Luna E-6 No.8 (Ye-6 series), sometimes identified by NASA as Luna 1965A, was a Soviet spacecraft which was lost in a launch failure in 1965. It was a 1,422-kilogram (3,135 lb) Luna Ye-6 spacecraft, the seventh of twelve to be launched, It was intended to be the first spacecraft to perform a soft landing on the Moon, a goal which would eventually be accomplished by the final Ye-6 spacecraft, Luna 9. Luna E-6 No.8 was launched on 10 April 1965, atop a Molniya-L 8K78L carrier rocket, flying from Site 1/5 at the Baikonur Cosmodrome. During third stage flight, a nitrogen pipeline in the oxidiser tank depressurised, which caused a loss of oxidiser flow to the engine and resulted in the engine cutting off.

Wikipedia: https://en.wikipedia.org/wiki/Luna_1965A. Original timeline Wikipedia link: https://en.wikipedia.org/wiki/Luna_program. Related NASA reference: https://nssdc.gsfc.nasa.gov/planetary/tent_launch.html#luna1965a. Description adapted from Wikipedia contributors (CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/).