Luna 8

Launch data: Designation 01810 / 65099A Launch date 03 Dec 1965 - 10:46:14 UT Launch site B, LC31 Launch vehicle Molniya 8K78 Satellite type  E-6 (#12) Mission Lunar impact on December 6, 1965 Maximum distance from Earth 400.000 km All-burnt velocity 10,95 km/sec

Retro delay. Failed to achieve soft landing, lunar impact 6 Dec 1965 at 21h 51m 30s (UT).
Impact: 9,1°N - 63,3°W (9.6°N - 62°W ?)

Specifications:

Mission details:

• Luna 8 (E-6 series) was an unmanned space mission of the Luna program. Also called Lunik 8, Luna 8 was launched with the probable mission of achieving a soft landing on the Moon. However, the retrofire was late, and the spacecraft impacted the lunar surface in Oceanus Procellarum. The mission did complete the experimental development of the star-orientation system and ground control of radio equipment, flight trajectory, and other instrumentation.
• This, the eleventh Soviet attempt to achieve a lunar soft-landing, nearly succeeded. After placement in earth parking orbit 209 x 169 km at 51.8° with period 88.2 min, probe send on moon-intercept course with apogee of 400000 km. After a successful midcourse correction on 4 December, the spacecraft headed toward the Moon without any apparent problems. Just prior to the planned retro-fire burn, a command was sent to inflate cushioning airbags around the ALS lander probe. Unfortunately, a plastic mounting bracket apparently pierced one of the two bags. The resulting expulsion of air put the spacecraft into a spin of 12 degrees per second. The vehicle momentarily regained attitude, long enough for a 9-second retro-engine firing, but then lost it again. Without a full retro-fire burn to reduce approach velocity sufficient for a survivable landing, Luna 8 plummeted to the lunar surface and crashed at 21:51:30 UT on 6 December just west of the Kepler crater. Impact coordinates were 9°8' north latitude and 63°18' west longitude.