QUESTION:
Once the rover's batteries are used, what operations are still possible
using only the rover's solar arrays?

ANSWER from David Dubov:
The rover can perform all planned operations (e.g., driving, communicating,
imaging) under solar panel power alone. In this condition (without
batteries) some care must be taken to schedule rover operations at times of
the day where solar panel production exceeds planned utilization to allow
adequate margins to avoid 'brown-outs'. In addition, terrain which creates
the potential for array shading must be treated as hazards for the vehicle.

Of course, night time wakeups will no longer be possible once batteries are
depleted. Measurements from our science instrument (the APXS) must be
scheduled during the day (rather than at night). This would mean some rover
days dedicated to APXS measurements which can take up to 10 hours to gather.