Luna 17 and 21
Luna 17 and Luna 21 were the two Soviet lunar landers that delivered the two Lunokhod rovers in 1971 and 1973. Originally designed to support the Soviet human Moon missions, they were repurposed for fully robotic explorations, the first ones to move on the surface of an extraterrestrial body. Although both lost contact with Earth at the end of their missions, the retroreflectors mounted on top of the rovers is still used to this day, primarily to precisely measure the distance of the Moon from the Earth.
Luna 17 imaged by Lunokhod 1, 1970
Mare Imbrium as seen by Lunokhod 1, 1970
The rim of Le Monnier crater as seen by Lunokhod 2, 1973
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