The Luna 21 mission embarking the rover Lunokhod 2 was launched on 8 January 1973. Here again, the mission is carried out in a nominal way: the rover travels 37 km and survives for 5 months.
The Luna 21 spacecraft landed on the Moon and deployed the second Soviet lunar rover (Lunokhod 2). The primary objectives of the mission were to collect images of the lunar surface and examine ambient light levels to determine the feasibility of astronomical observations from the Moon.
Lunokhod 2 was equipped with three TV cameras, one mounted high on the rover for navigation, which could return high resolution images at different rates (3.2, 5.7, 10.9 or 21.1 seconds per frame). These images were used by a five-man team of controllers on Earth who sent driving commands to the rover in real time. After landing, the Lunokhod 2 took TV images of the surrounding area, then rolled down a ramp to the surface at 01:14 UT on 16 January and took pictures of the Luna 21 lander and landing site. It stopped and charged batteries until 18 January, took more images of the lander and landing site, and then set out over the Moon. The rover would run during the lunar day, stopping occasionally to recharge its batteries via the solar panels. At night the rover would hibernate until the next sunrise, heated by the radioactive source. Lunokhod 2 operated for about 4 months, covered 37 km of terrain including hilly upland areas and rilles, and sent back 86 panoramic images and over 80,000 TV pictures.