Concept
Lunokhod 1 (Russian: Луноход-1 ("Moonwalker 1"), also known as Аппарат 8ЕЛ No 203 ("Device 8EL No. 203") was the first of two robotic lunar rovers landed on the Moon by the Soviet Union as part of its Lunokhod program. The Luna 17 spacecraft carried Lunokhod 1 to the Moon in 1970. Lunokhod 1 was the first remote-controlled robot "rover" to freely move across the surface of an astronomical object beyond the Earth. It was also the first wheeled craft on another celestial body. Lunokhod 0 (No.201), the previous and first attempt to do so, launched in February 1969 but failed to reach orbit. Although only designed for a lifetime of three lunar days (approximately three Earth months), Lunokhod 1 operated on the lunar surface for eleven lunar days (321 Earth days) and traversed a total distance of 10.54 km. Lunokhod 1 was a lunar vehicle formed of a tub-like compartment with a large convex lid on eight independently powered wheels. Its length was . Lunokhod 1 was equipped with a cone-shaped antenna, a highly directional helical antenna, four television cameras, and special extendable devices to test the lunar soil for soil density and mechanical properties. An X-ray spectrometer, an X-ray telescope, cosmic ray detectors, and a laser retro-reflector (supplied by France) were also included. The vehicle was powered by batteries which were recharged during the lunar day by a solar cell array mounted on the underside of the lid. To be able to work in a vacuum, special fluoride-based lubricant was used for the mechanical parts, and the electric motors (one in each wheel hub) were enclosed in pressurized containers. During the lunar nights, the lid was closed, and a polonium-210 radioisotope heater unit kept the internal components at operating temperature. Lunokhod 1 was intended to operate through three lunar days (approximately three Earth months), but actually operated for eleven lunar days. Luna 17 was launched on November 10, 1970 at 14:44:01 UTC.
