Mission Type: Rover
Launch Vehicle: Proton booster plus upper stage and escape stages; 8K82K + Blok D (Proton-K no. 259-01)
Launch Site: Tyuratam (Baikonur Cosmodrome), USSR, NIIP-5 / launch site 81L
Spacecraft Mass: about 5950 kg (launch mass); the rover was 840 kg
Spacecraft Instruments: 1) imaging system (three low-resolution TVs and four high-resolution photometers); 2) x-ray spectrometer; 3) penetrometer; 4) laser reflector; 5) radiation detectors; 6) x-ray telescope; 7) odometer/speedometer; 8) visible/ultraviolet photometer; 9) magnetometer; and 10) photodetector
Spacecraft Dimensions: Rover: 135 cm high, 170 cm long, 160 cm wide
Spacecraft Power: Rover: 135 cm high, 170 cm long, 160 cm wide
References:
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi

National Space Science Data Center, http://nssdc.gsfc.nasa.gov/

Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.

Luna 21 carried the second successful Soviet "8YeL" lunar rover, Lunokhod 2, and was launched less than a month after the last Apollo lunar landing.

After a midcourse correction the day after launch, Luna 21 entered orbit around the Moon on 12 January 1973. Parameters were 100 x 90 kilometers at 60° inclination. On 15 January, the spacecraft deorbited and, after multiple engine firings, landed on the Moon at 22:35 UT the same day, inside the LeMonnier crater at 25°51' north latitude and 30°27' east longitude, between Mare Serenitatis and the Taurus Mountains. Less than 3 hours later, at 01:14 UT on 16 January, the rover disembarked onto the lunar surface.

The 840-kilogram Lunokhod 2 was an improved version of its predecessor and was equipped with a third TV camera, an improved eight-wheel traction system, and additional scientific instrumentation. By the end of its first lunar day, Lunokhod 2 had already traveled further than Lunokhod 1 in its entire operational life.

On 9 May, the rover inadvertently rolled into a crater and dust covered its solar panels, disrupting temperatures in the vehicle. Attempts to save the rover failed, and on 3 June, the Soviet news agency announced that its mission was over.

Before last contact, the rover took 80,000 TV pictures and 86 panoramic photos and had performed hundreds of mechanical and chemical surveys of the soil. The Soviets later revealed that during a conference on planetary exploration in Moscow, 29 January to 2 February 1973 (that is, after the landing of Luna 21), an American scientist had given photos of the lunar surface around the Luna 21 landing site to a Soviet engineer in charge of the Lunokhod 2 mission. These photos, taken prior to the Apollo 17 landing, were later used by the "driver team" to navigate the new rover on its mission on the Moon.