QUESTION:
NASA TechBriefs September 1995 Volume 19 Number 9 Page 60 has an article
titled Miniature Radioisotope Power Source. It is a battery, thermopile, RTG
unit. My question is, could a unit such as this be used for the Rover? If
not, why not? It would seem to be a perfect system to deal with the no
sunlight/low temperature problem.

ANSWER from David Dubov:
The efficiency of the miniature radioisotope power source is less than 10%;
that is, a 1W heating radioisotope source would produce less than 0.1W of
electrical power. A significant amount of radioisotope material would be
required to meet the nightime power needs of the rover which range from 1W
to 6W depending on the operation.