Luna Programme

Design lineage: the E series and Lavochkin

The craft flown under the Luna name were a family of distinct designs, not one vehicle. The designations came from the E-series letters assigned in the late 1950s to payloads of the R-7 intercontinental ballistic missile under development. E1 was lunar impact, E2 and E3 were flybys and far-side photography, E6 was soft landing, E6S, E6LF and E6LS covered orbiters and communications craft, E8 was a landing platform carrying a rover, and E8-5 and E8-5M were sample returners. Some designs proposed within the series were never realised, including the E4 concept of a nuclear explosion on the lunar surface.

The E-series was developed at the OKB-1 design bureau in Podlipki from the late 1950s until 1965. Starting with the E6 family, the projects were transferred to the design bureau of the Lavochkin aviation plant in Khimki, since OKB-1 was occupied with the human lunar expedition. Luna 9 was the first successful deep-space probe built by Lavochkin, which would go on to design and build almost all Soviet, later Russian, lunar and planetary spacecraft.

Concealed failures and the confrontation of 1969

Throughout the programme the Soviet practice was to release no details of launches that failed to reach orbit. Twenty-four spacecraft formally received the Luna designation even though more were launched; those that failed in low Earth orbit were usually given Cosmos designations, and Western observers had to assign their own names. Of the launches from Baikonur between 1958 and 1976, seventeen of thirty-three failed.

Luna 15 was in lunar orbit at the same time as Apollo 11. It began its descent on 21 July 1969, while the American astronauts were completing the first moonwalk, and crashed into a mountain minutes later, hours before the scheduled American liftoff from the surface. The Soviet Union released the probe's flight plan so that it would not collide with Apollo 11, but never publicised the exact purpose of the mission. An earlier E8-5 launched in June 1969 failed to reach Earth orbit when the third stage did not ignite, and the attempts of September and October that year were announced as Cosmos 300 and Cosmos 305.

Samples, rovers and the shutdown

Luna 16 in September 1970, Luna 20 in February 1972 and Luna 24 in August 1976 returned lunar soil to Earth, a total of 324 grams across the three missions. Luna 24 sampled material from depths of up to 2.5 metres, and the age of the regolith it brought back was determined to be around 300 million years. The rovers carried by Luna 17 in November 1970 and Luna 21 in January 1973 were the first robotic wheeled vehicles to explore another world. Lunokhod 1 travelled 10.5 kilometres over 322 days, returning more than 20,000 television images and 206 high-resolution panoramas, while Lunokhod 2 covered 42 kilometres over about four months.

Launched on 9 August 1976, Luna 24 proved to be the last Soviet mission to the Moon and the last spacecraft to make a soft lunar landing in the 20th century. Six months before its launch the Soviet government had cancelled the effort to land cosmonauts on the Moon, and in 1977 the programme was formally wound up when the thirty-fourth launch, carrying Lunokhod 3, was cancelled. Lunokhod 3 was built but never flew for lack of launchers and funding. Russia revived the name with Luna 25 in 2023, but that probe failed in lunar orbit and is presumed to have crashed.