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Luna 6

NSSDCA/COSPAR ID: 1965-044A

Description

Luna 6 (Ye-6 no.7) was an attempted lunar soft landing mission. It was similar to the Luna 5 design, also carrying an imaging system and a radiation detector. It launched on 8 June 1965 at 7:41 UT. During the mid-course correction on 9 June the main retro-rocket failed to cut off as scheduled and fired until all of its propellant was exhausted, due to an erroneous ground command sent to the timer. This put the spacecraft on a trajectory to miss the Moon. The spacecraft was put through all the motions of an actual landing, jettisoning the lander and deploying the airbags, as an apparently successful practice run for the ground crew despite the fact that it flew by the Moon at a distance of 161,000 km on 11 June. Contact was lost at a distance of 600,000 km from Earth, the spacecraft presumably entering a heliocentric orbit.

Spacecraft and Subsystems

The spacecraft was built by design bureau OKB-1 based on the Soviet Ye-6 design, which consisted of a stack of three cylindrical modules. The first module was the Isayev rocket module, which held the main engine, used for midcourse correction and the descent to landing, four thrusters for attitude control, and two cruise modules. The main engine propellant was hypergolic nitric acid and amine, and could produce a thrust of about 45,000 N. The four thrusters were mounted on outriggers and could produce 245 N each. A 5-meter boom would be deployed from the bottom of the spacecraft, used to trigger the final landing sequence. The second module was a hermetically sealed pressurized compartment that contained communication, attitude orientation, an altimeter, and the I-100 control system. It also held the propellant and oxygen.

The third module was the lunar lander, a 58 cm diameter sphere protected by two hemispherical airbags. The 105 kg sphere had a hermetically sealed compartment that held communications apparatus, batteries, thermal control systems, a timer, and the science experiments. The top of the sphere had four petals, which would open up on landing, allowing deployment of four 75 cm whip antennas and the lander camera turret. Control of the lander was done by the timing device onboard or by communication from Earth. The batteries were designed to operate for a total of 5 hours over about 4 days. The scientific payload contained an imaging system and an SBM-10 radiation detector. The three sections had a height of 2.7 meters and a launch mass of 1442 kg.

The mission plan was to initialize the landing sequence at an altitude of about 8300 km. At 70 - 75 km altitude the cruise modules would be jettisoned, the main engine would start, the radar altimeter would be activated, and the lander airbags would inflate. At 250 to 265 meters altitude the main engine would shut off and the four thrusters would ignite. The 5 meter boom would touch the surface first, causing the ejection of the lander, which would hit the surface, cushioned by the airbags, at about 15 m/s. The airbags would deflate, the petals would open, causing the sphere to be oriented correctly, and the antennas and instruments could be deployed.

Alternate Names

  • Lunik 6
  • 01393
  • Luna6
  • Ye-6 no.7

Facts in Brief

Launch Date: 1965-06-08
Launch Vehicle: Modified SS-6 (Sapwood) with 2nd Generation Upper Stage + Escape Stage
Launch Site: Tyuratam (Baikonur Cosmodrome), U.S.S.R
Mass: 1442 kg

Funding Agency

  • Unknown (U.S.S.R)

Disciplines

  • Planetary Science
  • Space Physics

Additional Information

Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office

 

Selected References

  • Lunik 5 and 6, TRW Space Log, TRW Systems, 5, No. 2, 55, Redondo Beach, Calif., 1965.
  • Shelton, W., Soviet space exploration - the first decade, Arthur Barker Ltd., Unnumbered, London, England, 1969.
  • Johnson, N. L., Handbook of soviet lunar and planetary exploration - volume 47 science and technology series, Amer. Astronau. Soc. Publ., 1979.
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