QUESTION:
You are already considering and designing the next mission to Mars.  I would
like to make a suggestion and receve your input.  Would it be possible to
send a flying machine like a helichopter or a glider that can scan the
surface of mars.  Rockets could carry the glider to a height so it could
glise slowly to the ground collecting weather, surface-aerial still and
motion pictures and sending them to the lander.  It might also drop a small
payload miles from the lander.

ANSWER from Donna Shirley on August 3, 1997:
Mars balloons and airplanes are indeed being studied for future
missions, although a specific mission using them is not yet planned.
Helicopters are a problem because the rotor tips must be very supersonic in
the thin atmosphere, and that quickly leads to destruction of the rotors
through cavitation.

ANSWER from Bruce Jakosky on July 7, 1997:
Even though the Martian atmosphere is so much thinner than the Earth's
atmosphere, an unmanned airplane still could fly through it.  It would have
to be a small, lightweight plane, but it is possible.  Some scientists are
planning future missions to Mars that would use scientific instruments
mounted on board an airplane; this would allow them to visit a wide variety
of places on the surface.