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Luna - Exploring the Moon


Scarborough, UK
2014 Oct 23
Thursday, Day 296

Maintained by:





Selected Luna Missions:















Elsewhere:

A different view from Ian Ridpath

Summarised by Don P Mitchell


The Mission of Luna 21

Luna 21 acted as transport to get the Lunokhod 2 roving vehicle onto the lunar surface. The Luna 21 descent stage was similar to all of its predecessors in this phase of Soviet lunar exploration.

Lunokhod 2

Lunokhod 2The main differences between Lunokhod 2 and Lunokhod 1 (delivered to the Moon by Luna 17) can be seen in this photograph.

The principal one is an additional high-level TV camera. It was used to create panoramic views and also gave Lunokhod's drivers the opportunity to get a batter view of the lunar topography. All lenses have improved sunshades.

The small silver box between the front wheels is an alpha particle emitter which can be lowered onto the Moon to measure soil composition. The instrument was also carried by Lunokhod

Like its predecessor, Lunokhod 2 carried a French-built retro-reflector for use with a laser beam transmitted from Earth. It allowed the Earth-Moon distance to be measured to an accuracy around 20 centimetres.

Luna 21 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
1973 Jan 8 06:55 Luna 21 (E-8-204) launched from the Baikonur cosmodrome by four-stage Proton rocket into 190 x 235 kilometre orbit around the Earth at 51.6 degrees inclination - its mission is to enter orbit around the Moon and then land the Lunokhod 2 remote-controlled roving vehicle on its surface
1973 Jan 8 08:05 Final stage of Luna 21 launching rocket fired to place it into a trajectory towards the Moon
1973 Jan 9 Luna 21 rocket engine is used to correct its trajectory towards the Moon
1973 Jan 12 14:25 Approx time - Luna 21 enters 90 x 110 kilometre circular orbit around the Moon at 60 degrees inclination
1973 Jan 13 Luna 21 rocket engine is used to lower the perilune (lowest height above the Moon) of its orbit
1973 Jan 14 After firing its onboard rocket engine, Luna 21 orbit around the Moon is now 16 x 110 kilometres at 60 degrees inclination
1973 Jan 15 22:29 Luna 21 fires its rocket engine and begins its descent towards a landing on the Moon surface
1973 Jan 15 22:35 After completing 40 orbits of the Moon, Luna 21 lands at 28.85 degrees north, 30.45 degrees in the Le Monnier crater at the eastern edge of the Mare Serenitatis
1973 Jan 16 01:14 Lunokhod 2 descends a pair of ramps on Luna 21 landing stage and moves onto the moon surface - it travels 30 metres from Luna 21 and is parked
1973 Jan 18 Lunokhod 2 is moved to a position where it can take TV pictures of Luna 21 and the area around it before setting out on its travels
1973 Jan 24 Lunokhod 2 is parked for its first lunar night, having travelled 1,260 metres and carried out a programme of photography and soil measurements - it protective 'lid' is closed
1973 Feb 8 Lunokhod 2 'lid' is opened and its batteries begin to charge prior to it second lunar day on the Moon
1973 Feb 23 Lunokhod 2 is parked for its second lunar night, having travelled 9,086 metres and continued its programme of photography and soil measurements - it protective 'lid' is closed
1973 Mar 11 Lunokhod 2 'lid' is opened and its batteries begin to charge prior to it third lunar day on the Moon
1973 Mar 23 Lunokhod 2 is parked for its third lunar night, having travelled 16,533 metres and continued its programme of photography and soil measurements - it protective 'lid' is closed
1973 Apr 9 Lunokhod 2 'lid' is opened and its batteries begin to charge prior to it fourth lunar day on the Moon
1973 Apr 22 Lunokhod 2 is parked for its fourth lunar night, having travelled 8,600 metres and continued its programme of photography and soil measurements - it protective 'lid' is closed
1973 May 8 Lunokhod 2 'lid' is opened and its batteries begin to charge prior to it fifth lunar day on the Moon
1973 Jun 3 Lunokhod 2 is officially declared 'dead', having travelled a further 880 metres (it probably ceased to operate at least two weeks earlier, during the lunar day) - it has traveled a total of 37 kilometres and transmitted over 80,000 TV pictures and 86 TV panoramas, as well as conducting over 700 lunar soil tests
Copyright © Robert Christy, all rights reserved
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