Eve minimal fuel surface ascent mission concept

[mstachowsky]

I'm trying to design a lander/plane for an Eve surface return mission. My goal is to use the smallest possible plane to do this. Since I'll have to rely on rocket thrust to get the plane into the atmosphere, it would be grand if I could do the following:

1) Land without using any fuel

2) Take off using tiny engines, say two 30KN thrust ones, with as small a fuel tank as I can for each

3) Use the wings of the plane to get me *as high into the atmosphere as possible* using those two engines

4) Once the apogee (apoeve?) is reached in my suborbital atmospheric flight, drop the wings and ignite the second stage to do the large majority of the orbital insertion

5) If this is still impossible, I'll probably make the final stage an ion powered, very light booster that can get to orbit.

I feel that this task should be possible with a very small spaceplane, rather than the "MOAR FUEL" rockets I've seen for most Eve return missions. I want to know how to compute the delta-v to orbit from a given height in Eve's atmosphere, so that I can figure out the best design to use. It's a big trade-off between the first stage, powered by rockets whose sole purpose is to get my high into the atmosphere, and the final stage, which needs to be orbital.

Any thoughts? Does anyone think my idea is possible?

[Pecan]

The big advantage of planes on Kerbin (and Laythe) is that they can use very fuel-efficient jets. This does not apply in Eve's atmosphere which has no oxygen. That just leaves the wings for lift and they are usually not worth their mass - you're better off with a conventional rocket launch.

There is no way to compute the deltaV requirements in an atmosphere and especially using wings since so much depends on the vehicle's TWR, your ascent profile, drag, etc. etc. You may like to look at http://forum.kerbalspaceprogram.com/threads/76153-Lightest-Eve-Lander for what other people have done.

[MockKnizzle]

A rocketplane on Eve is generally a terrible idea, since you're gonna spend even longer inside the soupy atmosphere than a normal launch, and your rocket engines are gonna be getting terrible Isp the entire time. You could just maybe get away with it if you're using a Kethane turbine, but otherwise it's not going to get anywhere.

[Hans Dorn]

EVERYTHING is a terrible idea on Eve, IME...

[cantab]

Yeah, rockets are essentially least useful at low speeds, and an Eve plane is not going to be fast. The only way I can see it working is if you can get airborne with very little thrust, but I'm not sure if KSP aerodynamics works that way.

The Wiki page on Eve lists some typical delta-V figures for rocket ascents, though only from heights where there's land.

[Merinsan]

The only way I can see this working is if you could use ion engines for the first stage.

The problem is, you will probably need a lot more thrust.

[peadar1987]

Or if you don't mind using mods, download firespitter or hooligan labs airships (they both have loads of parts, so you might want to delete any you're not using to save memory).

Firespitter has electrically powered propellers you can use to get a plane up to a pretty high altitude without using any fuel, and hooligan has huge big balloons that can perform the same function.

[Alfondoo]

I tried once, the only possible way that isn't quite cheaty (airships) is with Kethane Jets, this is also really hard if you want to keep the size down. I did see someone do it with rocket engines but the plane was so big it may as well have been a rocket.

This is what I ended up with back in 0.21, I might have another go as I'm a wee bit more experienced now.

[Redshift OTF]

If a rocket plane on Kerbin uses more fuel to get into space than a standard rocket then I think the same would apply to Eve. It would look cool though!

[KerbMav]

Solar powered propeller plane?

[magnemoe]

Solar powered propeller plane?

Would work for first stage as it will take you out of the soup atmosphere, you will still need 4km/s or more to get into orbit, however this require an far smaller upper stage, it might even be posible to make it ssto as the electrical engines and wings are pretty lightweight.

[Moon Goddess]

A balloon is the best thing for Eve, get up into the upper atmo, fire your rockets and drop the balloon once you get out of the soup.

[Frank_G]

I built a helicopter with rocket engines attached using the firespitter mod. You can get it easily into orbit as the helicopter only uses electricity and gets you very high in that dense soup. I havent attempted a stock launch yet. Another open challenge that needs to be attended to.