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jovan
05-14-2004, 05:44 AM
For the very first time in my life, I bought a DVD. They were selling 2001: A Space Odyssey for next to nothing and I thought: hey, what the heck.

Anyway, viewing the movie got me thinking about the problem of lunar airplanes.

How difficult would it be to design a vehicle that moves in a fashion similar to a regular airplane, but on the Moon? With no air, the problem seems quite non-trivial. What would be some ways a flying vehicle could be made for lunar use? (Low altitude.)

I'm thinking maybe, it's as simple as fitting a number of small downward-pointing rockets to offset the gravity. Would something like this work?

Mangetout
05-14-2004, 05:51 AM
It would be somewhat similar to the way VTOL jet aircraft (like the Harrier) work here on Earth - it is unstable, but an active balancing system can cope with it.

I say 'somewhat' similar, because unlike Earth, what you don't have is air that you can scoop up and throw downwards, so you'd have to carry your own reaction mass with you - I think this would severely limit the range and effectiveness of such a vehicle - ballistic transports might be more efficient.

Derleth
05-14-2004, 07:39 AM
You would indeed need to carry your reaction mass with you, which increases costs to astronomical levels (;)) for all but the shortest flights. It would be better to create ballistic transports for anything (anyone?) that doesn't mind a somewhat jolty ride. (However, Lunar gravity being as pitiful as it is, a rather gentler ride might be achieved with judicious use of small rockets out the front and back ends of a bullet craft.)

Of course, the `bullet' would be a small box in shape, assuming people still have intelligence when these things are designed. :D Without atmospheric drag, no particular shape is needed to be efficient, so a box wins out because it's easy to shove cargo into.

For safety's sake, however, a route protected by thick rock might be indicated. A look at the pockmarked face of our close neighbor should be all the argument this point needs.

As for Lunar aircraft: The Lunar landing module of the Apollo days did a pretty good impersonation of a small helicopter, even travelling around to find a good place for Tranquility Base, so our basic engineering is done. It would be expensive as all hell, as I've said, but who can put a price on cool?

CurtC
05-14-2004, 08:30 AM
Derleth wrote:
Without atmospheric drag, no particular shape is needed to be efficient, so a box wins out because it's easy to shove cargo into.Except if it needs to be pressurized, a round shape is better.

Derleth
05-14-2004, 08:57 AM
Except if it needs to be pressurized, a round shape is better. True, and I didn't think of that.