The K Prize - 100% reusable spaceplane to orbit and back

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dogon11 you know the rules permit mod struts and legs?

I think the rules make the challenge meaningful but being a purist inevitably tends to encourage snobbery which is not the right approach in the long run.

So I agree that all contributions are welcome as they can be interesting and creative in their own right and can give ideas and inspirations to other players, so I have made a list for contributors who didn\'t quite succeed yet or who succeeded on their own terms! See OP, 'Gate Crashers' list.

However I won\'t be abandoning the rules and will continue to make a clear distinction between those who succeed according to the challenge rules and those who contribute elsewise ;)

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Single stage to Minimus surface, and back!



Also made it home safe (though not to KSC)

Full flight plan here. Are there more efficient ways to do this? Edit: Androsynth says there is - maintain a steady ~50 degree ascent, until turbojets are at 8% efficiency, then push over to 90,000m apoapsis.

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I enter the Fargo 1, its not space worthy yet but Im going to slap a few Rocket engines to it to get into orbit.

Mine is slightly over the rules becasue it takes off horizontally, goes up into space, and lands horizontally.

Is that too good?

Pics as soon as it is ready.

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Grats to you antbin, very neat. Using the aero fuel in the rocket looks like a good idea. I can see how ASAS is lighter than a cockpit and your cockpit has lowest drag. The long wing has the best lift to weight ratio. Makes perfect sense. I have been trying a bigger craft (about twice the size, falls apart on the runway mostly) and still could not quite make it back from Minmus! Good going.

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Finally, after multiple redesigns, I finally have a good sized space plane that is 100% reusable.

Here it is sitting on the runway waiting for take off.


Shortly after take off it pulls up into a vertical ascent.


I was going for a 100km orbit, but I kind of screwed up and didn\'t feel like fixing it.


Enjoying the view.


Here is the glide shortly after re-entry.


Here is the plane as spotted from a nearby mountain. Shortly after I ran out of fuel making a small correction burn.


Uh, oh. Am I going to make it?


Turns out I was slightly off on my re-entry burn, touchdown was a little early.


I managed to coast back to the space center on the ground. All the plane needs is fuel and a lift back up onto the runway.


Edit: I just realized this thing had no name. It was called 'Space Plane 5' (1-3 were not SSTO, and 4 crashed) in my game. 'A Spaceship' is good enough I guess.

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Nice looking ship SteevyT, congratulations on your orbit and safe return to KSC terrain, for which you get a pilot proficiency medal to go with your back stage pass and party invite!

zekes, good luck with Fargo 1, horizontal lift off is part of the challenge but how you land is your decision. No such thing as too good, if you got it flaunt it!

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My Skylon3 SSTO spaceplaneplane

For reach any Kerbin orbit, and land on the Minmus.

This vay around the Muun is time uneffective but its fun to see 2 moons in one flight.

At launchpad.


At orbit.


Muun FlyBy.


Land on Minmus.


High Orbit.


Back on KSC.


Stock + Mechjeb.

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I\'ve been having a lot of fun working on this. My additional criteria for myself were a) it has to look cool and B) the return has to be a completely unpowered glide back to the KSC runway. So I have spent a lot of time trying to get good gliding characteristics.

I finally came up with this fully reusable SSTO glide-return spaceplane:


After takeoff I do an 70-degree climb to around 11km with the air-breathing engines, where I light the central rocket engine. I run all three engines until around 20km, when the air-breathers stop doing anything useful and I shut them off. The rocket gets me the rest of the way to orbit. I make a 100km orbit with around a quarter-tank of rocket fuel and 2x 2/3 tank of jet fuel left.


The return is a completely unpowered glide, though of course there is tons of jet fuel left if I undershoot the runway.



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I tend to build fairly massive, unwieldy rockets, and this challenge has taught me that subtlety and minimalism have their place.

Specifically, someplace else.


Just a teaser, more later.

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The orbital version of my Vulture craft can do this already. I\'ll take pics of a flight when I\'ve the time.

But I\'ve a question : how do you manage to land back on the runway ? Are you using a joystick, because with the keyboard I always do overcorrections, even when using ASAS and precision mode.

So here are the pics :


On the runway


Going up


The aerospike kicks in


Shutting the atmospheric engines down






Landed a few km away :(


Meh, doing it taxi style is not that bad ???

You might create a new award for this, since I did it back to KSC but didn\'t managed to land there.

If anyone wants the .craft :

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Well done Xeo, nice looking spaceplane, at least your Kerbals didnt have far to walk. I think a Pilot Proficiency Medal will cover it. :)

Well flown The Duck and congratulations to mager42 who has earned the coveted Astrokerbal Distinction.

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heres my orbital flight! sadly i had massive lag when i was trying to land my plane and crashed near the runway. ill try again some other time i guess.

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personally I make a quicksave (F5) before reentry so I can try again (F9) and again and again...! Some designs never fly right but others do once you have got to know them. There is one I am trying to land at the moment and I can land it ok but it always bounces and flips the front end up knocks the engine off the back... I must have tried a dozen times trying to understand the problem, oh well back to the drawing board!

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There seems to be a last gasp of phantom lift just when you land any plane in KSP, all you can do is nose up a bit to lose as much speed as possible before touching down as level as you can.

If you know it\'ll nose up again be ready to tap that nose back down, it\'s times like this that I wish the airbrakes had made it in.

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It\'s back.


Meet the XB-66 Sawfish. I also considered the Bloody Huge Flying Hedge-Trimmer, but statistical modeling ultimately proved that appellation to be approximately 16.67% +/- 1.3% less cool.

...Yeah, whatever. Well, okay then--what are we waiting for? It\'s time to take this thing for a spin around the block. Spool up the jet engines...


Fire up the first rocket engines...


It won\'t pull up until you hit 100 m/s. Coincidentally, this occurs right as you reach the end of the runway.


Kick in the remaining engines...


...and slowly pull back to 90 degrees.


Welcome to orbit!


100 km, in case you\'re wondering.


'We have a firing solution, the ship is locked on, and the entire Arsenal of Friendship is armed and ready. Your command?'

'Let Tampa live another day, Lieutenant.'


Well, that about wraps it up. Time to land.


Oh, you meant *on Kerbin*. Sorry.

Let\'s head back.




Okay, now it\'s time to go home.

Oops--could we make one more stop?


Thanks ever so much.


I just need to land here real quick. Won\'t be but a moment.







See? All done.


We\'ll be off again in a second, I just need to turn to bearing 090 for takeoff. That hill shouldn\'t get in the way, should it?


Oh, plenty of room.



No problem at all!


One maneuver later...



And we leave this strange place behind.


Let\'s go home!

Wait, as long as we\'re way out here...


Let\'s see just how high we *can* orbit Kerbin.


Great! Now a quick jaunt into interplanetary space...


On second thought, that\'s not such a great idea.



Even after reloading a save *before* entering interplanetary space, some glitches persisted and the frame rate slowed significantly.


Okay, NOW it\'s time for home. We\'re down to only 10 tanks of fuel, and we don\'t want to do anything risky this trip...

(and besides, Jeb\'s almost out of Mork and Mindy episodes.)

Time for some aerobraking...



Finally, the first real aerodynamic flight all trip.






Hey--tiny buildings in the distance!


Lining up...


And TOUCHDOWN of the space, whatever this thing is.


Thanks for watching!


(And yes, that was all done on one mission.)

If you decide to try the Sawfish for yourself, keep in mind that it handles quite poorly, due to limitations of stock parts and engine mechanics.

The plane would handle far, far better if it had a small number of front fins with a large range of motion, like +/- 45 degrees or more. Also, if the 'cockpit' was moved to the center of the craft, SAS mode would be far less jerky and less likely to flip the plane. And if rocket engines had a more realistic weight and jet engines could be mounted in the middle of the plane, the craft could be much better balanced and less likely to tip up.

As is, there\'s not much that can be done about it without making the ship significantly more complex and laggier.

If you\'ve got anything below a high-end Core 2, and preferably a good i5+ rig, don\'t bother. You can try it, but don\'t expect KSP to run smoothly.

Be sure to engage the first and second sets of engines during takeoff. You won\'t be able to lift off until you reach 100 m/s.

Make sure you keep your angle of attack inside +/- 20 degrees (stay within 20 degrees of the green circle on your navball) while in atmo, or else the canards start working against you and you\'re dead meat.

A joystick helps, not to mention the trim controls.

If you\'re using the keyboard for free flight and landing, adjust the trim down, keep SAS on and maneuver in short bursts while pressing the \'F\' key.

During takeoff, once you get the nose in the air it will tend to pitch up, so just keep SAS on and tap the \'F\' key to tilt up a few degrees at a time.

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Awesome or should I say sawsome sauce there pushingrobot, you have taken this challenge by the horns and completed every single additional kudos objective bar one... obviously you didnt get the minimalist record this time :P

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Thanks! I was actually surprised it could take the Kerbin Grand Tour on so little fuel. I had originally planned on adding a dozen or so more tanks, but they ended up causing lag (and were completely unnecessary).

The unwieldiness of the craft actually worked to my advantage--landing, especially on the Mun, had to be absolutely perfect.

I whittled my orbit down such that I was coming in almost perfectly horizontal, so I could retro burn without tipping the plane up past a safe landing angle. Of course, timing was critical; if I burned too late, I\'d careen of the surface, and if I burned too early, I\'d come to a stop a hundred meters up and then plummet to the ground. I failed about a dozen times before hitting on exactly the right altitude to fire the engines--exactly 300m above the surface (!). After a furious burn, the tail of the plane stopped just a few meters above the ground, and the RCS kept the nose from falling too fast. With a gentle bump, I was on the Mun.

And since the whole burn took all of fifteen seconds, it was an amazingly fuel efficient landing. I\'d love to see a landing computer in the final KSP, even if it\'s bulky or expensive; for larger craft, it\'s the difference between using two tanks of fuel for landing versus six or ten for a conservative hands-on approach.

Minmus was much easier thanks to the lower gravity (and orbit velocities). Don\'t attempt landing on the Mun until you\'ve tried it on Minmus a few times. I didn\'t time the Minmus retro burn quite as perfectly, but I didn\'t need to; it was easier to eyeball things, and falling 10 meters at the end did no damage.

The orbit changes themselves took very little fuel. Once you\'re past a few million meters above Kerbin, a tiny bit of delta-v goes a very long way. On a small craft, you could go from the Mun to Minmus to an escape trajectory on a fraction of a tank as long as you time your burns correctly.

For as impressive as the Sawfish\'s tour was, it actually burned less fuel (for its size) than a typical Mun lander. In terms of power/fuel ratio, the Sawfish is roughly equivalent to an engine with five fuel tanks on top. There\'s no reason you couldn\'t do the entire trip with a small rocket, as long as you time the burns just right. As Kan? Jigor? would say, 'Maximum Efficiency with Minimum Effort'.

Of course, it won\'t be as cool as the Sawfish, but that\'s like saying you\'re not as cool as the Fonz--it\'s just a fact of life. 8)

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By a pinky swear this went round kerbin but I will get a screeny of the orbit before I try to claim minimalist record. I believe it tots up at 10.64 (including gear) 8.64 if gear excluded...

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My smini2 SSTO spaceplaneplane

10.5 Tons

At launchpad.


At orbit.


Landed on runway.


Stock + Mechjeb.

to boolybooly

I put practicaly weigthless version of mechjeb/AR202 or radial/ to your Hopper 04.craft and it show in Ascent Autopilot 10.8 Tons.

It\'s easy way to measure ship mass.

But your Hooper 04 is capable get higer orbit than my first smini /because use of jet engine save some fuel/.

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OK thanks for checking Mager42. My adding up was out. You still have the minimalist title...

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If it really matters, I got the smini design down to 10.4 tons by removing the tailfin and canards, they were unnecessary with the vectoring from the lander engines, but to be honest my design is mostly plagiarism 8)

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I just went back and modified my separate-fuels spaceplane slightly, and was able to get a perfect success - with a kerbal-level stupid mistake at the end.

During takeoff gradually pitch-up to a 50 degree climb, at 10 km light the rockets, disable the jets just before they finish draining one tank. Once you\'re clear of the atmosphere the rockets can\'t be used at above 75% thrust without losing control, due to being off-center from the CoM.




remaining fuel in that picture is more than enough for a deorbit burn - burn it all or disable the rocket-fuel tanks before you re-enable the jets if you want to maintain fuel separation.


landed, throttle off, meant to hit the t key to disable the ASAS.. and hit G instead.


Even more images here.

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Despite my lack of spaceplane (or normal plane) design experience, I decided to try this challenge after seeing the Dreamchaser SSTO spaceplane on the spacecraft exchange. Thus was christened the TASD SSTO-SP 'Icarus'.

Following several design iterations just to have a successful takeoff, my first orbital flight was white-knuckle the whole way. A slight construction fail meant the fuel drained from the rear tanks first, which made the whole plane nose-heavy. This is especially fun around 30,000m, where ramjets or control surfaces are no help to the slow pitchdown.

After boucing twice between 20,000 to 35,000m I finally boosted into a 70km circular(-ish) orbit. Not one orbit later, I decided to deorbit. Despite my totally uninformed guess, I still managed to land on the same continent as KSC. Only clipped two of the engines on the first successful landing too. ;D

Pictures for the picture god:




A sudden design idea prompted me to swap the attachment point for the side fuel tanks to the back tank, which fixed some drainage issues and generally made the flight very enjoyable the whole way up. Managed to get into a 150km by 70km orbit with half a rocket tank to spare (hadn\'t even touched the main body tanks either ???)

Still haven\'t figured out how to land without clipping some engines. :o Shut up Bob, you\'re alive. That\'s what matters, right? :P

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Welp, once I heard about these space planes, I jumped right back into KSP!

I present to you the TJSP - 1/FS 'Berkut'.


The name is an acronym for 'Twin Jet Space Plane - 1/Forward Swept', and Berkut is a reference to the Russian Sukhoi Su-47 plane, which inspired my space plane. It weighs 24.17 tons, and takes to the sky when it drops off the end of the runway.

The first prototype used 3 Mk2 Fuselage parts instead of 4 FL-T500s, but it couldn\'t run the aerospike for long enough to get into space. The Berkut can run the rocket *just* long enough to get into orbit and de-orbit, and the turbojets for long enough to get to 15,000m, where I deactivate them, then long enough to adjust the course once back in the atmosphere.

I was trying to build a space plane all day long, but couldn\'t get it to work. This was the Berkut\'s maiden voyage, and I must say that she preformed splendidly.


Accelerating away from the runway.


A few seconds after I fired the aerospike rocket.


I was jumping up and down and clapping my hands like a little schoolgirl right about here.


I wish I could blame my irregular orbit on my rusty skills, but truth is I was never good at KSP. The orbit is roughly 230km x 250km.


Just chilling out in the final frontier.


My rocket engine ran out of fuel, so this would have to do.


Here she is back in the atmosphere, turning towards the runway, which is about 60km away.


Aaaaand there\'s the runway!


Originally, I wasn\'t going to bother trying to get anywhere near KSC, but since my re-entry brought me so close I decided 'why not?' This part had me worried, since I ran out of fuel at 5,000m with almost 40km to go.


Fortunately, I made it. Unfortunately, I\'m not used to gliding. I had already circled the runway twice, and was going in for a third when I dropped to the ground. You can see the runway behind the plane. Might could be I would have had more success if I had been using a joystick instead of my keyboard.


And finally, my stats for the mission.

Overall, I\'m very satisfied with this. I haven\'t even built a successful White Knight type craft yet, and I have a fully recoverable space plane.

Maybe I\'ll try to build a Mun worthy space plane next. :D

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