Designing planes for non-Kerbin atmospheres?

[rofltehcat]

I'm thinking about making a glider for Duna instead of the "hopper" ("rocketchairs") I use to get around on atmosphere-less bodies in lieu of rovers (rovers really suck in this game). Is there anything I need to do differently compared to Kerbin plane design? It doesn't need to be very fast nor fly very high, it just needs to be stable in the air and easy to land (also, take off). I was thinking of powering it with 1-2 Spark engines or a Terrier. Do I need more/less wing area? Do I need to change how far my CoL and CoM are from each other? More or less control surfaces?

Edited July 15, 2015 by rofltehcat

[Sharpy]

Definitely more wing area. Less dense air = less lift.

[ygarl]

Gliders are a good thing here. Perhaps create two very long wings with double docking ports on the wing roots (to make sure they can only attach one way) and fly them into space separately, and connect them to your fuselage in orbit...

(Wow - now I want to try that, but I'm in the middle of a career game at the Mun/Minimus stage...)

[Teilnehmer]

Sparks and Teriers are good for short-range planes (Sparks are a bit better in Duna’s atmosphere).

Nerves are good for heavy long-range planes. Dawns  for light long-range planes.

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BTW, has anyone created planes for Eve in 1.0.x?

I suppose Aerospikes should be used there.

[eddiew]

Pretty sure Eve is impractical. It's so much of a soup that it's hard to get even a wingless object to move through it. Add on some lift surfaces and you burn your fuel in no time just trying to get above 100m/s.

[cantab]

If you want to fly slowly enough that landing and takeoff is safe, on Duna you'll need lots of lift or a vertical or short takeoff system.

You can test it on Kerbin anyway, take your design up to an altitude where the air pressure is similar to Duna's surface, and if possible lighten it (eg by short-fuelling) to simulate Duna's lesser gravity.

Don't forget to consider how you will get it on to Duna in the first place.

[Coga19000]

Despite popular opinion, gliders are actually pretty practical in Eve's atmosphere; I love using them there. It is true that it takes much fuel to take off, however, so the best plan for SCIENCE! *ahem* is to get it off its fairing at around 10 kilometers (you can try reentering with the glider itself, but only if you feel REALLY confident about the design) and start cruising above the biomes until you find a high enough mountain to land on (I think they go up to 9 kilometers, so you can find some spots with sufferable air density) If you decide to land on some low plains, and your engines are not efficient enough, you should also give it some minor rover capability (I can feel you, bro, but sometimes the boring way is the way to go)

Now, as regards design in general, Eve needs more powerful engines for takeoff but increased lift and drag means you need a smaller wingspan (but if you plan on reentering with it, you might need some extra area ruling to decelerate quicker... And lots more RCS RCS)

On Duna, the opposite is generally true; you need much bigger wings than usual to induce sufficient lift, and more control sufaces to get the same torque, which will however produce more drag (you might aso opt out for RCS of you don't manage to strike a balance otherwise) Because of low gravity and air pressure, Sparks will work just fine, unless you need the plane for long ranges. Otherwise, go for Nervs or PB-IONs as mentioned by others. Reentering is a breeze on Duna, even more with lift surfaces, so just throw it in there (which is fortunate, because there is no way you can fit Duna capable wings in a fairing that doesn't look ridiculous)

And your final target for gliders is of course Kerbin! Just kidding, just kidding...

Except that I'm not.

Laythe is the dream of every single green -skinned spaceplane engineer around. Reentry is very similar, so you should trust your plane for it only slightly less than you would for Kerbin entry (aerobrake at Jool velocities notwithstanding). The air density, terrain altitudes and gravity are so similar you don't even need a specialised craft; just get any Kerbal Airlines plane, stick it in top of a Jool-capable rocket, and cruise Laythe to your heart's content - even your bloody jet engines will work!

[Jaeleth]

I have used rovers extensively and yes, they are boring, as in real life, since they are slow... But they do cover a lot of ground with no fuel waste and accomplish multiple site sampling missions perfectly. I try to use as tiny rovers as I can and spread a lot of them on the planet's surface so that there's a chance to re-use one of them on the next contract.

Anyway, the trick for rovers is mechjeb. I never needed mechjeb to fly my ships but after having a couple of accidents while falling asleep driving my rovers I decided to install it. Do it, it will make rovers much more usable.

As for the topic. CoM and CoL relationship should remain the same anywhere in the universe, in thinner atmospheres go for bigger wings, testing in higher kerbin atmosphere, as mentioned is a very good idea. Pay attention to the slowest speed you can fly at high altitude, this will be your landing speed at Duna, if above 60m/s advice bigger wings or VTOL capabilities or chute, if your engineer on duna can refit them. Bigger wings difficult to lift off kerbin so you may want to make longer wings instead of increasing the wingspan. As for eve, aerospikes, a big plane, lsmall wings, lots of fuel and a network of mining stations, strategically placed, should do the job

in duna you could consider ion engines, but since xenon cannot be mined, xenon switched from prime fuel for small long endurance craft in 0.9 to expensive junk in 1.0 onwards. Why should I build a craft that needs fuel to be ferried from a million miles away every time it runs out when i can mine other type of fuel right on the spot?...

Edited July 15, 2015 by Jaeleth