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Is it possible that a multi-rotor polycopter of some kind could escape Mars' atmosphere from its own propulsion?

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migrated from astronomy.stackexchange.com Jul 5 '17 at 12:31

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    $\begingroup$ Probably better for Space-ex than here. I also don't think Ion thrusters are good for escaping a planet. They're good when you're already in space. To fly off Mars, the ship would likely need chemical fuel like a standard rocket. (or Nuclear if they go that rout). $\endgroup$ – userLTK Jul 5 '17 at 0:51
  • $\begingroup$ When I said "propel" I meant by the thrust of the drone itself, not ion thrusters. Notice that I said "out of orbit" and then after that I said "ion thrust back". $\endgroup$ – user20289 Jul 5 '17 at 18:17
  • $\begingroup$ I thought the title conveyed the idea pretty clearly that the escape would be done from the drone. As far as I am aware there are no ion thrusted drones. Just saying. $\endgroup$ – user20289 Jul 5 '17 at 18:27
  • $\begingroup$ If I understand your question right, then you might want to have a look at this. what-if.xkcd.com/58 You still need to reach escape velocity. 5 km/s relative to the surface, or about 11,000 mph. $\endgroup$ – userLTK Jul 5 '17 at 18:53
  • $\begingroup$ The atmosphere limits the maximum speed of the drone to a value far below the escape velocity or orbit velocity. If the pressure of the atmosphere decreases with increasing hight, the lift force of the drone decreases until the maximum height of the drone is reached. At this maximum height, there is still a lot of remaining atmosphere above the drone. There is no drone that could fly in a vacuum, the rotor count does not help. $\endgroup$ – Uwe Jul 5 '17 at 22:14
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Reaching orbit using aerodynamic lift from a rotor like an Earth-based drone is likely impossible. The atmosphere on Mars is very thin compared to Earth (by about a factor of 100!) so lift is much harder to achieve. At best, you'd be able to do short hops, but nowhere near orbital speed.

That said, a powerful enough launch vehicle could be equipped on a lander for a sample return mission. However, it would have to use conventional rocket engines to have enough thrust.

A sample return is in fact one of the proposed requirements for the NASA Mars 2020 Rover and has been discussed for other missions.

The launch vehicle for sample return would need about 4.1 km/s of delta V to reach orbit from the Martian surface. It's possible it would then perform a rendezvous with another transfer vehicle, which would occur once in orbit for the retrieval capsule.


Related question with more information: Could a helicopter fly on Mars?

Check out this video for helicopter-like test in a simulated Martian atmosphere:

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  • $\begingroup$ When I said "propel" I meant via the drone itself, i.e., the propulsion is provided from a multirotor polycopter of some kind. Ion thrusters would be equipped for post-atmospheric exit. $\endgroup$ – user20289 Jul 5 '17 at 18:25
  • $\begingroup$ Hey @uwnojpjm, I've edited my post in relation to a rotor-based propelling system. Sadly, it won't fare much better than an ion system, but at least gives you some surface mobility. The low atmosphere density really makes it tough to gain much speed, and the majority of what's needed for orbit is horizontal speed. $\endgroup$ – Sarah Bailey Jul 5 '17 at 18:40

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