QUESTION:
What type of power source will be used to run the vehicles once they are in
Mars' orbit?

ANSWER from Charles Whetsel on February 17, 1997:
The Mars Global Surveyor Spacecraft is primarily a solar powered vehicle.
When we reach the final mapping orbit, our spacecraft is in a 2 hour orbit.
In each 2 hour orbit, we spend appr. 1 hour and 20 minutes in the daylight
and 40 minutes in the dark shadow behind Mars.  During the 40 minute
eclipse, we operate on battery power.  During the 1:20 daylight arc, we use
the solar arrays to generate not only enough electricity to power the
spacecraft, but also enough to fully recharge the batteries before we reach
the next eclipse.

Charles Whetsel
Project Engineer
Mars Surveyor Operations