Luna E-6LS No.112, sometimes identified by NASA as Luna 1968A, was a Soviet spacecraft which was lost in a launch failure in 1968. It was a 1,700-kilogram (3,700 lb) Luna E-6LS spacecraft, the second of three to be launched. The spacecraft was intended to enter Selenocentric orbit, where it would study the Moon, and demonstrate technology for future crewed Lunar missions. Luna E-6LS No.112 was launched at 10:43:54 on 7 February 1968, atop a Molniya-M 8K78M carrier rocket with a Blok-L upper stage, flying from Site 1/5 at the Baikonur Cosmodrome. During third stage flight, a fuel valve or inlet became stuck, resulting in the gas generator consuming fuel at a higher rate than normal.

Wikipedia: https://en.wikipedia.org/wiki/Luna_1968A. Original timeline Wikipedia link: https://en.wikipedia.org/wiki/Luna_program. Related NASA reference: https://nssdc.gsfc.nasa.gov/planetary/tent_launch.html#luna1968a. Description adapted from Wikipedia contributors (CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/).