1VA n°1 (Venera 1)

Tyazhely Sputnik, also known by its development name as 1VA n°1 and in the West as Sputnik 7, was a Soviet spacecraft, which was intended to be the first spacecraft to explore Venus. Due to a problem with its upper stage it failed to leave low Earth orbit. In order to avoid acknowledging the failure, the Soviet government instead announced that the entire spacecraft, including the upper stage, was a test of a "Heavy Satellite" which would serve as a launch platform for future missions. The sister probe, Venera 1, successfully launched and was injected into a heliocentric orbit toward Venus one week later, although telemetry on the mission failed a week into flight.