Mars Pathfinder
The Mars Pathfider, launched in 1996, was a hugely successful Mars exploration probe.
The probe consisted of a lander and of a wheeled robot called Sojourner. The lander relayed transmissions to and from the robot, allowing it to operate independently of the probe body. The robot was remotely controlled, but had a limited intelligence allowing it to negotiate minor obstacles without operator intervention.
The robot freedom of movement allowed the exploration team to closely analyze many more rocks and soil samples than a traditional probe. An on-board camera was used for navigation and to take many stunning pictures of the Mars environment.