Venera 2

Venera 2, also known as 3MV-4 No.4 was a Soviet spacecraft intended to explore Venus. A 3MV-4 spacecraft launched as part of the Venera programme, it failed to return data after flying past Venus. The Venera 2 spacecraft was equipped with cameras, as well as a magnetometer, solar and cosmic x-ray detectors, piezoelectric detectors, ion traps, a Geiger counter and receivers to measure cosmic radio emissions. The spacecraft made its closest approach to Venus at 02:52 UTC on 27 February 1966, at a distance of 23,810 kilometres. During the flyby, all of Venera 2's instruments were activated, requiring that radio contact with the spacecraft be suspended. The probe was to have stored data using onboard recorders, and then transmitted it to Earth once contact was restored. Following the flyby the spacecraft failed to reestablish communications with the ground. It was declared lost on 4 March, 1966. An investigation into the failure determined that the spacecraft had overheated due to a radiator malfunction.