Luna E-8-5 No.402, also known as Luna Ye-8-5 No.402, and sometimes identified by NASA as Luna 1969C,^[1] was a Soviet spacecraft under Luna programme which was lost in a launch failure in 1969. It was a 5,600-kilogram (12,300 lb) Luna E-8-5 spacecraft, the first of at least eleven to be launched.^[2][3] It was intended to perform a soft landing on the Moon, collect a sample of lunar soil, and return it to the Earth. It was, along with Luna 15, one of two unsuccessful missions which had been launched by the Soviet Union in a last-ditch attempt to upstage the Apollo 11 landing under Moon race.^[2]

Luna E-8-5 No.402 was launched at 04:00:07 UTC on 14 June 1969 atop a Proton-K 8K78K carrier rocket with a Blok D upper stage, flying from Site 81/24 at the Baikonur Cosmodrome.^[4] The upper stage failed to ignite, and consequently the spacecraft failed to achieve orbit.^[5] Prior to the release of information about its mission, NASA correctly identified that it had been an attempted sample return mission. However, they believed that a previous attempt had been made, using a spacecraft launched on 30 April, which had also been lost in a launch failure. They designated that attempt was Luna 1969B.^[1] No Luna spacecraft or Proton rocket was launched on that date.^[4]