Luna - Exploring the Moon
2017 Jan 25
Wednesday, Day 25
Selected Luna Missions:
A different view from Ian Ridpath
Summarised by Don P Mitchell
The Mission of Luna 13
Luna 13 was the Soviet Union's second succesful lunar lander and, like its predecessor Luna 9, sent back photographs of the surface as well as testing the lunar soil.
Luna 13's design is similar to Luna 9 but with additional instruments to take measurements of the Moon's surface. Two booms carrying these sensors can be seen in the illustration, deployed by small explosive charges to bring them into contact with the surface. Its camera system has two lenses with a small horizontal separation to permit stereoscopic imaging.
A soil penetrometer was used by Luna 13 to measure the density of the upper layer of the Moon's soil. It was mounted at the end of one of the long booms deployed by the landing capsule. The body of the tube was 35 centimetres in diameter and the short rod with a pointed tip was driven into the Moon by a small explosive charge contained in the cylinder.
Following a landing softened by inflatable air bags, similar to that of Luna 9, the capsule unfolded its petals and booms and went to work - four minutes later it began to transmit.
When the penetrometer was activated, the rod went 45 centimetres into the Moon and revealed that the surface layer was made up of a soil-like medium with a density around 1.0 grammes per cubic centimetre. The second boom carried instruments to measure mechanical and physical properties, and the cosmic-ray reflectivity of the Moon's surface.
The granular nature of the soil can be seen in the panoramic photograph below. Also to be seen are shadows of both of Luna 13's pair of panoramic camera imaging devices and its rod-shaped radio aerials.
Luna 13 Statistics:
Launch Vehicle: Molniya
Launching Technique: Low orbit around the Earth and then a direct landing trajectory
Mass: approx 1,600 kilogrammes (fully fuelled and including 150kg lander)
Length: 2.5 metres (including lander)
Maximum Diameter: 1.0 metres
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