All NASA Mars Orbiter-Lander Missions

Paired missions in which NASA sent an orbiter and a lander to Mars together, the orbiter surveying the planet and relaying data while the lander touched down to study the surface. The group is led by the two Viking spacecraft of the 1970s, whose landers were the first to operate successfully on Mars. A mission belongs here when its cited source describes a NASA spacecraft consisting of an orbiter and a lander. The Soviet orbiter and lander probes of the Mars program form a separate group in the same subcategory.