|Launch Date||Jan. 29, 1969|
|Launch Site||Baikonur Cosmodrome, Kazakhstan, Russia | Launch Site 81L|
This was the Soviets' sixth attempt to send an unmanned spacecraft around the Moon and back to Earth.
None. Malfunctions of the second- and third-stage engines prevented the spacecraft from launching properly.
This was the sixth attempt at a robotic circumlunar flight in support of the L1 piloted lunar program and the first after the resounding success of the American Apollo 8 in December 1968.
The Proton launch vehicle lifted off on time, and first-stage operation was nominal. However, during second-stage firing, one of the four engines of the stage mysteriously switched off at T+313.66 seconds. The other engines continued firing, but subsequently, the primary third-stage engine also switched off during its firing sequence at T+500.03 seconds due to a breakdown in the main pipeline feeding fuel to the fuel gas generator.
After a near-ballistic flight, the L1 payload landed near the border between the USSR and Mongolia.
Launch Vehicle: 8K82K + Blok D (Proton-K no. 237-01)
Spacecraft Mass: 5,375 kilograms
Siddiqi, Asif A. Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, NASA, 2002.