QUESTION:
How does the Rover know how to get back to the Pathfinder when it leaves?
How do you make it know?

ANSWER from Guy Beutelschies on May 14, 1997:
The Rover is programmed to frequently stop and communicate with the Lander
whenever it is driving. We call this a heartbeat. If the heartbeat fails
(if the Rover has gone too far away from the Lander for it's radio to
work), the Rover will retrace it's last steps and eventually drive back to
where it can reestablish communications.

Matt Wallace - Rover Operations Coordinator