What about an airship using hydrogen left over from methane production. Explosion or fire might be limited due to no oxygen in the Martian atmosphere. One would only have to worry about high winds.
Possible - sure! The atmospheric pressure of Mars corresponds to about 31-34 km in Earths atmosphere which is comfortably within the capabilities of high altitude balloons ..
For aircraft, how about rockets for VTOL and acceleration, with solar powered props and long, thin wings for cruise?
KelvinZero, eriblo is incorrect...This calculator shows the pressure at 31km in Earth's atmosphere to be 1.20896 kPa, which is still twice the average pressure on the Martian surface of 0.6kPa.Keep in mind that is your starting pressure at the surface. You do not want a buoyancy based ship cruising around at surface altitude; you want to be at some altitude for safety. As soon as you begin ascending, that pressure begins to drop sharply, causing your lighter than air craft to begin losing buoyancy almost immediately.Re. your comments: How would you keep that hydrogen hot? Also, those balloons that go to extreme altitudes on Earth are only able to carry payloads that are relatively low mass; on Mars you are going to be severely mass constrained. Further, what would you use for propulsion? (Consider the mass of the propulsion source and fuel.)
Hey, random idea.Would a very large wing be able to exploit some sort of ground effect that would be impractical on earth?My argument is that although you would have to fly very fast, very close to the ground, the almost-vacuum atmosphere on Mars might make this sort of flying more predictable than on earth, where you can be thrown around by stray gusts. You would never be surprised by a big rock either. The route would be extensively mapped.
With a Lithium-CO2 battery (or possibly a CO/O2 fuel cell) and an efficient airframe (think of a glider) you could get all the way to the other side of the planet on a single charge.The main difficulty is landing. Landing speed would have to be very high due to the thin air. A cart on rails, a zip line, or perhaps a fast ground vehicle could be used to launch and recover the aircraft.Otherwise you need to perfect vertical takeoff, vertical landing with either very high power motors and huge propellers or use rockets just for takeoff and landing. Since the rockets only need about 200m/s delta-V, you won't need much propellant per flight.VTOL combined with high efficiency electric flight is my preferred method, but would be hard to develop.
Ive thought of a ground effect wing for Mars. But it's have to be huge to get the benefit because you'd have to fly high enough not to hit boulders. So not practical unless you could move all the boulders out of the way.
Since a subsonic Mars plane of sufficient size to transport humans would need very long wings anyway, I wonder if it would be possible to generate enough lift that way to fly a reasonable payload.