Was thinking about our Mars rovers the other day, and wondering…is it possible for NASA to put small helicopters or other small flying drones on the rovers? We have the technology now to have small helicopter type machines that can autonomously launch, fly about and video terrain, and land (back on the rover), so it would certainly be useful for scouting paths for future rovers, or just basically getting a better look around the terrain that the rover is going though. And since weight is an issue, these things can be really small and light weight. But with the thin Martian atmosphere, maybe it’s not feasible? What would it take for a small helicopter to fly on Mars? What about some other small flying vehicle? Maybe some sort of balloon (or one of those small blimp-like drones with small fans to move it around)?
Helicopters wouldn’t work because of the very thin atmosphere. The surface atmosphere on Mars is still way thinner than the highest altitudes that helicopters can achieve on earth. You can’t just make light, simple helicopters either. They are complex machines by their very nature and not very energy efficient.
Helium balloons would probably work but what do you really gain? The Curiosity lander was a rocket version of this idea but it was for one-time use only. It took aerial photos during landing already.
The air pressure on Mars is about the same as the air pressure on Earth at 150,000 feet. That’s far higher than the highest conventional airplanes or helicopters have flown.
The atmosphere on Mars is about 100,000 foot level… pretty much nothing compared to earth. Most flying dvices won’t work.
Balloons (a) would need to be big and (b) need to be refilled. helium is hard to find and leaks easily since in is monatomic (one atom) so escapes containment easily. The rover would have a few refills, then, that’s it.
Maybe it could use a catapult or something and fling a camera into the sky; but then it would not get very high so what kind of extra data do you get, and it would then risk getting lost in an inaccessible place, plus extra detours to retreive it.
No oxygen to combine with for Hindenburg Effects… Why not use Hydrogen in the suggested balloons? Lighter then Helium, and less prone to leakage (being a di-atomic molecule.)
Since no one seems to be stepping up to the plate, let me state that the atmosphere on Mars is very thin-- too thin for conventional helicopters to operate.
You could use balloons, but because the atmosphere is so thin, you’d need a tremendous amount of balloon to lift a similar amount of weight compared to earth. Mars’s low gravity doesn’t help you in this instance, because in order to be lighter than air, lightening your balloon doesn’t help if you lighten the air you’re floating in by the same amount. Consider that balloon skydiving guy a month or two ago-- he jumped from about 120,000 feet. That’s your ground-level starting point on Mars. It only gets thinner from there.
With such a thin atmosphere, a relatively low orbit satellite would seem like a better plan for aerial shots. Being outside the atmosphere would allow it to last much longer as it would need only small amounts of power to maintain its orbit, and could deploy significant solar panels for power generation without worrying about the aerodynamics. MRO fits the bill pretty well at about 300km altitude with a resolution of .3m. You could go a bit lower - exosphere starts at about 200km - but the drag problems are probably significant enough that you’re better off improving camera technology instead.
I’ve seen proposals for hot air balloons on Mars. The idea isn’t so much to get data during the flight itself (though I’m sure that would be done, too), but to move the lander long distances from one site to another for science on the surface. Yes, we have rovers that can move about, but they’re incredibly slow.
For a heavier-than-air craft, like a helicopter or an airplane, yes, it would. For a lighter than air craft, like a balloon, no, it wouldn’t. Imagine a boat on an ocean on Mars-- it would float exactly the same amount on Mars as it would on Earth. That’s all a balloon is doing: floating.
You have to remember, the air on Mars is not Denver thin, or Quito thin, or even Mt. Everest thin. It’s about .5% of the pressure on Earth. So your helicopter only has to generate 1/3 the lift to lift off compared to Earth, but it’s got less than 1/200th the atmosphere to do it with.
EDIT: If you want to balloon through a planet’s atmosphere, your best bet is Venus. It’s got an atmosphere about 90 times as dense as the Earth’s, so you can float one hell of a balloon. On the other hand, it’s hotter than an oven and very corrosive.
If you want a hydrogen balloon - you need hydrogen. If you vent it to land, you need more next time; or else, you are working imprecisely as you compress/ pump the hydrogen back into the tank. How do you replenish? OTOH, the atmosphere is CO2, not O2/N2 like earth, so a bit denser. Hot air balloon might work - but then you need a LOT of heat. Pumps or heat, you need a lot of energy. a nuclear reactor might work, but bigger batteries or a nuclear reactor for a light flying machine leads to engineering contradictions.
Yes, the whole system is lighter due to low gravity, but then the weight differential between a litre of CO2 vs. H2 is that much less too.
To clarify, the Mars atmosphere is about the equivalent of the earth atmosphere at about 100,000 feet above sea level. Aircraft that maneuver at that altitude (pretty much none) compensate for lack of lift with extreme speed - not really an option for trying to land.
Anyway, thanks for the comments.