The Moon

2.6) Missions of the 1970-s

1971 Luna 18 Spacecraft: Luna Ye-8-5. Mass: 5,600 kg.

Attempted lunar soil return mission; crashed while attempting to soft land at Latitude 3.57 N, Longitude 50.50 E - Mare Fecunditatis. Luna 18 used a new method of navigation in lunar orbit and for landing. The spacecraft's designer, Babakhin, had died at age 56 only the month before. Luna 18 successfully reached earth parking orbit before being put on a translunar trajectory. On September 7, 1971, it entered lunar orbit. The spacecraft completed 85 communications sessions and 54 lunar orbits before it was sent towards the lunar surface by use of braking rockets. It impacted the Moon on September 11, 1971, in a rugged mountainous terrain. Signals ceased at the moment of impact. Parameters are for lunar orbit.

Ye-8 Lunar Lander Ye-8 robot lunar soil return spacecraft. Manufacturer's Designation: Ye-8-LS. Class: Planetary. Type: Lunar. Nation: USSR. Agency: MOM. Manufacturer: Lavochkin. Lunar surface mapping. Lunar Orbit (Selenocentric). Total Mass: 5,820 kg.

1971 Luna 19 (Ye-8-LS)

1971 Luna 19 Program: Luna. Mass: 5,810 kg. Perigee: 140 km. Apogee: 140 km. Inclination: 40.6 deg.

Heavy lunar Orbiter; conducted lunar surface mapping. Luna 19 entered an intermediate earth parking orbit and was then put on a translunar trajectory by the Proton Block D stage. It entered lunar orbit on October 3, 1971. Luna 19 extended the systematic study of lunar gravitational fields and location of mascons (mass concentrations). It also studied the lunar radiation environment, the gamma-active lunar surface, and the solar wind. Photographic coverage via a television system was also obtained. Parameters are for lunar orbit.

1972 Luna 20

Spacecraft: Luna Ye-8-5. Mass: 5,600 kg.

Heavy lunar Orbiter; conducted lunar surface mapping. Luna 19 entered an intermediate earth parking orbit and was then put on a translunar trajectory by the Proton Block D stage. It entered lunar orbit on October 3, 1971. Luna 19 extended the systematic study of lunar gravitational fields and location of mascons (mass concentrations). It also studied the lunar radiation environment, the gamma-active lunar surface, and the solar wind. Photographic coverage via a television system was also obtained. Parameters are for lunar orbit.

Soft landed on Moon; returned soil samples to Earth. Landed on Moon 21 February 1972 at 19:19:00 GMT, Latitude 3.57 N, Longitude 56.50 E - Mare Fecunditatis. Luna 20 was placed in an intermediate earth parking orbit and from this orbit was sent towards the Moon. It entered lunar orbit on February 18, 1972. On 21 February 1972, Luna 20 soft landed on the Moon in a mountainous area known as the Apollonius highlands, 120 km from where Luna 18 had crashed. While on the lunar surface, the panoramic television system was operated. Lunar samples were obtained by means of an extendable drilling apparatus. The ascent stage of Luna 20 was launched from the lunar surface on 22 February 1972 carrying 30 grams of collected lunar samples in a sealed capsule. It landed in the Soviet Union on 25 February 1972. The lunar samples were recovered the following day.

1973 Luna 21

Spacecraft: Luna Ye-8. Mass: 5,567 kg.
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.

1974 Luna 22

Program: Luna. Mass: 5,835 kg. Perigee: 220 km. Apogee: 220 km. Inclination: 19.6 deg.
Heavy lunar orbiter. Scientific investigation of the moon and circumlunar space from the orbit of an artificial satellite of the Moon, which was begun by the Luna 19 automatic station. The spacecraft carried imaging cameras and also had the objectives of studying the Moon's magnetic field, surface gamma ray emissions and composition of lunar surface rocks, and the gravitational field, as well as micrometeoroids and cosmic rays. Luna 22 braked into a circular lunar orbit on 2 June 1974. The spacecraft made many orbit adjustments over its 18 month lifetime in order to optimise the operation of various experiments, lowering the perilune to as low as 25 km. Manoeuvring fuel was exhausted on 2 September and the mission was ended in early November. Parameters are for lunar orbit.

1974 Luna 23

Program: Luna. Mass: 5,300 kg. Perigee: 17 km. Apogee: 105 km.

Failed lunar soil return mission. After successfully entering earth orbit, flying to the moon, entering lunar orbit, and descending toward the surface, the spacecraft was damaged during landing in Mare Crisium (Sea of Crises). The sample collecting apparatus could not operate and no samples were returned. The lander continued transmissions for three days after landing. In 1976, Luna 24 landed several hundred meters away and successfully returned samples. Parameters are for lunar orbit.
1975 Ye-8-5M s/n 412 Program: Luna. Mass: 5,300 kg.

Attempted robotic lunar soil return mission. Block D stage failed.Manufacturer's Designation: Ye-8-5M. Class: Planetary. Type: Lunar. Nation: USSR. Agency: MOM. Manufacturer: Lavochkin. Lunar sample return. Conduct of further scientific investigation of the moon and circumlunar space.

1976 Luna 24

Return Vehicle Program: Luna. Perigee: 0.000 km. Apogee: 400,000 km. Inclination: 51.5 deg.
Program: Luna. Mass: 5,306 kg. Perigee: 115 km. Apogee: 115 km. Inclination: 120.0 deg.
Lunar Sample Return. Landed on Moon 18 Aug 1976 at 02:00:00 GMT, Latitude 12.25 N, Longitude 62.20 E - Mare Crisium (Sea of Crisis). The last of the Luna series of spacecraft, Luna 24 was the third Soviet mission to retrieve lunar ground samples (the first two were returned by Luna 16 and 20). The mission successfully returned 170 grams of lunar samples to the Earth on 22 August 1976.

Although the Luna program experienced many ups and downs and failed to lead to a manned mission to the Moon, it also achieved many firsts. Among them were the first flyby of the Moon, the first impact on the Moon, the first photographs of the far side, the first soft landing, the first lunar satellite, the first analysis of lunar soil, the first sample return, and the first lunar rover deployment. These missions also were successful in performing remote sensing and photography of the Moon, operating two rovers on the lunar surface, and returning three sets of lunar samples.