Breaking Kerbal Space Program by Only Using Monopropellant

hey guys today i'm back in kerbal space program and i want to try making a rocket using only monopropellant now it's normally just used for like rcs thrusters when trying to dock spaceships they're doing something similar to that so as a fuel source it tends to be really bad in comparison to liquid fuel but i want to give it a shot to see if i can get something in orbit with it so let's get right into it so i'm looking up into the sandbox now and you see the first thing i'm doing is placing in a crew capsule now usually the next thing i do is just start slapping on some fuel tanks but before i do that i want to see which one of these is the most efficient since i had a feeling this was going to be a real fight now to find the efficiency of a fuel tank what i care about is the amount of energy the tank contains divided by the tank's weight now since all these tanks are carrying the same type of fuel the amount of energy they're storing is directly proportional to the amount of fuel they contain so they swap out energy for fuel now we have a useful equation the game actually specifies both of these values for every tank in the editor so now i can go through and just calculate the efficiency of every tank after doing that the first thing i noticed is that they're all really similar now the small tanks tend to be a little worse but otherwise i can't really go wrong here so i'm just gonna use the fl r120 and the cylindrical tank throughout this video since they tend to be a good size for everything so i just start by stacking on some of these flr 120 tanks but there is one thing i do here i want to point out you see after i had four tanks i actually take them off the rocket and i hit control z this replaces the tanks in the ship but keeps the ones that are in my hand so i can stack them on the bottom so this i can effectively double anything i have and you'll see it will be the source of a lot of pain in the future but for now works out quite well and after we do that next thing i want to do is just add on some engines and give it a shot so ramp up throttle and hit space to launch it and it's not bad no it's bad it doesn't go up very fast at all and you can see here once it burns out it gets up pretty high but not that high so to make it go a bit faster what i want to do is double up the engines and once i do that now i have 16 and it should be a bit better so ramp up throttle again turn on my stability control and go straight up but you can see with this rocket after i go up high enough i'm going up about 40 000 meters and that didn't seem too bad at all but there's nothing on this rocket yet and i wanted to start putting on some payloads and to do that really i want to look at some mining equipment here because i was a little optimistic i thought maybe maybe there's a chance i could get on something where i could mine and then come home but also i just wanted some sort of weight at the top and it ended up working well to put there so if you put down the refinery piece i want to put down some solar panels to power it but i put on these really large ones and they weren't great but before i took them off i put down some radiators on the refinery since i would need them and after i did that then i took off the massive solar panels since there is no way they are going to be aerodynamically good and once i did that i put down some of these smaller solar panels so you see they look way better so with those in place i put down some landing gear as well and after that i put down a drill and i accidentally put down the large drill because i wasn't paying enough attention so it's way heavier than it needs to be but i want to give it a shot the launch pad and see how it did now keep in mind here i actually only have eight of the engines i got rid of eight of them because i wanted to see how well it would do which is the originally and it's just not good it's just stay in the launch pad and you can see if i deploy the landing gear i can actually get it to bounce into the air a little bit and it seems like it's almost weightless once the boosters are going but it's still just not quite able to start accelerating up so i put down some more boosters like this after i did that give it another shot here and it's going up but it's nowhere near as fast as it was before and it was burning through fuel super fast so to fix that you can see what i'm doing is just sneaking in some more fuel tanks like this and i gave it another shot and now going off the launch pad it's even slower but it ends up getting decently high before it runs out of fuel here and you can see now it's actually only going up about 10 000 meters so with all this weight it's literally going less than a quarter of the distance than it was before so i remove the drill and put on the lighter drill like this and that should help out a lot so i gave another test here and you see it starts to go up and it's definitely better but there's still a lot of work that needs to be done here now that i at least know i can manage to lift this off the ground i want to compare the available monopropellant engines to see which one is the best now to start building an efficiency equation we start the obvious and that's the more force it produces the better so to write this in more equation friendly form i can write e which is my efficiency equals n or the force of newton's produced by the engine now there are a couple of other important factors though the faster i consume fuel the worse the engine is injecting this into the equation looks like this where fuel consumed is in liters per second now i don't like this double fraction thing going on though so i'm gonna move the seconds up top like this now this is actually more than just a notational trick since newton seconds are units of impulse which is change in momentum so the efficiency unit is looking for the most amount of momentum an engine gives to the rocket with a certain amount of fuel now i'm still ignoring the amount that the engines weigh and add that in we can throw it on the bottom this means as an engine weighs more the worse the efficiency which makes sense so to get this working i just need to square the force term and that's it now i'm still missing a bit but this is going to get us in the ballpark where we need to be and here are the results but they're actually not quite right now the game gives mass values for a few of the smaller engines but it actually doesn't calculate any mass or physics in practice so that makes them really strong when compared to the larger puff engine but there's yet another issue that complicates things the puff engine can be controlled using normal rocket controls which makes it way easier to use than any of the other engines here also if i tried to use any of these boosters i would need like hundreds of them which would be not only tedious to place but it would make the game very unstable which already is going to be bad enough so for these reasons i just want to use the puff engine and not hate my life now one to start adding some more stages to the rocket so the first thing you see i'm doing here is putting on some decouplers on the sides and then building up a bunch of fuel tanks in the bottom and this is for the second stage once you do that you see i'm putting some cones on the sides just to make it slightly more aerodynamic and putting on a bunch of these engines on the bottom and once i had that looks pretty good so i moved the whole thing up and i was going to use my control c trick to copy everything over but this actually caused it to crash and i wasn't sure at the time why this happens but i decided just to try it again but this actually just made a crash literally just copying fuel tanks so i was playing it safe now i was copying individual fuel tanks here because i really didn't want to have another crash and i wasn't even sure why they were happening so you can see i'm recreating everything i have a bunch of engines at the bottom once again and i'm just copying the engines this time and once i finished up that ring of engines i wanted to try copying this over but it's going to be a lot more careful this time and to do that i'm placing everything down i'm waiting a ton of time before placing these down again and it seemed to be pretty good but when i tried copying these over this ended up crashing so i wasn't going to make you guys sit through it again but i did manage to get all the engines on and you see here when i give it a test it's actually really strong in fact the amount of thrust i was getting was crazy but i guess that makes sense since now i have eight of these banks of engines all together now the rocket itself wasn't that stable and i had no aero parts on it so it was sort of just wobbling all over the place and it also did that which is very cool but also i noticed when i ran out of fuel i was going to launch the top stage just to try that one out but i actually had no fuel in the stage at all it seemed like the bottom stage must have burned through all the fuel the top stage which is weird because normally liquid fuel engines specifically don't do that so the first issue i wanted to tackle here was the weird wobbling so to do that i just turned on auto strut and put it on a bunch of the parts towards the bottom and once i did that it seemed to be a lot better it still wasn't perfect but it was doing much better but you can see here when i try to turn it still ends up just flopping over but this one's actually just because i have no wings or anything on it to stabilize it so that's what i'm doing here i went for some small ones probably too small but i didn't want to go too big because i really didn't want to weigh this down all that much and it seemed fine this way and also what i'm doing is changing the flow priority of a bunch of these tanks now the floor priority basically all it does is a higher number will drain that tank first so i have all of the initial stage sets so it's the highest priority so the boosters drain all of their fuel first and once those fuel tanks drop i can let them go and then just have the fuel left in the middle tank now this is working here you can see the boosters were actually draining but the small tank was not and as i went up higher and higher i actually made the mistake of burning a little bit too long and i started burning into the fuel and my top rocket so i do have to be a little careful that i don't burn too much fuel and i actually have to keep an eye on that and it's a little annoying but honestly it's not the end of the world now i wanted to add on a bit more fuel as well since i burned through that really fast and to do that instead of just stacking more tanks which was causing the rocket to be very wobbly what i wanted to do is add on a bunch of these cylindrical tanks and completely surround the rocket like this now after i did that i tried copying it over and i was very brave to do this because i thought it might crash and it actually did after loading back in i did actually manage to copy four tanks all at once which was amazing but for some reason i didn't save and also got greedy and wanted to do six and that crashed it so i was thinking actually i wanted to try a different design because that was kind of annoying and i had an idea what if every single fuel tank was itself its own stage so every time i burn through a fuel tank i can just drop it and have a really efficient rocket that way so that's exactly what i have here in fact i'm using a stack tri-coupler so i have three of these sets here so i could just drop three at a time and also get a lot more fuel out of this and here you see i'm putting down a bunch of these puff engines as well and i was sort of just completely surrounding it i had no idea how many i wanted and it just seemed like a lot was good unfortunately i did need to put them at the top though which is going to make stability really really bad but otherwise they would just drop off with the other fuel tanks as they fell off so i had really no choice but to put them at the top of the rocket and here you can see the fuel tanks change super fast but i could just drop them one by one and in theory it'll be really really good so the first few stages you can see here at three times speed it's not bad it's picking up speed pretty well but this really shines as i start going to the top and shutting almost all of my weight so here you see this normal speed you can see i'm just sort of punching it and it just goes faster and faster and faster as more of these tanks fall we're already up over about a thousand meters per second you can see the atmosphere is not really happy about it i'm not really high up enough to really be enjoying the speed properly so with the final stage going i'm just sort of hoping for the best and i was honestly expecting to explode here thankfully it didn't and i almost got two kilometers per second and you see here i have an apoapsis of about 370 thousand meters and that was a lot but this rocket actually still wasn't quite enough to get into orbit but i wanted to try adding some fins to see how good of an orbit i could get out of this but the problem is whenever i try to turn it's so bottom heavy because the fuel tanks i have to have there it just flips over i tried a whole bunch of stuff including adding some structural fuselages and some other stuff distribute weight better but it didn't help i ended up flipping right over and i had to scrap that and i went back to my original rocket here and i wanted to add another stage and this one should be enough to get me all the way into orbit swim back to the rocket i was using before and you see here what i'm doing is putting on some more decouplers because i want to add on one more stage to this and you'll see i'm very carefully placing fuel tanks because i really don't want it to crash so i was getting very sick of that so i put down some more nose cones angled them in after that next thing i did was copied over some engines and i was a little worried about copying here but i learned a few tricks to make it somewhat bearable so it seems like when i copy as long as i don't click anything the game tends to not crash it sometimes still does but it's much less common another trick is that once i copy something i should place it down first because then it seems to behave a little bit better for whatever reason if i put it right on the craft it just it doesn't like that and then it just causes the game to crash but here you can see i got four boosters in place and i actually have five banks of rockets on all of these so it should be plenty powerful here after that you can see here i'm putting down some very large wings put down some of these elevon parts to give myself a little bit of control once i'm in the air and with that decide to load in and give it a shot so the launchpad looked awesome and i hit space and it accidentally became a decoupler test that's fine the coupler looks good after that's the launch way and everything so i guess that's fine but after i fixed the coupler issue give it an actual test now and try to get it into the air so what i was really looking for here is to make sure all the cross feeds are working properly and to make sure that all the things were deploying properly and nothing was interfering so gave it a shot now and actually there's two problems you can see that all the boosters in the bottom are doing that and the mono propellant is not draining properly it's actually not taking from the small boosters it's taking from the second stage so i'm gonna need to fix that so that the staging actually works properly there so since the boosters weren't working quite right i just decided to keep using the first stage of the rocket until i ran through both the second and first stage worth of fuel but actually before i could even get through all that fuel the random movement of all the boosters managed to cause this to completely flip over and there was nothing i could do to fix that so i decided i might as well just still test the decouplers now and i threw out the bottom boosters and they seemed to work fine they kind of exploded but nothing seemed to explode on my actual ship so i guess it was okay i decided to start this one up and you see full fuel and everything's pretty good and i decided to follow this one all the way until it landed and you can see here even though it slammed into the ground the crew capsule is actually fine i have no idea how that survived the impact but it was funny enough i had to show it so with that done i want to give it an actual test here and you can see i'm starting out launching the bottom boosters and right now i have the cross feeds all fixed so it should be draining properly so the bottom boosters going you see they don't actually go up that high before they're already completely out of fuel now the second stage doesn't launch immediately i actually need to press space again to get the boosters to go why did i do this uh mostly because i just didn't stage it properly but also i was a little worried that once i was gonna start this up it might cause some problems with colliding into other stuff if i have to go at the same time so i decided instead make it a separate stage i shouldn't lose too much fuel doing it this way but you see here i launched the top stage of the rocket after that and it's not too bad it's actually going pretty well but i have a kind of a garbage turn here for getting into an orbit mainly because i wasn't paying enough attention to what i was doing so it's just trying to make sure all the staging was properly done and also that the cross feeds were looking good and you can see here i'm really starting to build my apoapsis and it's not too bad but already i ran out of fuel so basically what i want to do to get a little bit further since i'm pretty close to orbit already is actually just add a little bit more fuel to that bottom stage since it burned out really fast so to do that i'm just stacking on more tanks and you see i'm doing it very carefully i'm trying not to copy and paste too much once i do that you can see here i'm copying back on the engine clusters and i'm just going to give this a quick test here and i realized something interesting i stopped the engines temporarily and put them back up to full thrust and this compressed the fuel tanks in a way that just caused them to lose all stability and the bottom stage of the rocket literally just became like a spaghetti or something it was a complete disaster but even in this test you can see here i got a pretty solid orbit going it was already 85 000 meters which was way better than before so with that done i wanted to focus on the top stage of the rocket and actually add on one tiny stage on the top so to do that you can see here i have three fuel tanks and putting some mono propellant engines in the bottom like this after you do that i'm also putting on some docking ports that in the future i'll be able to save bill and once i do that it reattached everything but i actually didn't really like the mining part being there since i wasn't using it anyway so what i did is added in a decoupler and put the rocket on the bottom of the first stage like this and now with the combination of the top stage and the loss of mining equipment i should be way lighter and be able to get out of the atmosphere so i gave it a test here i just wanted to make sure the top stage was deploying properly and you can see here once i run out of fuel in the second to last stage i decouple and once i do this 6c i can start the last stage up and seems to work out fine still getting in some speed so that should be good and now here for the final test really i didn't make any changes i added a few more fuel tanks to the bottom stage but other than that really nothing changed and you can see i'm starting out by trying to get up as high as i can now this rocket is very awkward and i have to very carefully watch the monitor palette and i'm going to be showing that at the top here so after the first stage basically ran out i had 1.72 units of mod propellant left i wasn't going to try to use a little bit of extra money propellant there so i just dropped it to the ground and started up the second stage now the second stage was the most unstable you can see here how much it's wobbling back and forth and i probably could have tuned this a bit more but the problem is really just that these tanks are so disjointed from each other that they just like to wobble a lot so it wasn't really that big of a deal like i still angle it roughly where i wanted it to go and the stage ended up almost completely draining in a good amount of time once it did i just dropped it off and launched up the third stage now even this stage had some oscillating issues but it was totally flyable and i could still manage to point it pretty much exactly where i needed it to go after this it was pretty much just a waiting game of making sure that i'm using all my fuel that i can once i got pretty much all the way down i turned down the throttle and just barely nudged it once i did this you see the monitor slowly goes down i got it to about zero units and i used almost under the monitor propellant in the very top stage after that i launched it and it looks like there's a lot for this little stage to do but this stage is so efficient since it weighs like nothing that it pretty much could just complete this no problem so you see here i'm extending on my apoapsis and i'm actually looking pretty good i'm actually angling slightly down as well to keep the apoapsis from expanding out a ton and once i do this 60 i get to wrap all the way around and i technically have a complete orbit but it's not out of the atmosphere quite yet and there's really nothing for me to do until i fly around to the other side so i have to fly in the atmosphere for a little while but you can see here i eventually work all the way around and it worked the apoapsis and let's do that i still have 300 meters per second of delta v which is plenty for me to finish off the circularization so i just wrap around again and you can see here i managed to get the periapsis and apple apps within 100 meters of each other did i need to do this no but it's gonna make it slightly easier for me in the future when i want to get someone to dock with this and i'll probably have someone save bill at the very end of another recovery mission so guys thanks for watching this video is a lot of fun to make it was definitely a pretty good challenge and a lot of the challenges were not for reasons i was expecting so if you want to see more content like this make sure to subscribe if you have any questions or comments feel free to leave them down below and otherwise until next time

Channel: Reid Captain

Views: 556,567

Keywords: ksp, kerbal space program, ksp 2, kerbal space program 2, kerbal

Id: h9KwYdrOTWE

Length: 16min 21sec (981 seconds)

Published: Fri Dec 03 2021