> Yes, helicopters can't fly at extremely high altitudes because their rotor blades need dense air to generate lift, On Mars atmosphere is about 1%, or close.

> Yes, helicopters can't fly at extremely high altitudes because their rotor blades need dense air to generate lift, On Mars atmosphere is about 1%, or close. Still helicopter did fly. Correctly saying 'helicopters designed for dense atmosphere cannot fly in thin'. It is possible to build a drone specifically for these cases. Which will be able to lift 200kg off Everest. With long, wide blades. It's not that expensive and not a rocket science onymore.