For want of a really big nail (or possibly a bolt): kerbalism grand tour at hard level

[Vagrant203]

On 6/7/2021 at 2:42 PM, king of nowhere said:

my balance problems are caused by having a broken engine on one side, and having discarded more tanks on the other side. With this, I finally equalize the tanks again

Mechjeb - Utilities - Differential throttle. Automatically manages individual engines to balance everything out perfectly.

[Single stage to ocean]

Really useful and saved quite a bit of terrible launchers, love it. Has a habit of rapidly using ignitions sadly  the Autoland uses too many ignitions, but go to utilities and limit throttle to a min of 0.1%

[Vagrant203]

I've never dealt with limited ignition but that does sound feasible.

[king of nowhere]

Part 12: How to catch an asteroid

Bolt goes to a near-Kerbin asteroid. Not much to do there. The whole experience is quite underwhelming.

Comets, instead, can't be reached with Bolt's resources.

12.1) Finding a target

Spoiler

To land on an asteroid I first need to track it, and to track an asteroid i need an infrared telescope. I don't have an infrared telescope, so I must launch one.

It is technically against the rules of a grand tour, but it's only needed to get an asteroid, which is a bonus target anyway. I'm sure nobody will have anything to say about it.

For once I don't have to worry about redundant launcher, this is just a relatively cheap piece of hardware. It's refreshing to launch something so minimalistic. Until it gets boring.

The antennas (the basic kind, barely visible on the sides of the probe core) are actually too small; it's been a while since I last chased as asteroid, and I remembered the telescope needed to be in high Kerbin orbit - where the antennas would have been adequate. I remembered wrong, it actually needs solar orbit. On the plus side, it does not need to stay connected once it starts tracking, so that's it.

The launcher is pretty hard to use, its baricenter is too far on the back and it wants to flip, but what the hell, I don't want to design a better launcher.

So, I see a bunch of asteroid, all crossing Kerbin in the near future. I pick one whose orbit seems better behaved than most, and I plan a rendez-vous

I took the wrong path to enter Dres orbit, and I now must leave at apoapsis

Alternative Dres ejection: first circularize orbit to get Oberth effect, then escape

Lowering apoapsis would cost me 90 m/s, but it would save 150 m/s in Oberth effect.

So I did not do it, and used the first solution instead.

The problem is, Bolt has low thrust, a long burn like this takes well over 10 minutes, performing it from a low orbit entails a lot of cosine losses. Apoapsis is not a good place to make a manuever, but at least the orbit is slow enough that cosine losses are minimal. And that's certainly worth more than the 60 m/s I can hope to save by lowering apoapsis.

Leaving Dres

Engine pack status; engine on the bottom is shut down to compensate broken engine on top, engine on the left is shut down to compensate nearly empty fuel tank. The roll, pitch and yaw indicators keep track of balance

20 hours ago, Vagrant203 said:

Mechjeb - Utilities - Differential throttle. Automatically manages individual engines to balance everything out perfectly.

Mechjeb does a lot of things, but I prefer to do them myself.

Eventually an engine explodes, so another one is shut down

The service probes are moved on the habitation module, in preparation for dropping the tanks

Reaching the asteroid will require an extra 500 m/s of plance change and over 2000 m/s of intercept speed. A large number, but not surprising; it's basically like paying the intercept speed for a Kerbin encounter, but without Oberth effect. On the plus side, my orbit will closely match that of Kerbin afterwards, so returning to my home planet will be very cheap.

I would have liked to also grab a comet, but it's not feasible with my resources. Rendez-vous with a comet near periapsis requires something in the order of 10 km/s for the two-way trip; I don't have that much fuel. The manuever is much cheaper at apoapsis, being doable with only two or three km/s, but it would take years to reach past Eeloo's orbit and then come back, and I don't have that much food. So, no comets.

It's only a while after manuevering that I did realize I could have saved a lot of fuel by a Kerbin gravity assist. But I have extra fuel, and so it's not worth the effort to reload and lose a few hours of gaming just for it.

12.2) Getting there

Spoiler

I barely had time to reach the plane correction manuever, when i noticed that the intercept had changed

the new intercept; or rather, its lack thereof

Of course, I am (once more) a dumbass. My first intercept was targeting the asteroid's original orbit. But the asteroid got slingshotted by Kerbin, it changed orbit. Well, ok, I am not completely a dumbass because I did consider this possibility. I looked at the intercept. The problem is that the old and new orbits are very close, and it was hard to tell on which orbit the intercept was. Anyway, I still intercept the asteroid's orbit, and I can still reach it in a couple more years for little extra cost, by fixing my orbital time in order to meet it the next orbit

The new intercept

I did not like it, of course. So I went back to see if I could do better. I did discover that no, I can't target the new orbit until after the asteroid has done the Kerbin flyby. And all the asteroids I could see were intercepting Kerbin. I tried finding the one that would do it faster, then wait in orbit around Dres and try to find an intercept only after it had passed Kerbin. All very neat, but it was too far ahead in its orbit and I'd have had to make a double loop trajectory to catch it anyway. No gain.

So I decided to keep what I already had. It will add a couple years to the mission. It's still within my safety storages.

Spreaking of safety storages, just before the first manuever I dropped it

Food was exhausted, but I dropped a lot of water and oxygen

This deserves some explanations. See, when I started this trip, I wasn't sure how well recycing water and air would work. On the Dream Big, I had the greenhouses to confuse the data, and the Dolphins - which used solid oxide electrolysis to recycle oxygen - had some bug related to it. Probably because they didn't have a CO₂ container. Anyway, I figured I could not trust those recycling processes, and so i planned my storages to last for all the mission even in case of no recycling.

After a few years I did discover that, actually, recycling water and CO₂ worked extremely well. I could have dumped my extra water and oxygen supply them. Except, I only included a single water recycler in the mission. They are very heavy, I didn't want to allocate weight for something I wasn't even sure would work. It was basically an experiment, a proof of concept to see if it would work. But I planned the mission assuming it wouldn't. Chemical plants fared a bit better, but I still only had 2.

And so, knowing that at any time a kerbal may have a random breakdown and destroy my only water recycler, I had to keep the water storage. Now I only need 3 or 4 years at most. The single water tank on the habitation module is more than adequate for that. Same for the oxygen. So I can safely dump the extra. It was 11 tons of supplies.

Bolt, further lightened. It doesn't look like a Bolt anymore.

Again, the 2 additional years went smoothly enough. The crew did not gain significant stress, but they still had a couple of accidents - because yes, you can have accidents even before stress reaches 100%.

One such accident caused me to lose more food. But I still have enough to last to year 28

Another one, which I forgot to record, caused me to "dump in space" electric charge! Well, I can only wish I was so lucky more often.

Upon reaching the asteroid, the rendez-vous burn must be started much earlier, because the thrust keeps being low - though by now it has significantly improved with the ship becoming lighter

what's left of Bolt and its huge fuel stock

500 km to the asteroid. The map does not show an accurate encounter marker, but it's easy to follow the navball

Finally, the asteroid

Trying to do something with the asteroid, and failing

Now that I'm here, though, I really have no idea what to do with this thing. I sent out Bob, but I can't even find an option to take a sample (I later reloaded the game and discovered I just had to click on the asteroid instead of the astronaut, but now it's late). Nor are there any science experiments I can make. And of course I can't plant a flag. I could grab the asteroid with the service probes, but to what end?

On 6/8/2021 at 7:18 PM, Single stage to ocean said:

in kerbalism, does asteroid mining have any better things than planetary mining? 

I have no idea, since I don't have the equipment to mine asteroids. But I suspect not. The problem is not mining, it's extracting CO₂ from ore. And that's independent on how well you can mine the asteroid. They may be a good source of water - they should be, if things were realistic. Also, metallic asteroids should be potential sources of uranium, while carbonaceous asterois would be good sources of carbon. But kerbalism is only realistic to screw you. When it comes to resources, it jumps through hoops to deny them, even when it would be realistic for them to be there. Just to test, I strapped the surface analysis module on a service probe and got it to grab the asteroid: it only reads ore concentration. I suspect kerbalism asteroid mining is not implemented at all, but without drills to test i can't be sure.

So, I leave the asteroid without doing anything.

Bolt is down to 450 tons of total mass, 250 tons of fuel. Enough for perhaps 7-8000 m/s, counting the drop tanks. it's enough to still go almost everywhere, but definitely not enough for a comet.

It's year 20  and it's time to finally bring the kerbonauts home.

Edited June 11, 2021 by king of nowhere

[king of nowhere]

Part 13: Homecoming

Finally, Bolt returns to Kerbin, where the last three monoliths are found.

The crew is recovered, the mission is successfully concluded

13.1) Asteroid to Kerbin

Spoiler

Bolt is orbiting an asteroid with an orbit very close to that of Kerbin. Kerbin is slightly behind, to get captured I simply have to raise apoapsis a little bit.

It takes 350 m/s. Notice how I have to set up a second manuever node, else the game won't tell me I have a Kerbin intercept

Coming from a similar orbit, the intercept speed is extremely low, so much that I could get captured into orbit by a Mun gravity assist.

I admit, the visibility in this image is not great

And that's it. This transfer is easy. I just have to wait one year. I just run my last maintenance round

First sighting of Kerbin - by zooming as much as possible

This breakdown caused me to lose electric charge. Wish they were all so harmless

Still high magnification, but now also Mun is clearly visible. Minmus can also be seen, barely, as a tiny dot in the lower left.

Now Kerbin can be seen at a somewhat more reasonable magnification

And finally without magnification at all!

I'm getting a bit emotional, returning to Kerbin after more than 20 years in space. The kerbonauts have been spending hours in the cupolas, watching the tiny dot slowly getting bigger. But they can't land yet, they have a mission to conclude.

I was planning to get captured in Kerbin orbit with a Mun gravity assist, but I decided instead to use a rocket burn and get captured in elliptic Mun orbit. It is a very convenient staging place to explore the Kerbin system, being less than 100 m/s away from Minmus and roughly 100 m/s away from a Kerbin return trajectory.

13.2) The bumpy side of the Mun

Spoiler

I had already marked the Mun anomalies, way back when Bolt was still Nail. But the Mun is full of anomalies, and it takes a bit of searching and comparison with the wiki to find out which one is the monolith. Then Stool is released

Another advantage of using a Mun orbit is that here I don't need Taxi

The monolith is 15° S 70° W, but I decide to land 140° W, just at the mouth of the equatorial canyon. The reason is, I already did drive on Mun a lot of times. I started my career as rover-maker on Mun. My first big adventure on a rover was on Mun, running 600 km on a tiny rover with a top speed of 10 m/s - and a worrying attitude at capsizing even at that speed.

My first Mun rover!

And the sky crane that delivered it. It looked so big at the time! I was so young and naive!

This small rover was unable to safely descend into a crater - even taking a bump could break a wheel! - so I had to navigate a course around craters. On the plus side, it could go up 45° slopes, which my later rover could not replicate, probably because of too much mass and too few wheels. I plotted the whole path in a collage of a dozen screenshots, and I still have it.

And then, of course, Mun was the main testing ground for my most successful rover, the Dancing Porcupine, which still holds a special place in my heart. I've been trying to convert it to kerbalism several times, but I've never been happy with the result; without isru, it's just not practical anymore. On its first mission I landed it on Mun and collected all the biomes I was missing in my career, performing a half-circumnavigation. This time with the capacity to jump inside craters, so it was much less of a hassle.

And then career got too easy, and I started picking up challenges, and I never came back to Mun. Not seriously. A quick landing with the crappiest, cheapest lander I could make work to gather funds to build the Marco Polonium. A quick landing with the Can, the last celestial body conquered by the Dream Big. Never a longer stay.

And all the while I was visiting distant planets, and I did drive rovers everywhere, but no other celestial body is as beautiful to drive on as Mun. Vall comes close, but it lacks the same variety. All those small craters provide unique challenges, as well as opportunities for really cool jumps.

This was a perfect chance to go back and drive rovers on Mun. In italian we made a word for this: "amarcord", which translates to "remembering with nostalgia".

Plus, I wanted to try the reaction wheel driving on Mun, and I never run through the equatorial canyon - while I did the other one with Dancing Porcupine.

Landing

The canyon starts from east farside crater, one of the rougher areas on the Mun. I started inside a small crater, inside a larger crater, inside the big crater. Here Stool is climbing out, it can't take the slope frontally so it's zig-zagging upwards

And here the canyon starts. The equatorial canyon is very bumpy, extremely dangerous. I exploded so many times in this canyon, for a while I even wondered if I was still on Dres (spoiler alert: I wasn't). Of course I could have gone slower, but it would be less fun.

Anyway, the nort-south one was a nicer drive. Even this one, though, is still much better than the Dres canyon.

This canyon also has large elevation changes, so that it can be split in three different sections, each one characterized by a downward path, followed by a climb to a "pass". Here begins the second section, perhaps the most dangerous

this passage is the main reason this part of the canyon is so dangerous

here I decided to try and run down headfirst in the canyon. Of course, I did not survive. Wasn't expecting to.

After a while of having fun of running through the canyon and exploding, I decided I wanted to try an alternate route: climbing out of the canyon wall, and coming back in for the third part of the canyon. It costed a lot of time, and it was still very rough terrain. This area of Mun is exceptionally rough

In this part of the canyon, a crater destroied the southern cliff, turning the canyon into a ledge. At the end, there is the third section

With this the canyon ends. I took many more screenshots, the Mun is really a great place to ride, here I'm only showing a selected few.

After the canyon, the rest of Mun is much more flat. There are, of course, the occasional craters. Stool can jump in the small ones, but the large ones generally require some care. I was able to take them much more roughly with Dancing Porcupine, I think with the latest update, which introduced eva construction, they also made wheels more frail. Of course it is also possible to break the fall with rockets, but deltaV is limited.

I was generally able to keep a speed between 30 and 40 m/s. Going faster generally meant exploding down a crater; Ike is perfect for running because it has long, gentle slopes, where you can keep gathering speed without crashing. Mun, not so much.

Looking down a crater edge

Craters also make it much easier to give names. I called this the skull crater; Not much resemblance with an actual skull, but it does look like Xykon from the order of the stick

The five big craters touching each other form "the question mark"

Finally, the monolith. Now let's go back to the equator, for cheaper equatorial orbit

Going back, this crater complex was as much an obstacle as the canyon. It has 3 crater rims directly one after the other.

Goodbye Mun

And as usual, the path taken

13.3) Minmus: black monoliths matter

Spoiler

Now Minmus. I will send Taxi there. I'm not sure I'll rejoin with Bolt later, or if I will instead directly land on Kerbin. So it's time to put the parachute back.

It's been kept stored under the fuel tank all this time

As I may not have access to an engineer later, I also fix the Kerbin plane, taking the solar panels from the service probes.

Continuing the tradition of the service probes being useful in completely unanticipated ways

An optimized Mun-Minmus trajectory can take as little as 50 m/s, but a couple of weeks. I took a faster, high energy transfer to save time

I don't see much point in returning to Mun, so i send Bolt on an aerobrake trajectory. I will have to raise periapsis to 50 km to avoid burning

Finally, Get Your Tinfoil Hat plans for a polar orbit, because the first time I collected anomalies I did a poor job of it

At Minmus, separating Stool from Taxi

The green monolith is 30° N. There is also the black monolith nearby. I decide to visit both. I also decide to land on the greater flats and cross them all, to see how fast I can go on flat land. Previously, I never figured out I have to shut down reaction wheels to drive on small gravity worlds, and I kept having problems for it.

Knowing how to deal with low gravity, Minmus is a nice, easy drive. A bit boring, though.

Landed. And look at it, no trace of water nor hydrates. On what's described as a slushball. This is a part of kerbalism I did not appreciate

Accelerating on perfect flat, Stool reaches 55 m/s quickly enough. Afterwards, acceleration decreases exponentially, until the wheel limit of 58 m/s, which it couldn't quite cross. It spent 60 km accelerating on perfectly flat ground

Hitting the steep slope at close to 60 m/s, however, predictably results in breaking both wheels. Reload.

Nice view of the sky with Kerbin and Mun

The same, in real colors. It's night, without amplification I wouldn't see anything

A very strange terrain glitch

The rover bumps over it. I crossed it using the reaction wheels to push the front wheels upward

Approaching the black monolith

A problem with finding it is that, seen against the backdrop of space, it becomes nigh invisible. As in this image. Can you spot the monolith? Would you spot it if you didn't knew it was there?

This monolith is black, so it's not worth taking a full crew picture. In fact, it's not my target and I move on. I'm a horrible green suprematist

Even on the hills, speeds in excess of 30 m/s are easily achieved. Compare with Pol, where even downhill there was no way to get past 20 m/s

And the right monolith. As in, the monolith favored by right-wings parties

The path taken

13.4) Kerbin: I can't believe this thing is still flying

Spoiler

Kerbin is full on anomalies, so I checked with the wiki to find the monolith.

The anomaly in the center near the lake is not marked as a known anomaly. Is it the green monolith? (spoiler alert: yes, it is)

Bolt is set to aerobrake. With its high mass it can't lose speed efficiently, so it takes many passes to circularize. Jeb takes a few % of radiation damage from passing inside the radiation belts. After a couple of orbits, to reduce damage to Jeb and speed up operations (not to mention waiting right timing to land close to the monolith), I decide it's time to unleash the plane

It traveled all the way to Eeloo, only to come back. Wouldn't it have been easier to just leave it on Kerbin?

A couple of small RCS have just enough power to push down periapsis

Reentry is harsh, putting the plane to its limits

Reentry just above the monoliths (the top lake on the horizon). But I'm still too fast, I will go long

I took pics of sunsets on Eve, Duna, Laythe, but never on my home world. Here, fixed

It's night, and I have a solar-powered plane. I also need to conserve enough energy to last through the night; there should be no need for life support when I can just open the window, but I don't know if kerbalism will accept that in case electricity run out.

So, I decide to glide down with minimal input from the propellers, land, and wait dawn. I had to shut down science experiments to last through the night.

Just a funny science report

Landed. Now waiting dawn

Nice dawn sky

Now, while the plane is standing still, the propellers look normal. But as soon as they start moving, it shows how badly they are broken

I must stress, there is a problem with propellers if they are activated in vacuum (i did face it in the Jool 5 mission, with the NOT! Albatross), but it's not what's happening here. I launched those planes with the propellers shut down and locked, and they remained shut down and locked during the last 20 years. I only reactivated them after I was deep in the atmosphere.

I have no idea if kerbalism is at fault, or if the propellers bug can strike also with locked rotors.

Anyway, the other times I did solve it by alt-f12ing in a new plane. This time I decided to try and use this one.

And guess what, it worked! Wasn't expecting it. It pulls slightly to the left (it should pull to the right, with the rover arm there. There was a spectrovariometer on the opposite side for balance, but it broke and got dropped long ago), but aside from that, it doesn't even seem to have poor performance. I wasn't even sure how well it would fly regularly, given the poor performance on Laythe. But then, Kerbin has more air.

The plane stabilizes its speed at 110 m/s with open cargo bay, 140 m/s with closed cargo bay; more or less like on Eve. With the sun overhead, it can use the propellers without depleting the battery.

Kerbin is pretty nice to fly over. After so many barren places, I like seeing trees. I did not like my first flying experiences, but now I'd definitely fly over Kerbin again.

the aerodinamic window is still there to help me find the best angle for the propellers

IVA view

Not quite perfect landing. I would blame the propellers for difficult manueverabuility, but maybe it's just the plane model

Strangely, the trees at some point disappear. There are nice forested areas, and barren areas with no terrain scatter. No, it's always the same biome

On the plus side, I started finding baobabs, which were not available earlier

scanning the baobab

spotting the monolith from above

the last monolith

Jeb is recovered afterwards

The trajectory

As for Bolt, I kept aerobraking it to a circular orbit, where I left it parked. Just like the Dream Big, it's still good for another go, it still has 200 tons of fuel, and it would be a shame to retire it before time.

No, I'm not doing anything else with it. But I just like to think that my kerbals will go on after I quit playing the game

Recap of Bolt resources

As for Taxi, I decide to rejoin it wil Bolt after all. Same with Stool, it's still in good conditions. This time I used rocket braking, rover wheels are not resistant to heat.

Taxi rejoins Bolt

The command pod uses its RCS to deorbit

reentry

landing!

This mission was more ambituous than the previous one, but it went with less hitches. It's true that progress entails doing the impossible and then making it ordinary.

coming soon: a preview of the next mission

Edited June 15, 2021 by king of nowhere

[king of nowhere]

Part 14: The shape of things to come

Well before the end of the mission, I've been already working on the next, more ambitious mission.

Moar objectives!

Spoiler

Keeping up with my current trend in this game, after I've done something, I want to try something more complicated.

Ever since seeing the ridiculously complicated isru offered by kerbalism, I've been wanting to find ways to actually make it work. And not the relatively easy Duna option, getting CO₂ from the atmosphere. The really hard one, getting it from regolith.

Unfortunately, this process requires water and a lot of electricity. Performing it further than Duna, with solar power, is too impractical. The only other options besides that are Mun and Gilly, because there is no water on the inner planets. Under those premises, it's actually convenient to only perform isru on Duna anyway, as you can easily reach most places from there.

I've also seen something of the outer planets mod, and I liked it. It is compatible with kerbalism, in that all the outer gas giants have their own radiation belts.

So, I decided that the mission would have two main objectives: a grand tour with the outer planets mod, and performing isru under the kerbalism rules.

Solar power, again, is not feasible. I actually tried a model, but in the outer planets a gigantor panel will produce 0.01 electricity.  I could instead use dozens of rtgs, but I don't like the idea; they are not an efficient way to make energy from uranium, and they would run out with time. In my mind, the framework of the missions is that the kerbals want to go interstellar, building a generational ship to send settlers to other stars, and those grand tours are early experiments, to test technology and crew performance over decades in space. And you can't cross interstellar space with an rtg. But you can with a nuclear plant.

So I've started looking for nuclear plants, and I discovered near future electrics has some that are compatible with kerbalism. They produce radiation, they have  a failure chance, and they  consume uranium that must be mined. Perfect!

This project is even more complex that my previous ones. As it turns out, if I spend too long projecting a ship, I get stressed. I want to fly it. In the past, I've been cutting testing because I was tired of projecting, projecting, projecting all the time. So this time I started building the ship well before I ended the current mission. This way, I could alternate flying an projecting, and keep myself fresh. And so I'm just done with Bolt, and its successor is already mostly done.

The ship is built as a hollow bowl of fuel tanks with the living quarters on the inside. This allows landing on a planet, exposed to solar storms, while still remaining shielded from the sun, wherever it is in the sky.

I also had to fit a spaceplane in there, there was no other way to protect its crew cabin

A view of the inside

Even with nuclear plants, there is still a major limitation to isru: a large convert-o-tron will need over 2 year to produce its own weight in fuel. Make it close to 3 if we also include the weight of the nuclear plant needed to feed it.

After considerations, I opted for a 5000 tons ship, with 500 tons of convert-o-trons. Should take some 20 years for every refueling stop. I expect the whole mission to last 2-3 centuries. To reduce part count, I edited a few game files to make a bigger convert-o-tron, weighting 33 tons and with correspondingly increased production.

I hope it will be feasible in the first place; time warp limitation may make the 20-years refueling stop become too complex.

My current missions prove that a ship can last 20 years with good care, and it's not unreasonable to assume to stretch it to 40. 200 is another matter, though.

So this ship is planned with even more redundancies that usual. It's also planned to take full advantage of eva construction, and be highly repairable. Failing that, it can at least drop broken parts.

I have to finish a few tweaks on some landers, but I expect to be able to bring this new project on its maiden flight in a few days. There it will undergo its most important test: I will land it on Mun, and refill the tank. If that goes well, if it proves that the 20 years refueling is feasible, then I will start posting a new thread.

Edited May 2, 2023 by king of nowhere

[jimmymcgoochie]

200 year Kerbalism Grand Tour with Kerbalism ISRU and OPM!? 

I get the feeling not all the Kerbals who start that mission will finish it…

[king of nowhere]

well, I started it. And so far it looks promising.