USSR - Luna 10

Luna 10 was the first spacecraft to reach the vicinity of the Moon and then go into orbit around it. The basic design was similar to Luna 9's but the landing vehicle was replaced by a small satellite and the main engine was used to reduce speed in order to enter orbit rather than as a soft-landing retro rocket.

The complete Luna 10 spacecraft poses here prior to being mated to its carrier rocket and being despatched to the Moon. Its E-6 flight bus is similar to Luna 9's but the two-part, tapered cylindrical section with the short antennae, situated at the top, is the actual Moon satellite.

Minutes after Luna 10 went into orbit around the Moon, the lunar satellite separated, went into its own orbit close to that of the parent craft, and began to operate in its own right.

The lunar satellite was unstabilised but its instruments were able to measure the electrical, magnetic and radiation fields in near-lunar space. As it was battery powered, the satellite had a limited lifetime. Radio transmissions ceased after 57 days.

Luna 10 is no longer in orbit - the lunar gravitational pull over the Mare areas is greater than over the mountains. The rocks which cause this are referred to as 'Mascons' (short for 'Mass Concentrations'). The result is that satellite trajectories are constantly changing and at some point there is the likelihood of a collision with the Moon. Luna 10 has certainly suffered that fate by now.

Luna 10 Statistics:

Launch Vehicle: Molniya
Launching Technique: Low orbit around the Earth and then a direct landing trajectory
Mass: 1,600 kilogrammes fully fuelled (including 245 kg orbiter)
Length: 2.7 metres (including orbiter)
Maximum Diameter: 1.0 metres

Date	Time (UTC)	Event
1966 Mar 31	10:46	Luna 10 (E-6S-206) launched from the Baikonur Cosmodrome by Molniya rocket into approx 190 x 220 kilometre orbit around the Earth at 51.8 degrees inclination - its mission is to enter orbit around the Moon
1966 Mar 31	11:53	Final stage of Luna 10 launching rocket fired to place it into a trajectory towards the Moon
1966 Apr 1		Luna 10 rocket engine is used to correct its trajectory towards the Moon
1966 Apr 3	18:44	Luna 10 fires its retro-rocket for 57s with engine shutdown at 18:45:39 UTC, resulting in a 350 x 1,017 kilometre orbit around the Moon at 67° 9' 37" inclination
1966 Apr 3	19:00	Luna 10 Immediately on completion of the engine firing, an instrumented payload compartment separates from the flight vehicle and begins its mission to study gamma-radiation, electric and magnetic fields, micro-meteoroids, the solar wind, infrared emissions from the Moon itself, and radiation conditions in the lunar environment
1966 Apr 3		Luna 10 transmits a sythesised rendering of the song 'Internationale' - it is relayed to the Congress of the Communist party of the Soviet Union where it is played to the delegates
1966 May 30		Luna 10 radio transmitters are switched off when battery power becomes too low after 460 orbits around the Moon, and 219 active data transmissions - its orbit is 378 x 985 kilometres at 72.0 degrees inclination