NSSDCA/COSPAR ID: 1970-072A
Luna 16 was the first robotic probe to land on the Moon and return a sample to Earth and represented the first lunar sample return mission by the Soviet Union and the third overall, following the Apollo 11 and 12 missions.
Luna 16 was based on the Ye-8-5 spacecraft body, consisting of two attached stages, an ascent stage mounted on top of a descent stage. The lander stood 3.96 meters tall and had an unfueled landed mass of 1880 kg. With a full load of fuel its launch mass was between 5600 and 5750 kg.
The descent stage was the same as the Ye-8 lower stage for the Lunokhod rovers, a cylindrical body with four protruding landing legs, fuel tanks, a landing radar altimeter, and a dual descent engine complex. The main descent rocket, the KTDU-417, was a throttleable 1920 kg thrust engine used for mid-course corrections, orbit insertion, braking for descent to the surface, and to slow the craft until it reached a cutoff point which was determined by the onboard computer based on altitude and velocity. After cutoff a bank of lower thrust (210 and 350 kg) vernier jets was used for the final landing. The descent stage also acted as a launch pad for the ascent stage. The spacecraft descent stage was equipped with a television camera, radiation and temperature monitors, telecommunications equipment, and a 90 cm extendable arm with a drilling rig for the collection of a lunar soil sample. Communications were via a conical antenna at the end of a boom at 768 and 922 MHz (downlink) and 115 MHz (uplink).
The ascent stage was a smaller cylinder with a spherical top which replaced the Lunokhod rover and housing from the Ye-8 bus. It carried a cylindrical hermetically sealed soil sample container inside a spherical re-entry capsule, mounted on a 1920 kg thrust KRD-61 rocket. Total mass of the ascent stage was 520 kg, of which 245 kg was the nitric acid and UDMH propellant. It was 2 meters tall. The sample return cabin was 50 cm in diameter and had a mass of 39 kg. The KRD-61 could only fire once, for 53 seconds, to put it on a free return trajectory to Earth. Specific impulse of the engine was 313 seconds, it could impart a velocity of 2600 - 2700 m/s to the return craft.
The Luna 16 automatic station was launched toward the Moon from a preliminary Earth orbit and after one mid-course correction on 13 September it entered a circular 111 km lunar orbit on 17 September 1970. The lunar gravity was studied from this orbit, and then the spacecraft was fired into an elliptical orbit with a perilune of 15.1 km. The main braking engine was fired on 20 September, initiating the descent to the lunar surface. The main descent engine cut off at an altitude of 20 m and the landing jets cut off at 2 m height at a velocity less than 2.4 m/s, followed by vertical free-fall. At 05:18 UT, the spacecraft soft landed on the lunar surface in Mare Foecunditatis (the Sea of Fertility) as planned, at 0.5137 S, 56.3638 E, approximately 100 km west of Webb crater. This was the first landing made in the dark on the Moon, as the Sun had set about 60 hours earlier. According to the Bochum Radio Space Observatory in the Federal Republic of Germany, strong and good quality television pictures were returned by the spacecraft. However, such pictures were not made available to the U.S. by any sources so there is question as to the reliability of the Bochum report.
The drill was deployed and penetrated to a depth of 35 cm before encountering hard rock or large fragments of rock. The column of regolith in the drill tube was then transferred to the soil sample container. After 26 hours and 25 minutes on the lunar surface, the ascent stage, with the hermetically sealed soil sample container, lifted off from the Moon carrying 101 grams of collected material at 07:43 UT on 21 September. The lower stage of Luna 16 remained on the lunar surface and continued transmission of lunar temperature and radiation data. The Luna 16 re-entry capsule returned directly to Earth without any mid-course corrections, made a ballistic entry into the Earth's atmosphere on 24 September and deployed parachutes. The capsule landed approximately 80 km SE of the city of Dzhezkazgan in Kazakhstan at 03:26 UT.
Rendered spacecraft image above credit NASA/NSSDCA (public domain)
Launch Date: 1970-09-12
Launch Vehicle: Proton Booster Plus Upper Stage and Escape Stages
Launch Site: Tyuratam (Baikonur Cosmodrome), U.S.S.R
Mass: 5600 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 |