The Rover Arm enables instruments to extend, bend, and be
placed precisely against a rock, grinding away layers, taking
microscopic images, and analyzing the elemental composition
of the rocks and soil. A Mast assembly on a Rover serves two
purposes. Firstly it enables a rover to see in the distance,
giving it a human-scale view of its surroundings,
and secondly it acts as a periscope for instruments enabling
them to take atmospheric samples.