Toward remotely controlled planetary rovers.

Studies of unmanned planetary rovers have emphasized a Mars mission. Relatively simple rovers, weighing about 50 kg and tethered to the lander, may precede semiautonomous roving vehicles. It is conceivable that the USSR will deploy a rover on Mars before Viking lands. The feasibility of the roving vehicle as an explorational tool hinges on its ability to operate for extended periods of time relatively independent of earth, to withstand the harshness of the Martian environment, and to travel hundreds of kilometers independent of the spacecraft that delivers it.