Goals: This was the second Soviet attempt to bring lunar soil back to Earth. Since the Soviet Union launched Luna 15 three days before the announced launch date of Apollo 11, it appears likely that the Soviets hoped to return lunar samples to Earth just before the American astronauts could do so. The spacecraft was also said to be capable of collecting information about the lunar environment, analyzing the chemical composition of lunar rocks, and taking pictures of the lunar surface.
Accomplishments: Luna 15 reached lunar orbit and conducted numerous communications sessions with Earth, during which it may have transmitted data about the lunar space environment. But its primary goal ended in failure when contact was lost on the same day that U.S. astronauts Neil Armstrong and Buzz Aldrin became the first people to set foot on the Moon. It is thought that Luna 15 probably crashed into a mountain while descending to the lunar surface.
13 Jul 1969: Launch
21 Jul 1969: Lunar Impact
Mission Type: Sample Return
Launch Vehicle: Proton Booster plus upper stage and escape stages, 8K82K + Blok D (Proton no. 242-01)
Launch Site: Tyuratam (Baikonur Cosmodrome), USSR, NIIP-5 / launch site 81P
Spacecraft Mass: 5,700 kg
Spacecraft Instruments: 1) stereo imaging system; 2) remote arm for sample collection and 3) radiation detector
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi
National Space Science Data Center, http://nssdc.gsfc.nasa.gov/
Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.
Luna 15, launched only three days before the historic Apollo 11 mission to the Moon, was the second Soviet attempt to recover and bring lunar soil back to Earth. In a race to reach the Moon and return to Earth, the parallel missions of Luna 15 and Apollo 11 were, in some ways, the culmination of the Moon race that defined the space programs of both the United States and the Soviet Union in the 1960s.
After a midcourse correction the day after launch, Luna 15 entered lunar orbit at 10:00 UT on 17 July 1969. The spacecraft remained in lunar orbit for four days while controllers checked all onboard systems and performed two orbital maneuvers. After astronauts Armstrong and Aldrin had already set foot on the Moon, Luna 15 fired its main retrorocket engine to initiate descent to the surface at 15:47 UT on 21 July 1969.
Unfortunately, transmissions ceased only 4 minutes after deorbit at a calculated altitude of 3 kilometers. The spacecraft had probably crashed into the side of a mountain. Impact coordinates were 17° north latitude and 60° east longitude in Mare Crisium.