The Proton / Block D launcher put the spacecraft into Earth parking orbit followed by translunar injection. On 12 January 1973, Luna 21 braked into a 90 x 100 km orbit about the Moon. On 13 and 14 January, the perilune was lowered to 16 km altitude. On 15 January after 40 orbits, the braking rocket was fired at 16 km altitude, and the craft went into free fall. At an altitude of 750 meters the main thrusters began firing, slowing the fall until a height of 22 meters was reached. At this point the main thrusters shut down and the secondary thrusters ignited, slowing the fall until the lander was 1.5 meters above the surface, where the engine was cut off. Landing occurred at 23:35 GMT in LeMonnier crater at 25.85 degrees N, 30.45 degrees E. The lander carried a bas relief of Lenin and the Soviet coat-of-arms. After landing, Lunokhod 2 took TV images of the surrounding area, then rolled down a ramp to the surface at 01:14 GMT 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. Many mechanical tests of the surface, laser ranging measurements, and other experiments were completed during this time. On June 4 it was announced that the program was completed, leading to speculation that the vehicle probably failed in mid-May or could not be revived after the lunar night of May-June. The Lunokhod was not left in a position such that the laser retroreflector could be used, indicating that the failure may have happened suddenly. References: 1 , 2 , 5 , 6 , 67 , 274 , 296 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

MSFC began implementation of a plan for preparation and storage of unassigned Saturn hardware, phaseout of the Saturn V production capability, and amendment of the facility operations contract at the Michoud Assembly Facility for minimum surveillance of stored hardware.

Replaced Cosmos 460. Possible ELINT satellite. References: 1 , 2 , 5 , 6 .

Investigation of the upper atmosphere and outer space. References: 1 , 2 , 5 , 6 , 99 .

Ames Research Center requested that six R4D rocket engines designed for use in the Apollo program be transferred from MSC to Ames. Possibly the engines would be suitable for the retro-injection function in the Pioneer Venus series of atmospheric probe and orbiter missions. First launch was planned for early 1977. References: 16 .

Investigation of the upper atmosphere and outer space. References: 1 , 2 , 5 , 6 .

MSFC Director Eberhard F. M. Rees retired. He had served as Director since 1 March 1970. Rocco A. Petrone, NASA Apollo Program Director, became the new MSFC Director.

Final crews selected for a dual Soyuz mission in Earth orbit to test the Kontakt docking system to be used on the lunar landing LOK and LK spacecraft. The Kontakt-A Soyuz would have been the active spacecraft, simulating the LOK lunar orbiter.

Final crews selected for a dual Soyuz mission in Earth orbit to test the Kontakt docking system to be used on the lunar landing LOK and LK spacecraft. The Kontakt-P Soyuz would have been the passive spacecraft, simulating the LK lunar lander.

Area survey photo reconnaissance satellite; returned film capsule. References: 1 , 2 , 6 .

Uncertain if Molniya-1T model was Molniya-1 or Molniya-1T. Operation of a system of long range telephone-telegraph radiocommunication, and transmission of USSR Central Television programmes to the stations of the Orbita network. References: 1 , 2 , 5 , 6 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

Solar flare monitor. Study of the processes of solar activity and of their influence on interplanetary space and the Earth's magnetosphere. References: 1 , 2 , 5 , 6 .

The Manned Spacecraft Center was renamed the Lyndon B. Johnson Space Center by Public Law 93-8. The late President's interest and support of the space program began while he was Chairman of the Senate Committee on Aeronautical and Space Sciences and continued during his tenure as Vice President and President. References: 16 .

Possible ELINT satellite. References: 1 , 2 , 5 , 6 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

The improved model had an increased frequency range and on-board method of determining the position of fixed transmitters. The Tselina-2 prime contractors were TsNIRTI Minradioprom (M E Zaslovskiy) for the ELINT equipment and KB Yuzhnoye (KB-3, B S Khimrov) for the spacecraft bus. The launch vehicle was by OKB MEI Minvuza (A F Bogomolov) and the encrypted communications system by 0-TsNII KS MO.

The Apollo Spacecraft Program Office, with Glynn S. Lunney as Manager, was reorganized. Lunney was also Manager for ASTP (Apollo/Soyuz Test Project), an assignment to which he had been appointed in June of 1972. References: 16 .

High resolution photo reconnaissance satellite; returned film capsule; maneuverable. References: 1 , 2 , 6 .

Second launch of Rhyolite geostationary ELINT satellite. References: 1 , 2 , 5 , 6 , 172 , 278 .

KH-9 type satellite. Space craft engaged in investigation of spaceflight techniques and technology (US Cat A). References: 1 , 2 , 5 , 6 .

A Lunar Programs Office, under which the Lunar Data Analysis and Synthesis Program would be conducted, was established in the Office of Space Science, NASA Hq. The office was responsible for continued operation and collection of data from the Apollo lunar surface experiment packages and the Apollo 15 subsatellite; Apollo surface and orbital science data analysis by principal investigators; development of selenodetic, cartographic, and photographic products; continued lunar laser ranging experiment; continued lunar sample analysis; lunar supporting research and technology; and advanced program studies. References: 16 .

Consideration was being given to the feasibility of a second set of Skylab missions (designated Skylab-B) during the interval between the Apollo-Soyuz Test Project in 1975 and the start of Space Shuttle operations late in 1979. The inherent worth of a Skylab-B was recognized, but officials were reluctant to recommend it, on the premise that it would be unwise to allow it to delay or displace the development of the Space Shuttle and other programs already included in the FY 1974 budget.

Acquisition of meteorological information needed for use by the weather service. References: 1 , 2 , 5 , 6 .

Area survey photo reconnaissance satellite; returned film capsule; separated Nauka autonomous subsatellite 16KS No 162 / 2L which tested Kondor control system for Yantar satellite. References: 1 , 2 , 6 , 69 .