Given the differences in both gravity and atmospheric density, what kind of airframe would be most advantageous, do you think, for Mars or Titan? Balloons or other lighter-than-air craft are an obvious solution, but I'm thinking more in terms of fixed-wing aircraft right now.

For Mars, I'm thinking something with very low wing loading, and probably a very wide wingspan - something like the U-2/TR-1, or Voyager, to try to get as much lift as possible out of the thin atmosphere.

What about Titan, though? It's low gravity, but has a very dense atmosphere. Would we mainly be looking at short wingspans, high wing-loading and minimal frontal surface area, to cut down on drag?

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Sleep? Isn't that that totally inadaquate substitute for caffeine I've heard so much about?

Quantumfoamy.com, my astronomy/astrophotography blog.