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Luna 9



Luna 9 was the first spacecraft to achieve a lunar soft landing and to transmit photographic data from the Moon's surface to Earth, preceding the U.S. Surveyor 1 soft lander by about 4 months. The probe also proved that the lunar surface could support the weight of a lander and that an object would not sink into a loose layer of dust as some models predicted. Luna 9 launched on 31 January 1966 at 11:41 UT (14:41 Moscow time) from Baikonur Cosmodrome and reached the Moon on 3 February.

Spacecraft and Subsystems

The spacecraft comprised two parts, which had a total mass of 1538 kg and stood 2.7 meters tall. The Luna 9 automatic lunar station that achieved the soft landing was a spherical body with a diameter of 58 centimeters and a mass of 99 kg. The station consisted of a hermetically sealed container, pressurized to 1.2 atmospheres, which held the radio system, programming device, batteries, thermal control system and scientific apparatus. Four antennas that automatically opened after landing were mounted on the outside of the compartment. An airbag amortization system to cushion the landing was also mounted outside the station. The entire compartment was mounted above a flight stage which held the main KTDU-5A retrorocket, four outrigger vernier rockets, a toroidal aluminum alloy fuel tank, a 90 cm diameter spherical oxidizer tank, fuel pumping system, the nitrogen tank for airbag inflation, and guidance and landing sensor equipment. This equipment included gyroscopes, electro-optical apparatus, the soft-landing radar system, and small orientation engines. Compartments on either side of the main body with a total mass of 300 kg contained guidance radar and the 3 nitrogen jets and gas bottles of the attitude control system for the cruise stage, designed to be jettisoned once the descent was underway. The total propellant load (amine-based fuel and nitric acid oxidizer) was about 800 kg. The scientific equipment comprised a lightweight (1.5 kg) panoramic television camera and an SBM-10 radiation detector. A mirror on an 8 cm turret was mounted on the top of the lander above the camera to allow 360 degree coverage. The scientific container was designed to separate from the flight stage immediately before touchdown. The thermal control system maintained the interior temperature between 19 and 30 degrees C. All operations were battery powered.

Mission Profile

The Luna 9 payload was carried to Earth orbit by an A-2-E vehicle and then conveyed toward the Moon by a fourth stage rocket that separated itself from the payload on January 31. The spacecraft spun up to 0.67 rpm by the nitrogen jets. A mid-course correction, involving a 48 second burn, took place on 1 February at 19:29 UT (22:29 Moscow time), resulting in a delta-V of 71.2 m/sec. At an altitude of 8300 km the spacecraft was oriented for retro-rocket firing and its spin was stopped. At 75 km altitude, 48 seconds before landing at a velocity of 2.6 km/s, the radar altimeter sent commands to jettison the side modules, inflate the airbags, and begin retrorocket firing. At 250 meters from the surface the main retrorocket was turned off and the four outrigger engines were used to slow the craft. At a height of about 5 meters a contact sensor touched the ground, the engines were shut down, and the landing capsule was ejected, impacting the surface at 22 km/hr, bouncing several times and coming to rest in Oceanus Procellarum (Ocean of Storms) west of Reiner and Marius craters at approximately 7.08 N, 64.37 W on February 3, 1966 at 18:45:30 UT (21:45:30 Moscow time). After about 250 seconds the four petals, forming the top shell of the spacecraft, opened outward and stabilized the spacecraft on the lunar surface. Spring-controlled antennas assumed operating positions, and the television camera rotatable mirror system, which operated by revolving and tilting, began a photographic survey of the lunar environment 250 seconds after landing. The first test image, which showed very poor contrast because the Sun was only about 3 degrees above the horizon, was completed 15 minutes later. Seven radio sessions, totaling 8 hours and 5 minutes, were transmitted as were three series of TV pictures. When assembled, the photographs provided four panoramic views of the nearby lunar surface. The pictures included views of nearby rocks and of the horizon 1.4 km away from the spacecraft. They showed Luna 9 had landed near the rim of a 25 meter diameter crater at a tilt of about 15 degrees. The probe took the first full panorama on 4 February from 1:50 to 3:30 UT, with the Sun 7 degrees above the horizon. After the first panorama was taken the probe slipped as the regolith on the slope settled, and was at a 22.5 degree tilt when the second panorama was taken at 15:30 to 17:10 UT on 4 February. Two more panoramas were obtained, on 5 February from 16:00 to 17:40 UT, and the next day from about 20:00 to 21:00 UT. The pictures included views of nearby rocks and of the horizon 1.4 km away from the spacecraft. Radiation data were also returned, showing a dosage of about 30 millirads per day. On 6 February at 22:55 UT the batteries ran out of power and the mission ended.

Spacecraft image for illustrative purposes - not necessarily in the public domain.

Alternate Names

  • Lunik 9
  • 01954

Facts in Brief

Launch Date: 1966-01-31
Launch Vehicle: Modified SS-6 (Sapwood) with 2nd Generation Upper Stage + Escape Stage
Launch Site: Tyuratam (Baikonur Cosmodrome), U.S.S.R
Mass: 99.0 kg

Funding Agency

  • Unknown (U.S.S.R)


  • Planetary Science
  • Space Physics

Additional Information

Questions or comments about this spacecraft can be directed to: Dr. David R. Williams.



NameRoleOriginal AffiliationE-mail
Mr. Artem IvankovGeneral ContactLavochkin

Selected References

Davies, J. G., et al., Observations of the Russian moon probe Lunar 9, Nature, 209, 848-850, Feb. 1966.

Kuiper, G. P., et al., Russian Luna 9 pictures, provisional analysis, Science, 12, 1561-1563, Mar. 1966.

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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