USSR - Luna 24

Luna 24 was the last of the Soviet Union's major lunar exploration missions. Its goal was similar to Luna 16 and other predecessors in that it was designed to obtain a core sample from the surface. The difference between Luna 24 and those that had gone before was that its sample was to be 2.5 metres below the surface with the corresponding engineering challenge of fitting a long core of soil and rock into the small sample-return vehicle.

This drawing is one of many with a space exploration theme created by Soviet cosmonaut Alexei Leonov. It depicts Luna 24 on the Moon's surface. The twin rails of the drill mechanism can be seen at the right front of the lander.

The system worked by having the drill motor travelling on this pair of rails while the long drill bit (seen between the lower sections of rail) penetrated the Moon. As the core sample was retracted, another mechanism ensured that it slid away into a flexible tube. The tube was then was coiled tightly before being transferred to the return capsule.

The wedge-shaped protective shield next to the capsule keeps the drill head and the spiral packing device away from direct solar heating while in the rest position. Too much thermal expansion or contraction could have resulted in Luna 24 being unable to pack away the sample. In the event it succeeded.

On the left is the tightly-coiled soil sample, still in the protective tubing into which it was inserted while on the Moon. It was wound like a spiral spring in order to create a cylinder that could be loaded into the return capsule. the return capsule itself was similar to that of Luna 16 with the same rocket engine and fuel tank layout to get the capsule back to Earth.

Luna 24 Statistics:

Launch Vehicle: Proton (four stage version)
Launching Technique: Low orbit around Earth, translunar trajectory, then lunar orbit followed by landing
Mass: 1,900 kilogrammes (approx) on lunar surface
Length: 2.3 metres)
Maximum Diameter: 3.3 metres (including landing legs)

Date	Time (UTC)	Event
1976 Aug 9	15:04	Luna 24 (E-8-5M-412) launched from the Baikonur cosmodrome by four-stage Proton rocket into 183 x 246 kilometre orbit around the Earth at 51.5 degrees inclination - its mission is to enter orbit around the Moon, then land and return a soil sample to Earth
1976 Aug 9	16:14	Final stage of Luna 24 launching rocket fired to place it into a trajectory towards the Moon
1976 Aug 11		Luna 24 rocket engine is used to correct its trajectory towards the Moon
1976 Aug 13	23:11	Luna 24 fires its rocket engine and enters a 115 kilometre circular orbit around the Moon at 120 degrees inclination
1976 Aug 16		Luna 24 rocket engine is used to adjust its orbit around the Moon
1976 Aug 17		After firing its onboard rocket engine, Luna 24 orbit around the Moon is now 12 x 120 kilometres at 120 degrees inclination
1976 Aug 18	06:30	Luna 24 fires its rocket engine and begins its descent towards a landing on the Moon surface
1976 Aug 18	06:36	Luna 24 lands on the Moon at 12.75 degrees north, 62.20 degrees east in the Mare Crisium, a few hundred metres from Luna 23
1976 Aug 18		Luna 24 uses a long, hollow drill to collect a 1.6 metre core sample of the lunar surface - it weighs 170 grammes - it is coiled as it is deposited inside the return craft
1976 Aug 19	05:25	Luna 24 return stage fires its rocket motor and begins its journey back to Earth
1976 Aug 22	17:55	Luna 24 re-entry capsule touches down 200 kilometres south-east of Surgut
1976 Aug 24		The Soviet Union reports that it is still maintaining communication with Luna 24 on the Moon - this is the last formal announcement in the Soviet Luna programme