Luna E-6 No.6

Luna E-6 No.6, sometimes identified by NASA as Luna 1964A,[1] and sometimes known in the West as Sputnik 27, was a Soviet spacecraft which was lost in a launch failure in 1964. It was a 1,422-kilogram (3,135 lb) Luna E-6 spacecraft,[2] the fourth of twelve to be launched.[3] 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 E-6 spacecraft, Luna 9.

Luna E-6 No.6 was launched at 08:15:35 UTC on 21 March 1964, atop a Molniya-M 8K78M carrier rocket,[3] flying from Site 1/5 at the Baikonur Cosmodrome.[4] A connecting rod in the Blok I stage broke, leading to a propellant valve failing to open completely. The stage developed insufficient thrust to reach orbit and it shut down at T+489 seconds. The upper stages and probe reentered the atmosphere and broke up.[5] Prior to the release of information about its mission, NASA correctly identified that it had been an attempt to land a spacecraft on the Moon.[1]