Klapaucius

Duna rocket-powered aircraft endurance challenge

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Due to a major financial scandal, Kerbin's main supplier of prop engines can no longer deliver. The timing could not be worse as KSP is launching a new Duna programme, with a focus on exploratory aircraft that can deliver good science.  Plans are afoot for serious fuel mining and processing infrastructure, but this is still costly in time and resources. Creating multiple fuel stations around the planet is not viable at this time.  They need an aircraft with range.  

 

 

The challenge:

Build an aircraft for Duna, and fly it as far as you can with the fuel you are carrying.  The winner is the one who flies the farthest.

The only rules are:

 

1. It must be rocket powered. No props or Kethane-powered mod jets .

2. It must carry a Mobile Processing Lab.

3. It must not go into orbit. Ceiling is 16,000 meters.

4. No drop tanks.  Too expensive to replace and/or recover.

5. It must be a real plane, meaning it has lift and could take off and land multiple times.

6. Mods are fine, but the engines must be stock.

 

Details:

Cheat or Mission Builder yourself to any location on Duna. Fly your plane as far as you can, and when you land, hit F3 to show your total distance traveled.

Any mods (other than mod engines) are fine except infinite fuel or anything that breaks the spirit of the challenge. Mods and stock parts will be two different categories. A plane is considered stock if it has no modded parts. Non-parts mods have no bearing on that.

Your plane can be as big or small as you want it.  It can have tons of stability enhancements or none at all. It can be piloted or probe cored, but you must have a full science crew in the lab. I suppose a really keen person could build a flying fuel processor and go forever (and serious kudos if they do), but the spirit of the challenge is single flight range and that is what you will be judged on.

 

This idea came about while I was tooling around in Mission Builder, modifying a plane I built for Kerbin to see what I could do. I got a fair distance (well, for me, anyway) and I thought it would be cool to see how others solve this problem.  Partly this is selfish; I want to learn from you all :-)  

On my to-do list for work is to get upskilled in Adobe Illustrator. It may take a bit, but I will create a badge for this challenge.

 

My first attempt with the lab. Okay, but needs a lot of R&D. 

a95kmlp.png

 

 

Edited by Klapaucius

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Flying on Duna calls for lots of wing wings and a bit of NTR power, right? Once more, SXT to the rescue:

duna_flyer-1.jpg Huge wings (each amounting to 6 stock airliner wings), a sleek 2.5m cockpit, and LF-only tanks in the fuselage. Cargo bay holds mining equipment and a science package. The center engine is non-stock, SXT's upscaled rapier, thus violating the letter (though I hope not the spirit) of this challenge.

It can take off from Kerbin and go to Duna under it's own power, doing science left and right, and refuel as often as you want it to. So, it could serve as a single-stage-to-many-places, but fuel capacity is excessive while TWR is rather low.

Be that as it may, with full tanks it masses 120t and cannot take off on Duna under nuclear power alone. Takeoff speed is estimated to be somewhere on the order of 400m/s, acceleration slightly over 1m/s²... if someone finds a ten-mile runway on Duna, please let me know. I just used the forbidden engine for a short and decisive takeoff, under the assumption that ultimately it doesn't matter (there's plenty of stock engines that could outperform the part I've been using).

Anyway, here she is in level flight:

duna_flyer-2.jpg

I've angled the wings so "zero" AoA is anything but. It took me about eight minutes of full thrust to get there in the first place, but now I can throttle down and cruise for hours. Please forgive me for not sitting through it.

However, I'm not sure if this still qualifies as "flight": at this point, orbital forces already overpower aerodynamics.

 

 

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15 hours ago, Laie said:

The center engine is non-stock, SXT's upscaled rapier, thus violating the letter (though I hope not the spirit) of this challenge.

That's not really an issue since it is only getting you up to speed. What I was trying to avoid were The main thing was to see how far we could get burning fuel.

 

15 hours ago, Laie said:

It can take off from Kerbin and go to Duna under it's own power, doing science left and right, and refuel as often as you want it to. So, it could serve as a single-stage-to-many-places, but fuel capacity is excessive while TWR is rather low.

Be that as it may, with full tanks it masses 120t and cannot take off on Duna under nuclear power alone. Takeoff speed is estimated to be somewhere on the order of 400m/s, acceleration slightly over 1m/s²... if someone finds a ten-mile runway on Duna, please let me know. I just used the forbidden engine for a short and decisive takeoff, under the assumption that ultimately it doesn't matter (there's plenty of stock engines that could outperform the part I've been using).

 

I did not even think of the nuke engines. In a way, not what I was thinking of concerning endurance, so perhaps not really in the spirit of the challenge. But that's my own fault for not thinking this through well enough.  But...having said that, this is exactly the type of building technique tips and learning I was hoping for :-)

 

15 hours ago, Laie said:

However, I'm not sure if this still qualifies as "flight": at this point, orbital forces already overpower aerodynamics.

I was not sure what to set the ceiling at to be honest.  I kind of went for a compromise between a bit of headroom and still having some atmosphere.

 

Anyway, thanks for posting! 

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9 hours ago, Klapaucius said:

I did not even think of the nuke engines. In a way, not what I was thinking of concerning endurance, so perhaps not really in the spirit of the challenge.

Come again? "Endurance plane" calls for the most efficient engines available, and besides, all those wings provide  "free" LF-only storage that I, for one, won't let go unused.

On 7/15/2018 at 6:44 PM, Laie said:

However, I'm not sure if this still qualifies as "flight": at this point, orbital forces already overpower aerodynamics.

9 hours ago, Klapaucius said:

I was not sure what to set the ceiling at to be honest.  I kind of went for a compromise between a bit of headroom and still having some atmosphere.

Well... I suspect you were looking for a biome-hopper, and if so, the challenge should have been written as such. A lot of the cost comes with takeoff and ascent -- notice how I spent about a quarter of my propellant to get to cruising altitude in the first place? Looking at Duna's biome map, I suspect that the majority of flights don't require tremendous range, and so getting up to "ideal" cruising altitude and airspeed (which, in kerbal errordynamics, is as high and fast as possible) would be wasteful.

EDIT:

duna_flyer-3.jpg

OK, for good measure... leaving the tanks and rapier engine at home, the plane becomes half as massive and can take off easily. Originally I was cruising at 5km but then had to climb for a mountain. At this airspeed and altitude, it can keep going for more than 30 minutes. There's still not only a lab but a full refinery as well -- I guess it would take two or (at most) three fuel stops to visit every single biome on Duna.

Craft files available. (requires SXT, of course, but I don't think anything else)

Edited by Laie

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1 hour ago, Laie said:

Come again? "Endurance plane" calls for the most efficient engines available, and besides, all those wings provide  "free" LF-only storage that I, for one, won't let go unused.

Well... I suspect you were looking for a biome-hopper, and if so, the challenge should have been written as such. A lot of the cost comes with takeoff and ascent -- notice how I spent about a quarter of my propellant to get to cruising altitude in the first place? Looking at Duna's biome map, I suspect that the majority of flights don't require tremendous range, and so getting up to "ideal" cruising altitude and airspeed (which, in kerbal errordynamics, is as high and fast as possible) would be wasteful.

Fair comments. I was just trying to see what folks could pull off with the standard rocket engines. This was somewhat of a contrived design problem as a challenge--like making the heaviest plane that will fly with a Juno.  But, as someone just venturing out into the solar system having spent a lot of time building aircraft on Kerbin, I put up a challenge that in a way reflected my own challenges.  Anyway, thanks for responding.

BTW: I did not know the nuclear engines were liquid only.  I almost always use wing tanks on my regular planes for the reason you cited above. There is so much to learn in this game.  Again, thanks :)

Edited by Klapaucius

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