Orbiting Kerbin using only Jet Engines | Stock KSP 1.7

hello everyone a while ago i got the idea to try getting into orbit using just jet engines of course in my naivete i got nowhere close to this goal the best i could do was a suborbital hop like the one shown here so thinking it was impossible i gave up on it and moved on to other projects the idea came back to me recently and given everything i've learned about ksp since then i decided to take another crack at it and as you can probably tell by the title of this video i actually managed to do it this time in this video we are going to take on the challenge of getting into orbit using just jet engines for this challenge we will be using stock ksp 1.7 with the restriction that all of the energy for the mission must be provided by jet engines in other words no rockets reaction wheels cracking drives and so on will be used decoupling will be allowed but the decoupling force will be set to zero so no energy can be gained from it okay before i get to my solution let me give you some background as to why i thought this was impossible there are two main factors that prevent jet engines from reaching orbit normally the first is the jet engine's top speed in case p the rapier jet engine tops out at about mach 6 or about 1750 meters per second at 20 kilometers altitude since orbital velocity is closer to 2400 meters per second you can see they just don't have the speed to make it the second problem is that debt engines can't run outside the atmosphere so they cannot perform the necessary circularization burn needed to reach a stable orbit even if the jet engines had a top speed exceeding orbital velocity they cannot enter a stable orbit without the ability to operate outside of the atmosphere these two problems seem like a showstopper for this mission but it turns out there is a way to solve them let me show you what i've come up with introducing the jto 8000 jet powered launcher okay as you can tell by its non-conventional design this aircraft has some tricks up its sleeve but it still obeys the rules of the challenge it's only power source are the eight rapier jet engines running in air breathing mode only and there are no rockets reaction wheels cracking drives or any other propulsion sources here all right let's fire up the engines and get this thing off the ground to see how it works as you can see the disk section in the center of the craft is fairly wide so i made a landing gear carriage to keep it off the runway of course once we're in the air this carriage is dead weight so i'm just gonna ditch it i'll let the cleanup crews deal with the mess the high thrust to weight ratio lets the craft climb very steeply usually with a space plane you want to take a shallow profile to gain speed in the lower atmosphere but i want to avoid that in this case this craft already needs very large rear wings to keep it stable and the extra drag from the shallow ascent would be too much for it to handle alright now that we have leveled out at 10 kilometers let's reveal the first trick of this contraption as you might have guessed from this disc of wing panels in the center this machine utilizes rotation but you may ask what is causing this thing to rotate good question take a look at the drag vectors on the spinning component as you can see the rotation here is caused by the unequal drag forces of the heat shield and nose cone components on the bottom side the heat shield is exposed to the air stream and experiences a high amount of drag on the upper side the much more aerodynamic dose cone moves into the airstream and experiences relatively much less drag as you can see this imbalance of drag forces creates a net torque which causes the entire component to rotate note that i'm still only using jet power here while the drag force is what's driving the rotation it is the jet power that provides the air speed necessary to create this drag another thing you might have noticed about the craft are these odd spinning wing panels in the middle of the main wings the real purpose of these wings is to act as auto strut nodes for the spinning component since these wings are heavier than everything else on the spinning portion all of the heaviest class auto struts link to them which makes for a very sturdy structure this is important here since the arms of this part are all made of wing panels and are susceptible to bending under deflection in the airstream okay the aircraft continues gaining speed until we reach about 1500 meters per second here the jet engines are no longer able to provide thrust to continue accelerating and the speed levels out at this point we need to get as high out of the atmosphere as we can get for the next phase of the mission this is where the rotation comes in the point of rotating the middle section was to store energy from the jet engine so that it could be released all at once with a rotation rate of 10 radians per second and an arm radius of 90 meters the spinning section can fling our payload over 900 meters per second giving it more than enough velocity to leave the atmosphere and we just gotta time it right and there we go the fast rotation rate made this difficult to time properly but it worked out now we have a velocity of 2400 meters per second which gives us an apoapsis well outside the atmosphere that said we aren't out of the clear yet as i said earlier in order to reach a stable orbit we need to gain velocity outside of the atmosphere this is where my second trick comes in notice how the payload is still spinning from being released you probably guessed at this point we are going to use this rotation again to provide the velocity needed all we have to do now is wait for absoluapsis and time the decoupling just right okay time for the moment of truth and stage there we go the radius was much smaller this time so the velocity gain was only 150 meters per second but that was enough to give us a periapsis of 83 kilometers we now have a stable orbit achieved using only the power from the eight jet engine rapiers we started with of course this craft is not perfect by any means the bearing i used wasn't very well suited for this application and had some stability issues plus the craft was only able to deliver a single probe core into orbit that said as far as i know this is the first time this has been done in stock ksp so i'm more than satisfied that this even worked in the first place this mission should serve as a good proof of concept for those who want to improve on it further thank you all for watching the craft file will be provided in the description if you want to try flying or improving on it please let me know what you think or if you have any questions see y'all next time you

Channel: Stratzenblitz75

Views: 989,972

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Id: nX23IRKNaLE

Length: 7min 11sec (431 seconds)

Published: Sat Apr 27 2019