NSSDCA/COSPAR ID: 1966-094A
Luna 12 was a lunar orbiting spacecraft built by the Soviet Union. The objectives of the mission included the study of: (1) lunar gamma- and X-ray emissions in order to determine the Moon's chemical composition; (2) lunar gravitational anomalies; (3) the concentration of meteorite streams near the Moon; and, (4) the intensity of hard corpuscular radiation near the Moon. Another objective was an engineering experiment to test the efficiency of lubricants for gear transmission systems in vacuum for future lunar rovers. The mission operated in lunar orbit for 3 months and returned images and scientific data.
Luna 12 was based on the Ye-6LF spacecraft bus, virtually identical to Luna 11 except for the redesigned propulsion system, designated S5.5A. The redesign was to correct for the defects that caused the Luna 11 failure. It was a cylindrically shaped spacecraft, 2.7 meters high and 1.5 meters in diameter. It had an upper cone holding the instrument module and radiators (which took the place of the lunar lander storage cabin on earlier missions), and a lower truncated cone holding the main engine. Launch mass was 1620 kg and on-orbit mass was roughly 1120 kg.
It had a propulsion system, designated SS.5, that comprised a main engine, propellant tank, attitude control engines, helium tank for pressurization, sensors, and avionics. The attitude control engines were mounted on outriggers near the bottom of the spacecraft. Power was supplied by a battery. A cone-shaped omnidirectional antenna, mounted on the side of the cylinder, was used for communications. An SL-1 radiometer was mounted on top of the instrument module.
The instrument module held most of the scientific payload for the mission: a gamma-ray spectrometer, an RFL-F low-energy X-ray fluorescence spectrometer, a US-3 ultraviolet reflectance spectrometer, an RMCh-1 micrometeorite detector, a long-wave radio astronomy experiment (Kassiopeya KYa-4), and an R-1 gear drive lubricant technology test. Spacecraft tracking was used to map the lunar gravity field. A facsimile film imaging system, consisting of a camera, developing system, and scanner, was mounted on the side of the spacecraft and could return high and low resolution images.
Luna 12 lifted off on a Molniya-M (modified SS_6) and Blok-L booster from Baikonur Cosmodrome on 22 October 1966 at 08:42:26 UT into Earth orbit. It was launched towards the Moon from an Earth-orbiting platform and achieved a 103 x 1742 km, 15 degree inclination lunar orbit on 25 October 1966. The imaging system turned on and operated for 64 minutes, reportedly returning 28 high-resolution and 14 panoramic images on 27 October, although only 2 of the images were ever made public. The spacecraft was then put into a spin-stabilized roll for operation of other experiments. The UV Spectrometer failed to operate. Radio transmissions from Luna 12 ceased on January 19, 1967, after 602 lunar orbits and 302 radio transmissions. The orbits reached a periapse of only 20 km altitude before being raised to 70 km towards the end of the mission. It is assumed the orbit decayed fairly rapidly and the spacecraft impacted the Moon at an unknown location sometime in 1967.
Spacecraft image for illustrative purposes - not necessarily in the public domain.
Launch Date: 1966-10-22
Launch Vehicle: Modified SS-6 (Sapwood) with 2nd Generation Upper Stage + Escape Stage
Launch Site: Tyuratam (Baikonur Cosmodrome), U.S.S.R
Mass: 1620 kg
Questions and comments about this spacecraft can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
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Mr. Artem Ivankov | General Contact | Lavochkin Association | artem.ivankov@laspace.ru |