need to improve the launcher.

Meanwhile, I also finally face another problem I've been postponing: structural stability. NSN wobbles worse than ever, and I finally decide I'll have to get struts; if not now, before the end.

So I make another Mun landing with Liliana, whom I left on the ground in case of need. Since it only took a little extra, I also sent her in solar orbit for level 3.

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Here the manuever to return to Kerbin

With the last batch of Mun science, I get General Construction.

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Here's how my tech tree looks at the moment

I have still 5 Mun biomes left, plus one missing the science jr and goo experiments, for a total of 134 science points still easily achievable. I can get one more tech if needed, probably two if I complete the exploration of Kerbin.

This got me struts. I sent Bill back on Kerbin, then I sent him up in a cargo bay (See part 6) to place struts. Then I discovered with struts unlocked, I can autostrut stuff, so the whole mission turned out a waste of time.

I also got a larger decoupler, improving aerodinamics and stability on the launcher.

After the last missions I wanted some extra deltaV, especially more thrust during liftoff. I further modified the drop tanks to include a couple of flea boosters. This is actually the first time I find a practical use for them outside of the first launch.

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New fuel tanker. Placing one tank in the bottom also improves a lot stability while driving, and makes docking easier

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New Drop Tanks launcher

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The fleas push it fast to 100 m/s. Afterwards, it's ok to have lower thrust

The modification earns a good 100-150 m/s, which make the difference between needing to call in a Service Probe at the slightest mistake, and being comfortable.

The launcher in its current configuration is a good, reliable vehicle. I launched 6 successfully and lost 2, which does not seem reliable at all, but both those I lost were for very stupid mistakes: the first got a clipping accident while loading the side tanks on the launchpad, bending the rocket and causing it to fly askew. It was an easily seen flaw, I did see it, and I decided to fly anyway. I should have recovered the rocket and start a new one. The second, I thought I could save fuel by dropping the cheetah too early; with an impressive TWR of 0.03, the ant engine wasn't enough to circularize before the drop tanks got back in the atmosphere.

So, the launcher is realible, unless I do something real stooopid.

A whole launch sequence takes from 40 to 60 minutes, depending on whether I have accidents on the fuel tanker, how close to NSN I get with the launch, and how much I get distracted doing other stuff. So I'm looking forward to 70 hours of work to load all the needed tanks on NSN. It will take approximately a month, maybe less.

at 520 tons, NSN won't have enough reaction wheels, so I want to include some in the drop tanks. Fortunately, the latest launcher iteration is good enough that I can add one wheel and it still reaches orbit, if less comfortably

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The drop tank version with the reaction wheel at the bottom

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Seen on the launcher, it showcases the aerodinamic problems it creates

The problem with adding a wheel is not in mass - the launcher itself had a wheel in the cargo bay, I just moved it. But, as you can see from the picture, putting the wheel someplace it would stay attached to the tanks creates aerodinamic problems. Or, I could have stuck it to a docking port on a side, which would have added mass and docking ports (and drag, anyway).

I'm planning to send one wheel for every three drop tanks, but I'll keep seeing how NSN turns around and will base my decisions on that; if it becomes sluggish, send up wheels.

Finally, NSN still wobbles badly, so I learned I could check autostrutting with the alt-f12 menu (it's not in the cheat section, so I assumed it to be fair game, just like the aerodinamic display I've shown in a few screenshots). The results are... troubling

UqYC930.png

There isn't a single autostrut in a useful place!

I would like autostruts to stabilize the weak and wobbly small docking ports, but there isn't a single one of those struts that's doing it. And apparently, strutting to grandparent or to root causes no effect at all.

I may need that EVA mission with manual struts after all.

This is probably the last update for a few weeks; I have to launch 74 more drop tanks, not much to report.

Navis Sideralis Neanderthalensis currently at 421 parts and 119.5 tons

Edited by king of nowhere
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Part 12: First fuel line completed

Completing the first of four long lines of drop tanks. Structural stability is both promising and disheartening at the same time.

Spoiler

A bit more tweaking, and I eventualy settled for the final version of my launch vehicle.

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Drop tanks launcher, final version

As I mentioned in the previous update, I realize the ant engine isn't giving any deltaV benefit, so at first I took it off. Then there was no more point in jettisoning the main engine without the probe core, so I changed the position of the probe core to allow jettisoning the last fuel tank from the front. Later, as the number of drop tanks increased and turning around Navis Sideralis Neanderthalensis for docking became ipossible for all the wobbling involved, I came to appreciate the usefulness of a small engine in line with the docking ports making docking easier, so I restored the ant engines, but in the new configuration - it's no longer supposed to be used after dropping the main engine in orbit, it's just there for the last part of docking, I never use it for more than 5 m/s. It's basically a simplified RCS system, because I have no RCS unlocked, and wouldn't have the part count to afford the monopropellant tank if I did.

The launch vehicle is now extremely reliable, with over 20 launches docked to NSN without problems - I only lost one because I forgot to fix staging after docking the lateral tanks. The version with the external reaction wheel is a lot less forgiving, I do have accidents with those, but I don't have to launch many of them. Accidents on the launchpad during lateral tanks assembly still happen -

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like this; that's what happens when I miss the right moment to decouple. And yes, the rocket went all the way down and went boom!

- but they merely cost a few lost minutes to recover the money and make a new rocket.

NSN has four bind points for drop tanks; at first I was building on all of them equally, but I soon decided I wanted to complete one first. Both to see how it would look, to judge the scale, and to make some structural stability check.

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NSN fuel line growing....

In the last week, I've been managing two to four drop tanks launched daily, unless real life really got in the way

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The fuel line is now the main feature of the ship, well visible from afar

Until finally, today, I stuck the twentieth tank on that line

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The long line of 20 fuel tanks

It was time to run some testing; can I turn the ship around without it exploding? I did import the save in the test career before doing this, I was very worried it could go wrong. The following video details the test; it's been sped to 4x to save the viewer some time.

In the first 35 seconds, I try to turn around the ship using SAS. You see what happened; the fuel line behaves more like a snake, it's crazy. However, nothing broke. At 35 seconds, I use time warp at the right moment to stop wobbling, and then I carefully manage to point the ship retrograde - the experiment was meant to see if I could point the ship in the correct direction for the Jool transfer manuever.

The next test will check whether I can accelerate NSN without the fuel lines wobbling in the way of the rockets, or without causing huge losses of deltaV in other way. But I can't run it right now, I will need another line for symmetry or NSN will just start spinning around.

In any case, I can sent some struts and place them manually if needed. I'd be happier if I can do without, though, for the whole "let's try to not use eva construction" self-imposed challenge.

NSN at 230 tons and 562 parts. 26 tanks sent up, 54 to go.

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Part 13: milestones and testing

The second line of drop tanks is also completed on Navis Sideralis Neanderthalensis. Fire test is performed; struts are needed, but they appear to be bugged. More workarounds will be needed.

Spoiler

Not much to report, just adding fuel tanks. This week I managed good progress. A couple of milestones are reached

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Milestone: over 260 tons

NSN is calculated to weight 520 tons completed, I am now officially over 50% ship assembly

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Milestone: 40 fuel tanks

With this, I have launched 50% of the fuel tanks. In a couple weeks, so I'll probably be done in another fortnight.

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Milestone: second fuel line completed

Two lines  completed, two to go. 34 tanks left. NSN is starting to lag considerably, but I'm used to the multiple minutes loading time of A'Tuin, this is only a handful of seconds on entering physical bubble. I considered doing some more Mun landings to unlock Fuel systems and use a single FL-TX440 tank instead of two smaller ones, saving 80 parts. I decided not to; as soon as NSN is done, I'll immediately launch for Jool, draining a lot of fuel and dropping many spent tanks, and part count will drop again. I'll lose more time doing the Mun landings.

Now that I have a symmetric ship, I can test whether it can work without struts. So I imported the save in the test career and...

Ok, it will need struts. Lots of them.

I did some more testing, just adding four struts to the lateral crew pods stabilizes the engines. The fuel lines are still scattering around randomly and making problems, though, so I will need periodic struts in the fuel tanks too.

A lot worrying, though, is the fact that such struts seem bugged. they disappear every time i load the ship anew - even just going to the tracking station and returning to NSN will turn the strut into a stub.

I will need more testing to figure out how to circumvent this problem

 

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Part 14: tanks and struts

A new design of fuel tanks is implemented. It is confirmed that struts are bugged, but it should not be an insurmontable problem.

Spoiler

In the previous update, I established that NSN falls apart rather spectacularly without struts. Now I also established that struts are bugged.

For you see, I place struts

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Like this; some of them make no sense, but they are for the sake of testing

And for a while they hold, and a fire test was promising. But as soon as I leave NSN, go to tracking station, and go back, I find this

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Struts have disappeared

So, autostruts don't work, and manual struts are bugged, and NSN can't work without struts. I face a moment of desperation. Did I spent the last three weeks building this big ship five tons at a time for nothing?

But I have another plan. I know the struts work. And I know, as long as I stay in physical range of NSN, that the struts will stay there. So I can place the struts just before going for Jool, and doing all the manuever immediately. Arrive at Jool, do the capture burn. Either park in a high orbit, or get captured around Pol, I'm still uncertain on which is better. I have to do all that in a single gaming session, without ever leaving control of Navis Sideralis Neanderthalensis. Then, once I am stable around Jool, I start sending around the shuttles, the struts will disappear, but for a while it won't matter, because NSN won't have to be moved around. And finally, when it's time to go back, the ship will be a lot lighter and smaller, and maybe everything will work. Or I can ditch NSN and return with the Cethoteriums alone - plus one engine and a few fuel tanks salvaged from the mothership.

Meanwhile, lag is becoming a bigger problem - though nothing compared to the titanic ships I run in kerbalism; I suppose keeping track of life support is extra hard for the cpu, because even though I am close to 800 parts - about as many as A'Tuin - there is only a few seconds lag when NSN comes into physical range.

Anyway, I've been wanting to make some flatter fuel tanks; with lower part count, capable of being stacked more closely, they'd be more stable. I finally committed to doing it.

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The new fuel tanks, with 100 kg more fuel and 2 less parts

Despite the additional weight, this fuel tank is launched easily. It is a bit harder to manuever, because the ant engine is more off-center and turning on the long side is more uncomfortable, but it's not a big deal.

The version with the external reaction wheel, though, that one was always more difficult to launch because it drags more. Those extra 100 kg payload are making a difference here, the smallest mistake will make the launch fail. So I removed a truss from the fuel tanker to load some an additional fuel tank on each booster tank.

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The booster heavy. At 35 tons, it's almost twice the mass and parts limit for the level 1 launchpad

While I'm there, I also take some time to actually assemble the Laythe lander. Last time I mentioned it, I could not dock the lateral float tanks because there was no space. But I could move the lander to a less encumbered docking port. I figured assembling it would be complex (it was, those tanks aren't that easy to dock with a good alignment), and so it's better to do it here, where I can still send up new stuff in an emergency, than doing it around Jool, with no probe control.

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The assembled Laythe lander, on the lower left corner

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And jettisoning the leftovers from the float tank launchers

That's all the new stuff I did. Aside from that, I kept launching two to four new tanks every day, slowly moving towards the goal of 80. I reached another milestone: 60 drop tanks, 75% of the work completed

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NSN with 60 drop tanks

The new fuel tanks are better, and if I could come back I would use them from the start. But no way I'm spending another two weeks launching fuel tanks just to get a slightly improved version; the old ones are still perfectly serviceable - and they do look better.

One more week, give or take, and NSN will be ready to launch.

 

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Part 15: Navis Sideralis Neanderthalensis, ready to launch

Navis Sideralis Neanderthalensis is finally completed and ready to start its mission!

Spoiler

Only 20 fuel tanks to go. I've spent almost one month sending up fuel tanks. But bit by bit, the finish line approaches.

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A particularly beautiful hue of the atmosphere, likely caused by some special position of the sun

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Just a nice picture of a fuel tank launch

And finally, the 80th fuel tank is launched! :rep::rep::rep::rep::rep::rep:

Meanwhile, i've been somewhat careless in some deorbiting manuevers, the engine exhausts has hit the fuel tanks, and the tank lines got tangled up

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NSN completed. 851 parts and 532 tons, all launched and assembled in caveman

In particular, the fuel line on the right of the image looks like it could interfere with the engine exhaust, leading to loss of thrust, uncontrolled spinning, and general mission failure. I try to move it by carefully spinning around the whole NSN, but the fuel lines don't move - maybe the autostruts are doing a bit of work there? I am forced to do something extreme: I use the Service Probe and push with the rocket against the fuel line

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Detaching the Service Probe. Without fuel tanks. Ooops!

However, in separating the probe from NSN, I give the order to the wrong docking port, resulting in the probe being detached without fuel tanks. Damn! Doesn't look promising for making a full Jool 5 without reloads. But here, it's still a minor inconvenience, I can send up a new one

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The new Service probe, about to push against the fuel line

The manuever is successful. I hope. It's hard to be sure, I'm just eyeballing. But it certainly got moved in the right direction, and I know I can do it again if needed.

Still, work on the NSN is not done. I have a few things to finish.

First, I decided in the last few days that I do not feel confident enough about all the landings. Sure, all my landers are fully capable, but mistakes happen. Maybe in landing on Tylo I wait too long to reignite. Maybe on takeoff from Laythe I flip the rocket.  So I decided, since I have 5 pilots and separate landers anyway, I should send a backup lander pod. Failure in one planet would still let me return science from 4 moons of Jool, and complete the caveman. For the Jool 5, I'd have to reload, of course as part of a different continuity.

I also have to send up Liliana, and I have to deorbit Bill and send him up in EVA so he can place struts.

I decide to do multiple things together by sending up Liliana in the backup lander pod with the struts.

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But I did underestimate how much weight the struts would add, so the first launch was lost. Here shown with insufficient deltaV to reach orbit

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It took 3 launches to figure out I need extra fuel tanks. Of course, as long as I can detach the pod with the parachute, Liliana isn't in any danger

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I didn't take a pic of the straightened fuel line, so here's one. Liliana should be already docked, but her ship is covered

Then I send up a very simple pod to collect and deorbit Bill

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The Bill recovery pod

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Here jettisoning the engine before atmospheric reentry

And finally, Bill is sent to orbit inside a cargo bay. By now I practiced the manuever already, having used it in part 6. I already had a functional rocket for the task. It has a lot of extra deltaV for safety, because EVA astronauts are always exposed to atmosphere also in a cargo bay, and make a lot of drag.

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Bill in the cargo bay, ready to launch

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And Bill in orbit. He's out of the cargo bay because as soon as I opened it in space, he got squeezed out

But I already established that, any time I leave control of NSN, the struts will be misplaced. So I can't finish now. I have to place the strut and then immediately start for Jool at once. Can't stop until in Jool orbit, where struts won't be needed.

So I stop here and close the game, with Bill floating outside of NSN, the struts already there.

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Bill hanging on a ladder of NSN

Without manuever nodes it's going to be very difficult, but I planned 4000 m/s for the task. If I'm not too unlucky, they should cover for any inefficiency caused by low thrust, bad trajectory, and especially asymmetric fuel tanks. Even with all the effort it took to send them up, I can't wait to get rid of a few dozens of them.

 

Edited by king of nowhere
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Part 16: the day of the truth

After over one month assemblying this monstruous ship, I'm about to discover whether it actually works.

Turns out, Navis Sideralis Neanderthalensis works well enough to reach Jool, but poorly enough to eat through all the safety contingencies I planned, and then some.

Spoiler

I confess, I am nervous. After all the time and effort I put into building this monster, it could end in a moment. A part of me would just want to postpone this indefinitely. Another part of me can't wait to discover how this will turn out.

First thing to do is to place struts as needed.

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The first group, linking the lateral crew cabins to each other and the first drop tank in each line to each of those cabins; it should stabilize the fundamental framework of NSN

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Then binding the fuel lines. The plan called for one strut every three tanks, but different line lenght got in the way; the new plan is then "do what you can"

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First line is done

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this fuel line deviates outward greatly, and its tanks are too far from the others for struts. I strut them to each other to make a rigid line, in the hope it won't interfere with the exhaust

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After about one real life hour, work on the struts is completed

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It doesn't look any better. Do I really want to try and send this thing to Jool?

Leaving NSN, even just to go to the tracking station, will delete the struts, so from now on I cannot stop until I'm around Jool. Now it's the real tense moment: what will happen when I turn on the engines?

Well, not as good as I was hoping, not as bad as I was fearing. NSN can move on its own power. Wobbling is a real problem, though. And wobbling get worse with acceleration. NSN was never a high thrust ship to start with - 112 tons of thrust for a 530 ton ship, giving a terrific TWR of 0.25 - but even that is too much. I have to shut down two of the poodle engines. Soon I decide to just jettison them, if I can't have thrust I may as well have weight reduction.

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Still, looking at this horribly mangled ship, it's already incredible that it can move at all

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Jettisoning the poor poodles

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Jettisoning some spent fuel tanks. For balance, I am draining them in pairs

Fuel management wasn't as bad as I feared. I don't have to manually set priority in every single fuel tank. I just have to activate staging on the relevant docking port, and the game already assigns higher priority to the tanks attached to it. I set up a few tanks in advance and keep setting up new tanks as I drain the old ones, doing otherwise would be too inconvenient.

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Raising orbit gradually

Of course, with such a low thrust, I must raise periapsis gradually. And there's a real problem here, because I won't be able to get a direct Jool intercept from Kerbin's orbit. I will have to raise apoapsis in solar orbit, where it's a lot more expensive to do. Everything else woud be horribly inaccurate and potentially even less efficient.

Still, the ship is behaving well. According to calculations from the screenshot above, NSN spent 450 m/s to raise apoapsis to 950 km. It should take 400 m/s in an ideal situation, but considering the low thrust, most of the inefficiency is cosine losses; the residual wobbling is not meaningfully impacting performance.

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Final burn in Kerbin's orbit, trying to get as much speed as possible

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lots of discarded fuel tanks

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NSN in solar orbit

I got a solar apoapsis of 25 km. I don't know how much extra deltaV l I'll have to burn to make up for it, and I don't want to know.

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NSN is dropping a line of discarded tanks like so many breadcrumbs

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With reduced weight, NSN is gaining more acceleration, and it's wobbling again. Given that in solar orbit cosine losses are not an issue, I jettison the remaining poodles

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More discarded fuel tanks on the way to Jool. Each of those orbits is a couple of 5-tons tanks, giving an estimate of 130 tons of fuel for this manuever

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But NSN is en route to Jool!

It took over 300 tons of fuel, out of the 450 available; enough to be worried about, but not so little to call a mission failed already. I have estimated that I am fine if I can get to Jool with 150 tons of ship, and I still don't know how the intercept will go. Next manuever is a plane change.

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Eyeballing a plane change between planets is not easy, but I managed pretty well

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Jool is visible! It can be seen a lot better in game, because at high time warp it can be seen moving

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Intercept?

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Nope, missed

I'm not worried about hitting Jool, its SoI is big enough that even if I miss, I am guaranteed to hit eventually in some subsequent orbit. Still, "eventually" is a very long time, so I bring up my tool to calculate orbital times - adding a new line for solar orbit - and do some math. Turns out, NSN is in a 2400 days orbit. Jool's orbit lasts 4845 days, which is conveniently slightly over twice NSN's orbit. NSN must gain some distance on Jool, and if it makes two orbits Jool will be slightly behind where it is now. I'll probably have my intercept then, without further course correction. Indeed, after 11 more years of time warp....

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Similar to the picture above, but Jool is slightly behind

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And this time, there is the intercept

800 Mm is not great, but could be worse. Of course, trying to set up gravity assists without manuever planning is unthinkable, I must get captured by Jool the expensive way

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First thing to do around Jool is to take a science reading and drop the spent canister. At this point, every mass reduction counts; I regret not discarding 200 kg of unused struts

I want to stabilize NSN around Pol, or close enough. For this I could make a capture burn at periapsis, then lower orbit. But I decide to try and lower periapsis already, then make a capture burn. I am pretty sure it can be more efficient; I have no idea, though, how efficient I can be in practice; I can only hope. A purely radial burn would push periapsis down effectively, but it would increase intercept speed on Jool. A purely retrograde burn would push periapsis down and reduce intercept speed, but it's not efficient to reduce periapsis much, and would result in performing most of the capture burn with no Oberth effect. I decide to burn halfway between retrograde and radial, hoping to get the best of both worlds, and not the worst.

Lowering periapsis even more would likely result in a cheaper capture, but there's no way I want to risk crossing the orbit of Tylo and risk getting an accidental encounter that would fling NSN in an intercept course with something else.

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Intercept lowering burn. Not many fuel tanks left. On the plus side, NSN doesn't look like a monstruosity anymore

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50 tons of fuel later, I have my Pol-leveled periapsis.

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And 20 more tons enable capture in Jool orbit

I was supposed to reach Jool with at least 150 tons of ship, equivalent to 4000 m/s spent. That's twice as much as a regular Jool transfer - including gravity capture - but considering all the horribly inefficient manuevers I had to pull off without planning, it could have been even worse.

But I'm not safe. I would have been safe if I got this much fuel left while orbiting Pol. I am still in high orbit. However, after some consideration, I decide to stay here.

Pros of being around Pol:

- cheaper to reach from the other moons

- a lot easier to perform rendez-vous around it

Pros of being in high orbit:

- saves at least 500 m/s to get captured by Pol

- at apoapsis, lowering periapsis is a lot cheaper, resulting in less cost for getting a Tylo or Laythe intercept. Conversely, this results in a higher intercept speed while around those moons, but in that case I will get Oberth effect to help

- cheaper to make the plane change for Bop

And while it's more expensive to reach from the moons, by the time the shuttles are returning, the lander part will have been discarded, so there's only a couple of light crew pods to carry; by far most of the fuel is spent reaching the moon, so if I can make that cheaper at the cost of making leaving the moon more expensive, it's a gain.

I really don't fancy trying to get a rendez-vous in this orbit - I still need to get within 100 km to even set up a target - but I don't have any fuel to spare. I loaded a lot of extra for any inconvenience, but I ended up eating through all of it to raise solar apoapsis. If I had some less, I'd probably call the mission a failure. As it is, I will have to take some additional risks.

Edited by king of nowhere
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Part 17: Tylo's revenge

Heaviest lander is spent first. Coming to land on Tylo.

Spoiler

First thing, I need to prepare the lander with the shuttle to bring it to Tylo's orbit. It requires some rearrangement of stuff around the docking ports, but I planned this part well and everything worked

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First, the taxi grabs two expendable experiments, for Tylo space high and Tylo space low. That small fuel canister has enough for small docking manuevers

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Second, the taxi then grabs some fuel tanks. The first one is almost empty, so that's 21 tons of fuel

I ran some calculations, and I established for safety I'd need to carry 25 tons of fuel. Then I ran some more calculations, and I established that if I used those standards of safety for all the landings, I'd run out of fuel before leaving Jool. Finally I run some more calculations, and I established that I could perform the mission with 20 tons and a reasonable level of safety, and if I kept those standards through all the Jool 5, I'd have a reasonable amount of fuel to return on Kerbin. Alas, those are the conditions I have to work with.

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Three, Tylo lander is undocked. Quidatta on board

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Four, it grabs an expendable experiment. It wil be used on Tylo's surface

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Finally, it docks with the taxi

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At apoapsis, a small manuever is enough to lower periapsis enough for a Tylo encounter

Yes, that thing wobbles. But once it is pointed in a direction, it can hold it with SAS just fine. It helps that it has very low thrust, reducing the problem of acceleration for wobbling.

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Spent fuel tanks can be jettisoned by undocking the ships. The docking manuever costs less than 1 m/s. Here it happened during the plane change manuever to align with Tylo's plane

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Just a nice pic of Jool with its three main moons. I've been there so often, sometimes I forget to notice how beautiful they are

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Timing the Tylo intercept

Of course, it would have taken a stroke of luck to intercept Tylo already. But I have a plan. With those two screenshots, I took the exact time when Tylo passed at the orbital intercept, and then when the lander passed at the same place: 2 days 2 hours 51 minutes later. Then I took the orbital period of Tylo, and compared it to the calculated orbital period of the lander, and it was around 62 Tylo orbits. So I calculated how much I must lower apoapsis to get an orbital time exactly equal to 62 Tylo orbits minus 14:51 hours later, and did a correction manuever accordingly.

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Got a 9700 km periapsis

It worked. Sort of.

No. Not much. I'd have had better luck just going random, Tylo's SoI is big enough. I missed it by 10000 km, which is 1/7th of its orbital radius around Jool.

Why it didn't work? Well, I took the exact time when Tylo passed in a place, and the exact time when the lander passed in exactly the same place. Except that while time can be taken exactly, with caveman limitations "exactly the same place" can only be gauged by eyeballing it. So, of course, its accuracy is crap.

With such a high periapsis, injection is going to cost a fortune. I have to capture in high orbit, with minimal Oberth effect. Then I have to lower periapsis to low orbit. And then I have to lower apoapsis too. And none of that can be made any cheaper. I even consider skipping injection burn, getting thrown around by Tylo's gravity, and just take my luck that the next passage (because statistics dictate there will be a next passage) will be closer. However, I have no idea where this unpromptu gravity assist will send me; maybe in an escape route from Jool, maybe in a collision course with Laythe. Didn't want to risk it.

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Before the injection burn, science readings are performed. An expendable experiment is jettisoned. Everything to reduce weight

The fuel tanks I brought are not going to last, but I still have one card up my sleeve: the Tylo lander has a lot more deltaV than it needs. I packed it to use in an emergency, and this definitely qualifies. After some calculations (good thing I like running calculations, this career is forcing me to do a lot of those), I establish that I can sacrifice some two tons of fuel from the lateral drop tanks of the lander; it will lower the lander deltaV to about 5000 m/s, which is still a reasonable margin to land on Tylo. And it will mean I'll have two tons of extra fuel to return from Tylo, while only carrying the taxi and the lander pod for a total of 2.5 tons of dry mass - so those two tons of saved fuel will translate to a lot more deltaV.

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Burning some of the fuel from the lander

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In low Tylo orbit

And so I finished on a 20x20 orbit with 5 tons of fuel left on the taxi. After discarding the lander, it will be enough for something between 2500 to 3000 m/s, which are a safe amount to return from Tylo.

The orbit is also a result of calculationeyeballing. Being unable to experiment, I went back to read some of my old entries; in particular I read the Flying Christmas Tree mission, when I landed the Dancing Porcupine on Tylo, and there it was written that I had to drop the lander from 30 km to land safely. But Dancing Porcupine had very low thrust, and other related issues. I figured, with a much higher thrust, 20 km would be fine for this unnamed lander. I'm also making sure to land in a flat, low area of Tylo, because 20 km would not be enough if I landed on some of the tallest hills.

Dropping the lander now.

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The first pair of drop tanks was already partially drained to circularize. Soon, they are empty.

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The second pair of drop tanks last longer. So far, all is nominal

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With less extra fuel, I risk waiting a bit longer to reignite the engine

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But I stumble upon some hills; the ground is coming up faster than I can slow down

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Fortunately, this lander has super powerful engines, and it can brake and stop itself in time

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Landed on Tylo

And so I landed on Tylo in nanocristalline diamond.

Well... almost. I almost landed on Tylo.

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How it actually went

So, the lander came very close to the ground, it hit a bit hard on the ground, and exploded. What next?

As I was mentioning in part 15, I am treating the caveman and the Jool 5 as two distinct challenges. For this reason, I saved the game before trying to land. I was hoping I could do both at once, but now the two careers are split. They are in different time continuities.

For the caveman challenge, I am now very happy I brought along a backup lander pod, and very unhappy that I didn't brough along a second backup. I will land where possible, and try to return to Kerbin with what science I can, and to finish the caveman challenge.

Then I will load the game from before this accident, and I will try to finish the Jool 5 too. I'll still try to not save scum - in particular, I won't use it to simulate manuevers: no blindly trying with 10 different apoapsis and use the one that gives the lower intercept. But I'll definitely be able to reload if some lander accidentally crashes.

Actually, I first started to complete the Jool 5; I went as far as rejoining the Navis Sideralis Neanderthalensis around Pol, before realizing that it was practically a test run for the caveman Jool 5, so I should do the caveman first.

Anyway, what went wrong with the lander? Actually, a lot of things.

PROBLEM: the lander is very stable at high speed, but in the very end of descent, where small changes in speed will change its direction, SAS will try to compensate for those changes. And it will cause the pod to wobble. And the SAS is incapable of compensating for wobbling, and it makes the ship wobble even worse, sending it spinning out of control.

SOLUTION: when close to landing, switch from "hold retrograde" to "hold still"

PROBLEM: when close to landing, the engine has such acceleration, turning it on will give a powerful jolt to the lander. Which will then start to wobble, and lose control

SOLUTION: don't activate the engine with "Z". Use the shift key, it will power it up gradually and avoid the hard jolt.

Ok, I can accept that. I could not test the lander in an appropriate environment, those are things that only happen because of high ship thrust and high Tylo's gravity. Landing on Tylo is hard, landing on Tylo without rehearsing the mission first is very hard.

PROBLEM: even at moderate speed, the landing legs will explode. Or maybe they will bounce hard and crack the docking ports.

PROBLEM: even in case of successful landing, the SAS attempting to correct for wobbling will cause a resonance of more wobbling. The stress of it will cause the landing legs to explode.

WHAT THE HELL?!?!?!?!?!? :mad::mad::mad::mad::mad::mad::mad::mad::mad::mad::mad::mad:

Now, I did specifically test for this on Kerbin, because it was something I could test for. I had the lander standing on its legs, and they supported the weight well. Then I dropped it from some height, slamming into the ground at 10 m/s, and the landing legs held perfectly; I experimented multiple times, never any problem, it consistently survived unschated. Now, I tried that landing at least a dozen times, probably more, and I even managed to touchdown at as little as 3 m/s, and still those GODDAMN ######## LANDING STRUTS MANAGED TO EXPLODE! This makes no sense. If it wasn't for the whole "wobble" problem that was legitimately something I couldn't prepare for, and that still would have managed to destroy my lander in the first attempt, I'd petition the challenge keepers for kraken attack. I even managed to safely land, once, only for the lander to start shaking and explode all on its own on the ground.

I accept losing because there were problems I did not foresee, or could not foresee, or could not prepare for adequately. I accept losing because the task I set myself for - land on Tylo with caveman lander, without rehearsing the mission first, or conducting any test in situ - is too hard. But losing because this game is kidding me? Because my craft consistently survives a 10 m/s touchdown during testing, and it does not survive a 3 m/s touchdown in the actual mission? Not so much.

I finally solved all those problems only when I retracted those ######### landing struts and landed without them. I could have saved 200 kg on the lander had I known in advance.

Well, anyway, I'll go on with the caveman. Then I'll be back, and I'll pick up the Jool 5.

 

Edited by king of nowhere
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Part 18: the path of least excitement

Losing the Tylo lander also lost my confidence in the mission; I opt for a less ambitious plan, with two landings and three flybys

Spoiler

I feel cheated. Betrayed. Confused.

When I started this challenge, the idea of no saves seemed crazy. I like to experiment, to push the limits, and I can't do that without some trial and error.

Then I gradually came to appreciate it as a different way to play. You still can push limits, you just have to have a robust enough design that it won't fail catastrophically. It's an additional gameplay-altering challenge.

And then I took a lander, which I tested as much as i could on Kerbin, and I had validated that it will survive a 10 m/s touchdown. I repeated the test at least four or five times, to be sure, and it never broke anything. And then it did touch down at 5 m/s, and it still broke. I don't see any way I could have predicted it, or prepared for it; indeed, I did predict the chance of it happening, and I did carry a test in harsher conditions than those of the actual landing. Now I've reverted again my stance, and I see no saving (and especially no testing) as a form of fake difficulty. I'll go and quote the relevant passages from the tvtropes article:

Quote

 

When you play a video game, you expect to be able to use your skills as a gamer to beat whatever challenges the game throws at you. If the challenges require a lot of skill, the game is hard to win. If it doesn't require much skill, it should be an easy game. However, some games [....] threw in something which makes the game harder, but which has nothing to do with the player's skills. [....]

There are five main kinds of fake difficulty:

[....]

Denial of information critical to progress.

[....]

The outcome of the game is influenced by decisions that were uninformed at the time and cannot be undone.

 

I had no way of getting the critical information that the landing struts would fail - indeed, every information I had pointed to them working all right - and the outcome of the game was influenced by that and cannot be undone.

You could ask, why then did I pick up the nanodiamond challenge? I could have done a challenge with the same exact conditions, except reloading allowed. But I want my badge. I blame my gamer pride. It's a lesson for the future.

And how many future disasters are waiting me? Maybe everything else will work perfectly, but what if it doesn't? Can I trust the Vall lander? It uses the same LT-05 landing struts that caused the demise of the Tylo lander. Do I want to risk another pilot on them? And let's not even talk about the Laythe lander; until three days ago, if I'd been told something would have failed, I'd have put my money on it. I was actually quite confident about the Tylo lander.

Well, let's then put together the facts. I can't complete a caveman Jool 5 with no reloads and no testing in situ and no kerbal on a ladder. I can and will complete a caveman Jool 5 with no testing in situ and no kerbal on a ladder, but with saves.  Right now, I just want to finish the nanodiamond challenge. And for that, I don't need a Jool 5, or even a Jool 4. Science from space is already more than enough.

So I cancel the planned landings on Laythe and Vall. Those won't happen anymore. I won't take those risks. I will still land on Bop and Pol, the lander for them has only 3 parts and no treacherous landing struts, they still feel safe. And I will make flybys of all the moons. Including Tylo, since the science data about it was in the science container that's now irrevocably lost on the surface of Tylo.

 

With this change of plan, I go forward with the mission. The first thing to do is to recover the taxi module. Which has to make a rendez-vous in high Jool orbit without being able to target NSN, unless it comes within 100 km.

Once more, I resort to calculations. I calculate NSN orbit as 629.9 days. Then, at apoapsis, I know it will reach periapsis in half that time, predicting a periapsis at 22:359:1:46 precisely to the minute, so all I have to do is to time the Taxi to arrive at the same place at the same time.

Then I realize, how the hell do I do that? I can't see where periapsis is, and even if I could, at this scale I could have the two periapsis perfectly superimposed on the map, and still be thousands of kilometers away. There's no way to make such a rendez-vous. I have to go around Pol after all.

First I go with the taxi, because NSN is still one year away from its periapsis. Also, it's got no fuel problems, and it's a good training for doing it with the less forgiving NSN.

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First, I get into an orbit closely matching Pol

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And I hope that just passing close will be enough, but to no avail

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Pol is taunting me, so close in the sky, but I'm still not reaching it

How long did I move around like that, with Pol a big ball in the sky, just outside its SoI, but unable to get in? Too long. It took over one year from Tylo to reach Pol. And Pol has a 1000 km SoI; trying to do a rendez-vous within 100 km of the intended target is foolishness. Not technically impossible, but I certainly don't want to try it.

By the way, in the previous entry I mentioned that I was starting with the Jool 5 before realizing it was akin to testing, and I realized it when I got to practice rendez-vous in this scenario. So this is the second time I reach Pol this way; the first time it was actually even harder.

I keep refining the orbit to match Pol more closely. The problem is that Pol has an eccentric orbit, so you can't just match apoapsis and periapsis, because your orbital periapsis and apoapsis will be in different places; burning prograde/retrograde will give gradually better approximationthough. And when you are that close, manuevers are cheap. By the way, I am confident I am close enough to just point the ship towards Pol and eyeball the burn, I've done it with Minmus and to return on Kerbin after achieving solar orbit, but in all those cases it required an expensive burn; I can't afford to waste fuel on NSN.

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At last, the two orbits are virtually overlapping

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And finally the taxi gets a Pol intercept

I like Pol's low gravity; you can turn a collision course at high inclination into a circular orbit almost for free.

Then it's Navis Sideralis Neanderthalensis turn. The manuever is the same, and now that I have some practice, I can reliably perform it in 10 minutes of real time - and several months or even years of game time.

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Here discarding a piece of the Laythe lander; if I'm not landing anymore, I may as well use the fuel and jettison the heavy engines

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Chasing Pol

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At Pol

Looks like I forgot to take status screenshots of how much fuel I had before and after. But to get to Pol NSN drained the Laythe lander, which had something like 7.5 tons of fuel, and the Vall lander, which had an additional 2.5 tons, and perhaps one more fuel tank, resulting in somewhere between 10-15 tons of fuel for a 100ish ton ship.

Now I can use the backup lander pod to land on Pol. The docking is a bit difficult because the lander itself has no control, it is jettisoned like a debris and the lander pod has to go and chase it. And the lander pod has no propulsion, so I have to use the taxi, grab the lander pod, then grab the Bop/Pol lander, and finally release the taxi. Or, I could use the service probe, but I already have my only remaining level 3 pilot in the taxi.

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Chasing the lander

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Once powered, the lander grabs two expendable experiments. One is for low orbit, because NSN parked higher

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Low space on Pol starts at 20 km, as soon as possible the experiment is used and jettisoned for reduced weight

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Coming down

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Landing

All went without a hitch. Well, at some point I got caught staring hypnotically at the landscape and I almost forgot it was time to brake, but I still wasn't in much danger - I could have waited at least five more seconds to wake up. Anyway, no bad surprises here.

Call me paranoid, I'm probably being one right now. Probably the other landings would have gone well too. But after putting almost two months of work into this mission, after seeing it fail for something that I specifically tested and validated and could not have foreseen, I have reasons to play safe and take the lesser prize.

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Ditching the last expendable experiment

Returning to orbit was also unremarkable. Pol is also small enough that getting within 100 km of another orbiting ship is trivial. Thanks for exhisting, Pol! I already liked the place a lot for its rock formations, but now I'm having even more reasons to appreciate this little moon.

 

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Part 19: Bop, Bop, Bop, Bop...

Landing on Bop, obviously.

Spoiler

I was a bit worried about the Bop rendez-vous because I have to manually match orbital planes in Jool's orbit. The deltaV map reports as much as 2400 m/s for such a plane change. Then I realized that the deltaV map assumes one starts from a low 210x210 Jool orbit, and tries to make a plane change there. Starting from a higher orbit, with much lower speeds, I should spend no more than a few hundred m/s on it. So I pack a single fuel canister, which equates to over 3000 m/s. More, considering I'll be shedding pieces.

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With three expendable experiments: space high, space low, and surface

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Plane change. The multiple moons make those manuevers around Jool a fair bit harder to eyeball than on Kerbin

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And matching Bop orbit

Alas, in my haste of matching orbit, I did it when Bop is on the opposite side. Now it will take years of slowly catching up to get an intercept.

Well, I don't want to spend more fuel, and there is no penalty for waiting. So, 5 years later...

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Bop landing also went without a hitch. As well it should, it's not difficult at all once you're there. And rendez-vous with Bop was also no more difficult than on Pol; I still had to match plane in any case.

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Returning to orbit

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Matching plane with Pol

The fuel counter is very low because I'm draining the lander's tank. And the lander's engine cannot use the main fuel canister, because the lander pod has a thermal shield blocking fuel flow.

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Rejoining NSN, still with half the initial fuel

 

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Part 20: Bouncing around the moons

For the three inner moons, I reduced the plan to a simple flyby. All three are performed in the same expedition.

Spoiler

With Bop, I got science from 7 biomes, each worth from twice to thrice a Mun biome. It would be enough to finish the challenge already. But the flybys are not dangerous, and I didn't launch a 500 ton ship to Jool to make two meager landings. I want to return with some honor.

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So, grabbing 8 expendable experiments

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And 3 fuel canisters, of which 2 are half empty

Six experiments for space high and low on the three moons, one for Laythe atmosphere high because I want to make a small dip, and one for Jool space low, if I can. As for fuel, I wanted somewhat over 3000 m/s deltaV, and I needed 10 tons of it. It will last more, because I will gradually lose weight discarding science experiments, but in this mission I have no way to precisely estimate deltaV and I must be generous.

The three inner moons are a completely different environment than the outer moons, being bigger and closer. Even when you're very close to Pol, it's very hard to get an intercept; getting one by accident is incredibly unlikely. On the other hand, if you're crossing the orbit of Tylo, you are guaranteed to get an encounter soon enough.

So, my cunning flight plan entails crossing Tylo's orbit, and then bouncing around the moons randomly, trusting the law of great number to do most of the job. The fuel is for necessary course corrections, because getting out of a crash trajectory from the bigger moons is expensive.

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To start, just lower periapsis enough to cross Tylo. And match plane, of course

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Sure enough, without any further planning, a few orbits later I got an encounter

And with a 5 Mm periapsis, which is a lot better than what I got the first time I went to Tylo and I tried so carfefully to match orbital times. There must be a lesson about not trying too hard somewhere in here.

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By fortunate chance, this flyby is on the right side to get a gravity assist that will lower my Jool orbit

I did consider manuevering to get a low periapsis and low space science, but it would be quite expensive. As I got, by complete chance, a trajectory that will be good for exploring the other moons, I stick with it.

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And shedding the first experiment

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The resulting orbit crosses the path of both Vall and Laythe. Wonderful! Once more, I only have to trust the law of great numbers

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Sure enough, I got a straight encounter with Laythe

A straight collision course, actually. Here I have to spend quite a bunch of fuel to avoid the collision. Not before shedding another spent experiment, of course. On the plus side, I can control my trajectory to get an atmospheric dip.

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Also shedding the first spent fuel tank. It was half empty to start with.

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Preparing for atmospheric dip

Laythe atmosphere is brutal, it gets very thick very fast, and will trash an unprotected ship. I'm not sure where it starts getting rough exactly, and I can't go by trial and error, but I feel safe in a 1.5 km dip. It will still be enough to make the overheating bar appear on the last science jr.

I'll only spend a short time in the atmosphere, so i preselected all the science instruments to be able to take a measurement quickly.

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Orbit on exiting from Laythe

The manuever to avoid the collision slowed me down a lot, I almost got intercepted by Laythe, so I'm now in a low-ish Jool orbit. I consider now lowering periapsis enough to get a reading in Jool space low - I even started the burn - but then I realize it's super expensive to lower periapsis so much, and my fuel is limited, and I can't reload if this goes wrong. So I ditch the idea of getting Jool low - together with the expendable experiment that was reserved for it - and raise apoapsis for Vall

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Like this

Getting to Vall required a bit more planning - and manuevers - because it's much smaller. I at least had to raise periapsis enough to avoid encountering Laythe again

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It did cost some more fuel, but I got a good encounter here too. There are two ships because the game tags the spent experiments as ships. I'm deleting them manually because they are confusing. Except here, because it will crash on Vall anywway

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And shedding another expendable experiment in low Vall space. The last one is for Tylo

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I also fix inclination. It's going to be worse if I encounter Tylo with an inclination and enter a polar trajectory

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Leaving Vall

Raising periapsis to avoid a collision with Vall also got me captured around the moon. I have to spend some fuel to leave it, but I can at least control the direction

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I can't, however, make precise predictions on how much deltaV I'll need, so I end up overshooting Tylo's orbit by a fair bit

Not a problem. As long as I cross Tylo's orbit, I will get an encounter, sooner or later. More sooner than later. Tylo's SoI is as big as 1/7th of its orbit, making encounters very likely.

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I did have to raise periapsis above Vall, though, because I was about to get another encounter with it

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Again in collision course. Straight on collision. Had to spend a lot of fuel to turn this into a flyby. That's why I wanted to carry over 3 km/s.

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I opt for a 90 km periapsis

I am again getting a gravity assist from Tylo, this will propel my orbit up, and I am afraid a too close flyby will directly kick me out of Jool. In fact, I could have used a higher one, because I'll still end with a 1.3 Gm Jool apoapsis

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Discarding the last science container

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And the resulting 1.3 Gm Jool apoapsis

Actually, at this point I could have gotten the space low reading. I still have 1500 m/s of deltaV, and from such a high apoapsis I could have lowered periapsis to 3000 km with minimal cost, maybe 50 m/s. And with maybe 100 m/s I could have turned my orbital inclination 90°, to avoid crossing the moons and risking an accidental flyby sending me who knows where. And then again 100 m/s to return to an equatorial orbit, and 50 m/s to raise periapsis, I could have reached low Jool with as little as 300 m/s. But I didn't think about it, and I discarded the science experiment for reduced weight anyway.

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Returning to NSN. By now I have enough of posting pics of rendez-vous with Pol, so I skip straight to target

This trip lasted almost three years, that final orbit was one year by itself and some of those parking orbits took their time to produce an intercept.

Now I can return to Kerbin, and claim that this after six weeks of preparation this mission wasn't a total failure after all.

 

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Part 21: Return of the king

Navis Sideralis Neanderthalensis returns to Kerbin with its full crew and a lot of science, ending the caveman challenge.

Spoiler

Back when I started this challenge, I thought I could return from Jool with 1000 m/s. Which I could, if I could get a close Kerbin intercept; not very likely. I'm more likely to get something like a 50 Mm intercept, forcing a lot of rocket braking. Fuel is no longer a big deal; giving up on two landings allowed me to save on the fuel to cart a heavy Laythe lander all the way to Laythe, as well as use its 8 tons of fuel for NSN. Still, I can't be sure I have enough, so I still proceed with what has always been my emergency fuel saving return plan: tearing the mothership apart.

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Grabbing those crew pods...

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And discarding them, one by one

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Until only one remains

In a greater emergency, I could ditch that pod too, and use the taxi's terrier engine. But it would be terribly awkward to pile all of those fuel tanks in a line. Since I do have all those fuel tanks left, it's not such a big emergency to justify ejecting this last crew pod. And it has the most efficient engine.

So, good news. The crew will travel in comfort. There's extra living room because one of them is not coming back, but better to not remind them of poor Quidatta too much...

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Jettisoning also the crew pod needed to control the Service Probe. For this, I need to first dock the lander pod with the Service Probe

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The final result; NSN has shed a good half of its dry mass

Now the mothership has a good 4000 m/s of deltaV even before considering the drop tanks, so I'm confident.

I still have to drop the taxi (Mk1 command pod on the top left of the image), but for a glitch I can't decouple it from its fuel tank. And I want to drain it first.

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Here I drop it, in the first stages of the Pol ejection. Goodbye, Pol

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Ejecting in Jool orbit. Trying to make the Jool ejection already in Pol orbit would be too complicated

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Now ejecting from Jool

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I.... was expecting a lower periapsis. I really overestimated Jool's Oberth effect. Had to spend an additional 1000 m/s to finish

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Perfect Kerbin periapsis. NSN still has 16.5 tons of fuel. Worth 2850 m/s, without counting what is gained with the drop tanks

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Not that there's many tanks left to drop. The last two, half empty, and the connectors

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Plane change manuever to match Kerbin. Hard to eyeball with all the cluttering from planets, but I did a good job

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Now, taking the time for Kerbin's passage

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And for NSN passage at periapsis

Once more, I use calculations to get a Kerbin intercept. Kerbin passed at NSN periapsis 199 days before the ship, so the new NSN orbit will have to take a time that's a multiple of a Kerbin year (426.09 days) minus 199. My tool returns an apoapsis of 60.606 Gm. Doing this on Kerbin is a lot easier and more effective than it was for Pol, because Kerbin has a perfectly circular orbit. Meaning, if I have a periapsis of 13.338 Gm, I am guaranteed to be perfectly touching Kerbin's orbit. I don't have to worry that the orbit is higher in one place and lower in another.

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The new apoapsis. The manuever was fairly cheap

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Four years later, Kerbin is close. Did I do the math right? Did I approximate too much?

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Kerbin is visible in normal view. At least, if you look very closely

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Yes! Got an intercept! And a close one, too

When I calculated the time of the orbit I approximated to the nearest day, so I either got extremely lucky, or this strategy is a lot more robust than I assumed. I mean, there is a fairly long stretch where the orbit of Kerbin and the trajectory of NSN are practically overlapping, so I'd guess the method is robust.

Which means I could have used it to get a better Jool intercept, instead of just eyeballing it; it could have saved over 1000 m/s of deltaV, turning the mission into a piece of cake. Well, except for the Tylo landing, of course. I'm uncertain if I should replay the mission from the beginning.

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With a relatively low periapsis, it is convenient to push the apoapsis for an aerocapture by just burning radially. Without a bit of residual inclination, I'd have been in a straight collision course

Now I have to separate the three reentry pods - the lander pod, and the two Cetotheriums. I can't have them reentry at the same time.

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To split them up, Cetotherium 1 burns retrograde

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And lander pod, coupled with the Service Probe, burns prograde

Cetotherium 2, instead, got accidentally drained of its fuel by a mistake in staging - and a mistake in not having disallowed fuel transfer from it. It will stay with NSN until the end, when I'm sure there's no longer need for corrections.

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The train of three pods

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The lander pod uses the fuel left in the Service Probe to slow down

Yeah, I just remembered, I did specifically test the Cetotheriums at 4000 m/s because that's the speed of a reentry from Jool, but did I actually test the lander pod? Not sure. And the previous entries don't even mention it; one moment it doesn't exhist, the next screenshot it's already docked to embryonic NSN and I was like "oh, by the way, there's the command pod too". Better to brake as much as possible. In fact, I should have burned out the fuel in NSN instead of abandoning it.

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Jettisoning the cover for the thermal shield before reentry

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Reentry at 3700 m/s

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Seems safe enough. The thermal shield reaches that level of overheating and stops there

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Landing on a parachute, all successful. Jeb is returned with the science cache

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The other ships are still a few minutes away. I wanted to make sure to distantiate the landers, and I had plenty of fuel

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Cetotherium 2 is undocked

I tried to slow it down too, but NSN is too asymmetric now, and it lost all its reaction wheels. Can't use the engine.

On the other hand, I'm quite confident in the Cetotherium. Not much because I did specifically test those in a 4 km/s reentry with full success (though that helps), but because I already secured the science cache, if Liliana and Bill die here it means nothing for the challenge. What, the microphone was still running? Damn!

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Hitting atmosphere at 4.1 km/s

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The remains of Navis Sideralis Neanderthalensis burn and explode nearby

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Goodbye, brave ship! You've performed marvelously! At least, you performed better than the extremely low expectation. And WILL SOMEONE SHUT DOWN THOSE MICROPHONES?

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The ablator on the pod doesn't even take damage. On the other hand, the parachute is at risk, but it survives

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Coming down a bit fast, but crew pods are strong

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The hard landing broke the thermal shields, but the crew is safe

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Finally, the last Cetotherium. I burn all its fuel to make it lighter for the final impact with the ground

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It lands safely on the sea

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I got 768 science points from Jool

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I dropped quite a lot of used parts around the whole Kerbol system. There's over 90 of them scattered around. For some reason, the game tagged them as probes instead of debris

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And the littering around Jool. I really am a caveman; I still haven't discovered recycling

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Finally, challenge complete

And with this, my foray into no save, no testing is officially terminated. I considered making another mission to rescue Quidatta from Tylo, but it would be long, time consuming, and not particularly exciting. It could make for a cool challenge, but I'm not looking forward to more caveman. I want to go back to piloting cool ships like A'Tuin.

But the report is not finished; next I'll reload to the alternate timeline where I did land on Tylo, and I'll try to complete the Jool 5.

Edited by king of nowhere
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Part 22: Spinoff challenge: Jool 5

Tylo landing; once more, with clarity

I could not complete the Jool 5 in the nanodiamond challenge, but I can still reload back to then and try to complete the caveman Jool 5.

I must reinstate for additional clarity: this is not part of the nanodiamond challenge; it is a different challenge, with different rules, starting as a spinoff from the previous challenge.

In this stretch, I go from reloading with NSN having just reached Jool, to landing on Tylo and reuniting at Pol.

Spoiler

Basically, the purpose of this challenge is to take NSN and see if I can complete the Jool 5 challenge with it. To do this I must reload, so of course that part of the previous challenge gets dropped. I don't want to go all-out on this, though, because it would remove most of the point of doing caveman. If I can perform a burn 20 times and see what brings me closer to the target, it's almost like having manuever nodes. So, the new rule is that I can save and reload, but I must try to not abuse it. Which is not a very clear condition, but trying to define it better would be too complicated, I'll just go by heart.

As I completed the nanodiamond challenge, I got more practiced in navigating around Jool without manuever nodes, and I gradually came to realize how much I could improve on anything. I had previously kept a saved game after successfully landing on Tylo, but I realized I was already woefully inefficient in getting there. In fact, I was very inefficient in getting to Jool in the first place. And I'm not talking about the whole "boost your apoapsis while in solar orbit" business; that couldn't be avoided with such a low thrust. But I've been very shoddy in the Jool periapsis, and I had to spend a lot of fuel for capture. I learned, in coming back to Kerbin, that you can indeed be very accurate with the timing method. And that I could have gotten a much closer Jool periapsis if I tried - resulting in several tens of tons of fuel saved.

I briefly wondered if I should reload back to Navis Sideralis Neanderthalensis leaving Kerbin. But I quickly decide not to. Reloading that far back entails strutting everything again (and those fuel lines are very long, I can't just leave the struts in the crew pod inventory and place them). Then do all the gradual apoapsis raising around Kerbin, which took well over one hour by itself. Then I have to keep making manuevers in solar orbit, and then I have to wait a decade in time warp. And I really don't want to repeat that. If I had a save from NSN in solar orbit, I'd restart from there, but alas, I didn't take such a save - why would I? I took a save at the beginning of the manuever and one at the end as insurance against kraken attacks, but had no reasons to make more saves.

Instead, I'll reload from NSN captured in Jool orbit. The first thing I do is to jettison the backup lander core, it saved me in the ncd challenge but this time it's only dead weight.

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I was here. This is where this new challenge will branch from the old continuity

I won't describe again in detail what I'm doing, as the previous entries have enough descriptions on how I am getting intercepts without manuever nodes.

One thing I realized from the previous attempt is that I was being very generous with my fuel estimated. Which is ok if I can't reload at all and the slightest mistake will cost me a month of work, but in this case I can be a bit more relaxed. Not too much - my heart interpretation of the "moderate use of saves" rule means I can't keep extremely tight margins and hope to succeed, I must have a good idea of what I'm doing. But I don't have to carry 1000 m/s extra just on the offchance that all goes wrong, either.

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So, this time I carry one less fuel canister for the Tylo landing

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Tylo lander assembled

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Instead of performing calculations to get a Tylo intercept from an extremely high orbit, I lower Jool apoapsis a fair bit

The cost is small, as long as I'm this far from the gas giant. And a much shorter orbit gives me a lot more precision. I'm not going for precision, though; figuring that Tylo is so big, I'm just time warping until I hit it by accident

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Plane change. Unfortunately the nodes are in the fast part of the orbit. But the plane change is only a few degrees

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Four years later I got, by complete chance, a 4 mM intercept. Which is more or less average luck

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Discarding the expendable experiment in low orbit

Yeah, the expendable experiment. At this point I realize I failed to bring one along for the surface. No, it's not strictly required, but it's still part of the challenge I want to perform. So I had to reload back.

On the other hand, I realized I still had a lot more fuel than I was using - especially because the actual lander, it has so much extra fuel I can use some of it. I don't have a good enough margin to skip a fuel canister entirely - I could do that with manuevers nodes, surely, but blind I'll still have inefficiency - but I put down a full canister and I loaded up a different, half empty canister.

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Reassembling the lander, this time making sure to have the proper number of expendable experiments and only 14 tons of fuel for the taxi

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Lowering apoapsis. This time I lower it even more than the previous one. It's only a few tens of m/s in practice. And again I just wait for an intercept

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And a straight-on impact course! Actually this is not a great outcome; with a periapsis of -500 km, it will be relatively expensive to raise it above the surface. But I'll then have a huge Oberth effect to use for the capture

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I am not burning in a radial direction because trajectories this close to the planet center have very sensitive inclinations. Instead, I am pushing at the 90° marker to try and get an equatorial orbit

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Good periapsis

Pushing periapsis out of the planet, now the rest of the injection burn should be cheap. Tylo SoI stretches to 10.8 Mm, so I'm still not in a stable orbit, but it won't take much to lower that. And so far, I only spent 5 tons of fuel. Of course, the real unavoidable cost of a Tylo mission is circularizing the orbit.

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Lowered apoapsis to 400 km, still 4.5 tons of fuel remaining

I could still brake for 200 m/s, but I realized it's a waste to carry the taxi to low orbit and then up again. The lander has more than enough fuel to deal with this.

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Detaching lander, still full

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Jettisoning the first couple of drop tanks

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Jettisoning the second couple of drop tanks

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About to land

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:mad::mad::mad::mad::mad::mad:

As I described in part 17, the landing struts are faulty bugged (I'd call them faulty if they just didn't work. But if they work on Kerbin but not in less stressful conditions on Tylo, I'll call them bugged), and I had to retract them to land. Unfortunately, with the struts retracted, the lander has a much more narrow base, and it touches down with the engine bells. It happened to land on a slope, and it just couldn't stay balanced. I had to try this landing a few times, because this time I didn't care where I landed and I ended up in a mountain area.

By the way, I was reasonably sure I recognized this massif as one I did cross with my Dancing Porcupine rover one year ago. I once crashed the lander because I was getting distracted trying to recognize the valley I named "el camino de muerte". Turned out, I was at the right longitude, but I was missing the inclination by a good 5 degrees, and that's why I couldn't find it.

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Almost did it, falling again...

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No, it stabilized. Finally made it

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Jettisoning the spend experiment

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And all the empty fuel tanks

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Takeoff! With high thrust, I am keeping a low inclination, doing a gravity turn as steep as possible

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Last stage engaged

That was too steep a gravity turn. I crashed into the surface. It's curious how "not repeating manuevers many times for the best result" does not apply to takeoffs. It's a psycological thing. Probably my brain considers information on the ships and their performance to always be fair game, while information about the orbit - in a challenge with no manuever nodes - to be unfair knowledge. Anyway, I repeated the manuever ending the first stage at a 10 km apoapsis, and that was enough.

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In orbit, with 500 m/s left. Now will return to the taxi

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Equalizing the orbits...

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What the hell is that? Where is the rest of the taxi?

Damn game won't name the discarded pieces properly. It tagged as "ship" that spent tank, while the actual ship got labeled as a probe - and I disabled probe visualization because most spent tanks were labeled as probes, and I have some 70 of them around.

I like to keep those discarded stuff around just to see the sheer amount of junk I'm leaving behind in this caveman challenge, but in this case I make an exception and delete those pieces of debris whose tag and name can create confusion.

Before that, of course, I reloaded back to Tylo surface. Because I forgot to take a save while in orbit. Playing no save for a couple of months messed my instincts.

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Here jettisoning the last stage of the Tylo lander after emptying it

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Have to reach Pol. Tylo has a huge Oberth effect, the previous time I ended up overshotting Pol and had to lower apoapsis, this time I'll just give the barest push. That should be enough

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Actually not. But it's the kind of mistake that I pledged not to fix. Still, I've got plenty of fuel to reach Pol leisurely

I've got 3.5 tons of fuel left, so I could have totally used even less fuel for the taxi. But the intercept was rather lucky, I couldn't count on always having that.

I'm getting tired of going to Pol by now... Now it's NSN turn

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Status in high Jool orbit

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Status around Pol

This time I skip directly to the end, showing I spent some 15 tons of fuel to get there. There's some 54 tons of fuel left, but a couple dozens of those are the landers themselves. Still, it should be enough to finish.

Edited by king of nowhere
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Part 23: Spinoff challenge: Jool 5

Bop and Pol

Sending the small lander on Pol and Bop. This time with a lot less wasted fuel.

Spoiler

I'm going for a level 2 Jool 5, meaning that one different kerbal must land on each moon. On Pol and Bop, which are easiest, I send Bill and Bob.

Landing on Pol is barely worth mentioning. Seeing as the mothership is already around Pol and everything. Lacking SAS is the only thing that make it vaguely annoying.

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Releasing the small lander

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beautiful Pol is always worth taking some pics

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Landed, spent minimal fuel. The small lander has over twice the deltaV it needs, but then, there was no reason to pick an even smaller tank. That fuel will not be wasted

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Returning to orbit.

I realize there's one tool allowed by the caveman rules that I've not used: the alexmoon transfer planner. Sure, I didn't use it because transfer windows and precise manuevers are meaningless here; but it can still return me a good indication of what's the best cost I can get for a manuever. Add some 50% to that for a reasonable expectation of fuel to carry.

So I do that for the Pol-Bop transfer, and it turns out it can be achieved with as little as 400 m/s. And here I was so worried about plane change!

I send the small lander with my most empty fuel tank. This time Bob will land.

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Heading for Bop with a minimalistic convoy

The alexmoon planner has an additional use: knowing the ejection deltaV. Even without transfer windows, just touching the target orbit immediately saves something. Of course, it's not going to work perfectly when one is eyeballing the alignment too.

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Plane matched. Still 1 ton of fuel in the taxi

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Orbit matched with Bop. This time I made sure to not have to wait 5 years

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Bop visible. Would be better visible if it was brighter

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Now Bop can be easily seen. This is the annoying part where you see the planet keep moving around and you never manage to get closer

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Finally, the intercept

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Detaching the lander

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Landed. It still took a pittance

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Leaving Bop

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This time the eyeballing of speed went well, almost perfect match. Now it only needs some adjustment

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Wait, it looks pretty close. Can it actually be an intercept?

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Yep!

Remember when I said that it's impossible to get a Pol intercept by accident? Turns out, I've done it often enough to invoke the law of great numbers.

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Returning to NSN

I actually drained all the drop tank. The taxi own small tank, though, has a bit of emergency fuel for such times.

Ok, this part was easy. Next I'll discover whether the Laythe and Vall landers would have actually worked.

 

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Part 24: Spinoff challenge: Jool 5

Laythe

Landing on Laythe. Which turns out to not be trivial

Spoiler

I've always been confident on the Tylo lander up until the moment it exploded. The Laythe lander, however, doesn't inspire me much safety - to the point that in ncd I didn't dare to use it without a backup. Now it's time to see how poorly it flies.

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Assembling the lander

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The lander is ready

One additional thing that worries me about this vehicle is that during assembly one of the lateral tanks got misaligned, as clearly visible in the image. I should really have undocked and reattached it, but now it's too late; I have no more ways to ensure proper alignment.

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The leftmost tank is attached poorly

This alignment problem is going to cause a lot of fuss with aerodinamics; it's going to put torsion on the whole ship. I lost one of my fuel tank launcher for a similar problems during NSN assembly. Still, now I can only hope it won't be too bad. I did pack a crapton of deltaV specifically as backup against anything.

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The lander with the taxi, fully assembled

I'm carrying 7 tons of fuel, equal to 1200 m/s. 1000 m/s to get to Laythe, then aerobraking, and then the ship is going to be a lot lighter; I'm also counting on extra fuel left from the lander. If I was still in no save mode, though, I'd want at least another big canister.

Crew members are still Liliana and Quidatta, as my most skilled pilots; but this time Liliana will land and Quidatta drives the taxi.

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Ejecting from Pol and touching Laythe's orbit

To reach Laythe, I used the time-tested method of calculating time between passages. The lander reached periapsis 3:12 after Laythe, and Laythe has an orbital time of 14.717 hours. A bit of calculation returns a new orbital time of 55.668 hours to meet Laythe again without lowering apoapsis too much.

However, I did a sloppy job fixing the plane, and so I entered Laythe with a high inclination.

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Entering Laythe SoI. Great periapsis, but horrible inclination

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Adjusted periapsis, but I'm short on fuel

Laythe is a terrible environment to manuever. You normally want to perform all those radial and normal burns in very high orbit, going slowly, to minimize the cost. But Laythe does not have a high orbit; it's SoI ends immediately. It's the body with the highest orbital speed at the edge of its SoI, by far. And this means that, even if you keep the apoapsis as high as you can, those manuevers are still going to be very expensive. Moving periapsis out of the planet was fairly expensive, and changing inclination is out of the question.

pAzRoAu.png
Capture burn. The explosion on the left of the navball is an expendable experiment recently discarded

Laythe's atmosphere gets too dense too fast to aerobrake without a resistant ship, so I must perform a capture burn. Once captured to the edge of the SoI, I can let air do the rest of the job over multiple passages. I only brake the lander, of course. I keep the taxi in high orbit, I hope the lander will return to orbit with enough fuel that lowering the taxi orbit won't be needed.

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Detaching the lander

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final plunge in Laythe's atmosphere

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I timed the passages correctly so that I'd land in the Degrasse sea, away from any island. Reminder: the Laythe lander cannot land on solid ground

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Parachutes opening correctly. The speed is still a bit too high, though, requiring some rocket brake

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Woops!

The first time I landed, I braked too early, so the lander still picked up speed before splashdown, and exploded. Yep, I've been absolutely right in aborting the Laythe landing in the no save career. Even if everything else works, it still was dangerous.

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Repeated the landing, this time activated the engine at the right time, splashed down gently

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And now, takeoff time

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Stabilizing speed...

This lander has aerodinamic so bad, it must go straight up at low speed. You can look on the low left corner, roll and yaw are close to maximum sollecitation; should they reach the point where the ship can't compensate anymore, it would spin out of control. Of course climbing this way is very expensive, but it's the only way. I did pack a lot of fuel specifically to be able to do this.

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At 11 km, starting gravity turn

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which promptly causes the rocket to flip

I've done this launch many times, and there's no way to prevent the rocket from flipping if one tried to turn before the lateral tanks are detached. Either go straight up and never touch the controls, or face flipping. However, the rocket has so much extra deltaV, even flipping won't stop it

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As the rocket goes higher and slowers, drag goes down, and eventually control is reestablished. The last stage still has enough to orbit

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orbit achieved, with 300 m/s left. Despite flipping

I'm wondering if this makes the vehicle a good lander or a bad lander. It's a bad lander because it has terrible aerodinamics and everything. But a good lander because it can still do its job despite everything.

Unfortunately, I wanted to land the same capsule everywhere, and this forced the small docking port and the bottleneck in the rocket shape. So this lander was always going to have terrible aerodinamics, no matter what.

Anyway, I launched equatorial, hoping that I could then equatorialize the orbit of the taxi. But it turned out, it would take too much fuel. So I launched again, this time in polar orbit.

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This time without flipping, to orbit with 500 m/s left

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Matching plane used of most of that fuel, though

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Aerobraking the taxi to meet the lander

But it didn't work. Changing inclination was too expensive in any case, and the fuel reserves were too low. If this was a normal game with manuever nodes, I'm sure I could find a way to reach Pol with the few fuel left, but I certainly cannot in those conditions. So, I reloaded back to Pol. And this time I loaded 2 more tons of fuel. And this time I will be more careful about inclination

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The nerw lander, with an extra fuel tank

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The two pics to take the time between passages

It turns out, taking the time like this is extremely efficient for those close orbits. It didn't work the first time with Tylo because I had to wait 60+ Tylo orbits, and I got a bad impression from it, but whenever I needed an encounter in two, three or five orbits, it's always been amazingly accurate. Unfortunately, here it was too accurate: I aimed for the center of the planet, and I did hit the center of the planet, with a periapsis of -500 km. As I stated earlier, it is awfully expensive to change periapsis when coming on an intercept to Laythe. So expensive, indeed, that I decided to reload the game and add one more hour to the orbital time to not hit Laythe so well.

This is straying dangerously close to the self-imposed rules, it's not much different from trying many times and getting the best result. So I've only done it once, and I kept the second result: a -350 km periapsis.

In retrospect, the thing to do would have been to raise periapsis on the jool orbit itself, to ensure I wouldn't point straight at Laythe but a bit higher.

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The new intercept

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Status after capture

In the above screenshot I completed all the manuevers to enter a stable orbit around the moon, and I've still got 2 tons of fuel left. It was more expensive than the previous time, because I got a worse intercept; but the extra fuel made up for it. This should be enough to return.

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Landing again. This time I didn't pay attention to where I'd fall, because reloading is allowed; and I almost hit an island

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And back to orbit. I spent enough space and pics talking about flying this craft, I see no need for more

I flew the lander to an equatorial orbit, and I used all the fuel left to raise apoapsis - so that I won't need to lower the taxi too much. I reached an 850 km apoapsis. I saved some 40 m/s for docking.

Now I start slowly lowering the taxi's apoapsis with aerobraking, until they match.

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Matching orbits, mostly

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Rendez-vous. The taxi can be seen as a dark speck on the left edge of Jool's disk

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Jettisoning the spent lander

The fuel left in the taxi is enough for 1800 m/s, and I already start with 300 m/s over a low Laythe orbit. The alexmoon planner gives 1200 m/s as cheapest transfer, 50% more than that is safe.

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According to the tool,  need 750 m/s of deltaV for ejection. Low Laythe orbit is 1900 m/s, I'd need to reach 2650. But the trajectory is not straight, so I add some more

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Too much. Really too much

But don't worry, there's enough fuel to return from this too.

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Lowering that crazy apoapsis, matching plane with Pol, still 740 m/s left

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Returning to Pol, with 600 m/s

This landing had a few hiccups, and I'm definitely glad I didn't try it in the no save career. But with some extra fuel, everything works out - everything except the timing mistakes on the final rocket brake, I still missed that two times out of four.

Now I only have Vall left. Jeb will pilot there. I'd make sure to send Val, except that she died.

 

Edited by king of nowhere
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