king of nowhere

so, you want to launch a ship from a plane, send the ship in orbit, send the plane back on the ground. how is that possible without the game authomatically deleting the object in the atmosphere while you're not controlling it? looks like the tricky part

i'm not an expert on this, but it's generally accepted that the more mods you install, the more likely it is for the game to crash. especially for mods that alter the game significantly, like RO. easiest path is to remove it., maybe the game works afterwards, and you lost nothing. even if the game doesn't work anymore, you can still go in the game folder, take the save files related to your career (or challenge, or whatever you're doing), save them somewhere safe, and put them back in their folder after you reinstall the game - and the mods you had while it still worked. this should ensure you can save your previous games. another good tip is, make multiple installations of the game for different mods. i myself have 5 different installs. this way, if your latest mods crashes the game, you lost nothing.

@JacobJHC says he doesn't have the time anymore to follow this challenge. He asked me to take it over. In the near future, I will review all pending submissions (except my own) and start working on moving the challenge to a new thread.

trying a sort of nanodiamond caveman in the whirligig world planetary pack. i call it nanodiamond because i have tech at 10%, though i cheated infinite money because i already went through the whole "make a crapton of easy, boring contract to gather enough money to run a real mission" before, and i'd rather cut to the interesting stuff. i also enabled saving and loading, because i can't consistently land on mesbin. whirligig world starts from the planet mesbin, a rocky giant with a very fast rotation. at the equator, gravity is 1.3 g, you need some 1500 m/s of ground-relative speed to orbit (thanks to rotation helping). but there is no atmosphere, so you need to rocket brake every landing. it's similar to landing on tylo, really; it requires a bit less deltaV, but more thrust. which is why i'm not even trying to make this without quickloading, landing is difficult and the slightest mistake will lose the craft. anyway, there are a lot less biomes available than on kerbin, and so i find myself needing to stretch the missions with limited techs. I don't have enough deltaV with a single launch, but i'm nowhere near close to unlocking docking ports. so I got creative when needing to give my ships a boost You don't have to be docked when you can embed your capsule inside a glove-like structure. I called this ship "poor man's claw" here testing, it works pretty well for deorbiting a crewed module after it run out of fuel. unfortunately, the test also showcased poor man's claw doesn't have enough fuel to land itself, after spending most of its allotment to reach Jeb. so I have to redesign it to jettison the tanks and engines, and send it up again; boost the module with Jeb in low orbit, then jettison its tanks and engines, and send up another poor man's claw to bring jeb on the ground. oh, and another for Val. on the plus side, next i'll unlock the stayputnik, so i will at least be able to treat the poor man's claw as expendable EDIT: I failed to consider that the pod to be rescued would not sit perfectly symmetrical. it was very hard, fighting against the control of an asymmetrical ship while trying to rocket-land on twice tylo's gravity. without SAS, because both my pilots were in orbit, waiting to be rescued. but after several failed attempts, i managed to crash-land in a way that left both pods intact.

the ksp1 section of the forum seems a lot less active than it used to be before ksp2 released. if it recovered, it didn't go back to previous levels.

can't you reload the game? if you have decided to make a no reload career without having much practice, then a golden advice is: don't send a crew unless you really need to. in a rescue mission, you most definitely don't need no crew. especially not a crew of 5. anyway, there are ways to rescue your kerbals, but the fast ones require some skill. namely, while your ship is still in kerbin's SoI, you can send another ship, with lots of deltaV, and aim to pass close to the first one. it's tricky because the game won't give you a close approach. So you have to take your original ship trajectory, decide on a position, for example mark a point where the ship will be in 10 days. then find a traectory with the rescue ship that will pass close by in 10 days. once you're close to the ship to be rescued, use the navball. it will take quite a bit of fuel too, especially to revert the trajectory after the rescue. if you accidentally stranded 3 kerbals on a kerbin escape trajectory, and then you accidentally killed 5 kerbals on a rescue mission, then you most likely don't have the skill for that maneuver. which leaves the slow option. your lost ship will go in solar orbit. just send the rescue ship in solar orbit to rendez-vous with it. it's not much different than doing it in kerbin orbit, it's just a lot slower.

ssto is a very generic term, and so are your requirements. if by "orange tank" you mean the 36 tons one, just strapping a skipper engine underneath should give you over 4000 m/s, enough to orbit with some spare for docking. if you want a spaceplane, you make it like you'd make any other spaceplane... i don't understand the question, really.

ah, i see. i never noticed kerbin has a differently-shaped radiation belt. kerbin's belt do hug the atmosphere even at higher latitudes. so no, on kerbin you cannot have an orbit that avoids the radiation. well, unless you stay in a low circular orbit. you could keep your station safely in low orbit by sending 500 tons of radiation shields in orbit

here i'm doing that maneuver. the radiation belt is faint, and you can't see much the third dimension, but you should notice there's a gap between the atmosphere and the radiations, and the ship is passing in between. also, while it's not very clear, i have a maneuver planned at periapsis to lower orbit to the brown dotter one, and that orbit, while considerably lower, is still high enough to avoid the inner radiation belt of jool entirely (it still gets the outer radiation belt, but laythe sits straight into it, so there's no way around). Here I was aiming for a moonlet straight in the middle of the radiation belt, while limiting crew exposure. You can see that the radiation belt only covers around the equator, while a polar orbit will stay too far away from the equatorial plane. Once more, I was aiming for a moonlet in the middle of the belt, but this is perhaps the clearer image. You can see, I am making a very short passage amid the radiations. the orbit goes above the equatorial plane very fast. if I had a lower periapsis, I would avoid the belt entirely.

yes: a polar orbit. radiation belts are equatorial, so if your orbit is polar, with a high apoapsis above the equator, you will pass over and below the belts.

the mass definitely should not be enough to break the docking ports. they may break on the ground under weight, but in space, for rotation, they should not. anyway, try autostrutting. it's the common solution to all stability problems.

of course it's possible; why wouldn't be? from an equatorial circular orbit, it's extremely easy and cheap. you can do the transfer with less than 300 m/s, including the cost to circularize in a low minmus orbit. in fact, i've seen the transfer recommended as training for interplanetary missions, because the kind of maneuver required to go from mun to minmus is exactly identical - albeit cheaper and faster - than the one required to go from kerbin to duna, or to any other planet. from a high polar orbit it's going to be a lot more difficult; you have to time your burn so that you exit prograde to mun. trying it could be good training.

What I've done for all mods: went on the page, followed the download link, extracted the folder, put it into the game data directory. But it looks like I won't need it too much, I have managed to work by moving the ship around - and this gives me an excellent excuse to say I'm not hijacking the thread, if I show what I did so, working on the ship was not nice and it was not pretty, given that this is just the lower third alas, can't be avoided. Kerbalism gives saturn an extremely powerful radiation belt encompassing the inner moons; the only way to land there without getting the crew fried in a couple of hours is carry 20 thousand tons of electromagnetic radiation shields. plus nuclear power plants to power them up and a few bits and odds. I made the ship to be modular, and assemblable in orbit, and I did launch the individual pieces to show that the proof of concept worked. But it would have required hundreds of launches to get it whole - a launcher too big crashes the game by sheer lag, this one is already stretching the limit. So I built that piston on the bottom; when the ship appears on the launchpad, it starts to collapse the piston, and that gives me a few seconds (tens of seconds, due to lag) to cheat the ship into orbit whole. This is Ringrazer, whole. Those tanks are 7.5 meters of diameter. The orange ball on the right side is 9 meters, and it holds 750 tons of water - necessary for the life support of 14 people over a couple centuries, I don't know how long it will take to reach saturn by gravity assists and i wanted to be safe. on a ship this size, a hundred tons of water more or less makes negligible difference on the deltaV. Too bad the ship got torn in half when i tried to turn it around, just by the sheer stress of handling a thing this big and long. but the second time i sent it up, it worked. as big as it is - those are 60 engines slightly more powerful than a stock rhino - the engine segment is severely undersized. again, lag was the deciding factor, the game is already nigh-unplayable as it is. which is what brought me to interrupt the challenge the previous time. i guess i'm becoming more patient in my old age. or perhaps more feebleminded. weird, by calculation i should get 2150*60= over 120k kN, but the game only declares 33000. I will have to look into that and figure out how much thrust i actually have. and I noticed a flaw in some fuel tanks that should hold liquid fuel only and are instead holding a mixture, so I will have to launch the ship again. the fuel switch function is iffy on my current mod selection.

i tried installing both, including the dependencies. didn't work

about one month after saying goodbye to the game, i came back. there was an old challenge where I was trying to work a 200k tons ship on a trip to the rings of saturn, that I dropped because I had other, more pressing challenges. I decided to give it another try. here's the aftermath of an experiment where i didn't have enough launch stabilizers. By the way, does anyone know a mod for having a bigger VAB? the kind of stuff I'm trying to build is way too big to fit inside, and it's bothersome to work on the construction. I heard there were mods for it, but I can't find one

given the extreme length, i would advise hiding the images in a spoiler. perhaps split the post into several subsection, each with its own spoiler, for ease of navigation.

are the solar panels deployed and oriented correctly towards the sun when you leave the vessel?

if the plane turns left or right on the runway, often the problem is wheel drag. select the front wheels and manually reduce their friction, keep the rear wheels with a higher friction

all burns must be relatively short, which is not always the case. if you have a big burn along the way, like for example a jupiter capture burn, then you need to accumulate lots of fuel for it, you need to start the electrolysis weeks earlier. then you need ways to store your oxygen and methane for weeks, which basically forces you to use a criogenic tank anyway

I see. glad the misunderstanging was cleared. the main problem is that it takes a lot of energy to turn water into fuel. a probe would need to spend weeks in preparation, making fuel for a burn. and that fuel would still need to be stored. cryo storage requires more energy in the long term, but it does require a small, continuous amount of energy. solar panels or rtgs produce a small, continuous amount of power, so they are better suited at keeping a supercooled tank rather than operating a high-powered electrolysis device for a short time. I can see the idea working for some specific mission that require lots of relatively short burns, separated by long time intervals. but it would be a special case.

while I thank everyone who contributed with hard data, this particular paper was most informative. I regret that I only have one upvote to give you for it. so, while cryocooling wasn't the main topic, there were experiments made. the values of thermal transfer given with the use of MLI, around 1 W/m2, are consistent with a small probe only needing a few W of cooling power. With a cryocooler efficiency of 5 to 10%, which is pretty reasonable considering the theoretical carnot efficiency for the temperatures involved, a good guesstimate is several tens of watts, up to 100. that's within the capacity of probes like New Horizons or Juno, but it would place a significant strain on their power generation. For starship, the power generation needed would be in the tens or hundreds of KW - could be inconvenient, since the solar panels need to be retracted and protected during aerobraking on mars. the main issue, anyway, is indeed the way the liquid form bubbles that interfere with heat transfer. several experiments were attempted with bringing cryocoolers in space, some were successful, and it was demonstrated a prolonged storage of LOx with zero boiloff, but some failed due to heat transfer issues. sloshing is also an issue; with MMH and NTO, the problem is avoided by using internal bladders and pistons that prevent sloshing, but such solutions would not work in cryogenic conditions. it seems the system is potentially workable, and it is being investigated. However, the specific issues are caused by the zero-g environment, and fixing them requires experiments in zero g, which are very expensive to make. confronted with limited budget, it is preferred to stick to older, less efficient, but tested and reliable solutions. this is turning out to be a surprisingly common answer to a lot of things about space. many practical problems trequire to think a solution, launch it to space, test whether it works, tryto make some sense from the data coming from the instruments, think another solution, wait to launch that in space too... on earth, a team of engineers could fix it with a few weeks of trial and error. but needing to launch every single iteration in space - much less being unable to put your hands on it and having to rely on limited instrumental data to figure out what's going on - increases costs and time exorbitantly. it still does not answer my question on why cryocooling isn't employed on earth. it seems that taking air, cooling it, extracting nitrogen through fractional distillation, and transporting it to the factory to compensate for boiloff is considered cheaper than just keeping the nitrogen cool inside the tank. this baffles me. Still, a potential answer also lies in that paper, when it suggests the main issues of venting are during fuel transfers. so it is possible that the greatest losses to boiloff are not caused by heat transfer, but by fuel transfer - which, in a factory using liquid nitrogen, happens multiple times per day. it is possible the figure for 1% daily losses include those for fuel trasfer, while heat transfer losses are a lot lower. i would still like to hear about it from an expert, but it's no longer related to the field of space travel, and it doesn't belong here.

I realize there must be practical reasons if it's not done. I am inquiring about those practical reasons - because i know enough of technology to not be satisfied of just "there are problems", but i don't know enough to know what those problems are - and most hypothesis i can make on my own seem like they could easily be solved. So, your sarcasm is unnecessary and uncalled for. Similarly, a superficial answer like "in space it gets hot" does not help; sure, in space it gets hot, and it gets cold, and we already have systems in place to protect delicate instruments from that, and you are telling me we can do that but we can't handle a highly insulated tank? If that's the case, i'd at least want a more detailed explanation on the why and how. This forum is the only place i know where i can make highly technical questions and hope for people to give good answers. Many have done so; i'm going to pour over those papers as soon as i have more time. I wasn't expecting to get snide remarks and not-so-subtle insults, though. Nor did i expect such an attitude to actually get upvoted

interesting. but it leaves me even more curious as to why not include a criogenic system - as starship is big and heavy enough that the mass of one should be negligible. in general, while there are some practical problems with installing criogenic cooling units, they don't seeem nowhere near dire enough to justify accepting losses of fuel - or switching to a fuel that gives 30% less deltaV. I got the same issue with criogenic tanks on earth. i've been researching the topic because i am a teacher and i explained storage tanks to my students last month. and for all that i tried, and i found plenty of references to acceptable boiloff, i didn't find a single source even mentioning the idea of providing internal cooling. in the case of criogenic cooling on earth, clearly replenishing more material is not an issue, but i found multiple documents stating that losses of material are 0.3 to 3% of the tank content per day - which, on a large tank, means several tons per day. And I looked the cost of criogenic units, and I saw that you can buy a refrigerator that can reach -200° C for little more than 3000 $. And while I saw dozens of documents saying "losses are acceptable", I didn't see a single mention of the question "but why not avoid losses entirely?". nowhere does it say "preventing those losses by internal cooling would be too expensive" or "would entail too many practical problems". Everything I can find suggest that preventing those losses would be rather cheap - though i am unable to find solid data on that. I was just hoping someone could give me some answers on the actual tradeoff of accepting or preventing boiloff besides the ubiquitous "boiloff is acceptable".

if it's possible to insulate the tanks enough to reduce boiloff to acceptable levels - and it is, the apollo missions used crio tanks for hydrogen that would have lasted years - then you need to remove very little heat from the tanks, a power output lower than a watt. you need little to no ratiator surface for that. this also should address the power issue; it would require extremely little power to keep cool a small, well insulated tank in space.

i often hear you can't use criogenic fuels for probes because of boiloff. so you have to use hydrazine, which has much lower Isp. nobody mentions that you can make a criogenic tank that does not lose stuff over time. you just need to have your own internal cooling system that will keep the fuel cold enough to prevent boiloff. on earth it's rarely done, because most criogenics are dirt cheap anyway (nitrogen, methane) and it's cheaper to just lose some over time. at least, i think that's the reason. i saw that a criogenic refrigerator can come as cheap as a few thousand euros. in space, that cost is clearly not a problem. mass, on the other hand, could be an issue. but i don't have the numbers to make the calculations. those refrigerators i saw looked like they were small enough, could be a few tens of kilograms, though i could not find exact data (most people who buy a criogenic refrigerator doesn't really care how heavy it is). but it seems to me, adding a few tens of kilograms of dry mass should be abundantly compensated by increasing Isp by 30% or more. does anyone know the actual math of why it's not done for space probes? by the way, starship wants to use methane on mars. i suppose, to keep it cool for the nine months trip, they will use this system?