First lunar/planetary rover

The first exploration rover to operate on another celestial body was the Soviet Union's Lunokhod 1, which soft-landed on the Moon on 17 November 1970. The solar-powered rover was originally scheduled to operate for around 90 days, but managed to keep going for a total of 321 days, travelling 10,540 m (6.54 miles) in the process.

Lunokhod 1 (Lunokhod means "moon walker" in Russian) was 2.2 m (7 ft 2 in) long, 2.2 m (7 ft 2 in) wide and had a mass of 756 kg (1,666 lb). Its bathtub-like instrument compartment had a hinged "lid" which opened to reveal its solar panels during the day and closed to insulate the rover's electronics during the night.

The rover was designed to be partially autonomous, largely because of the extremely limited range of commands Soviet mission control could transmit to the rover. It had only five basic movement commands (forward short, forward long, turn 20 degrees left, turn 20 degrees right, and reverse) along with a stop command that would halt whatever it was doing. The rover used its own sensor data to decide how to allocate power and keep track of its movements. It could trigger its own emergency stop if it detected pitch or roll beyond its design parameters.

Contact was lost with Lunokhod in October 1971, but the rover was rediscovered in 2010 by researchers looking through photographs taken by NASA's Lunar Reconnaissance Orbiter. This allowed for scientists on Earth to pinpoint the rover's laser retroreflector and start using the rover for planetary research once again.