Sputnik 7

Sputnik 7 was the first Soviet attempt at a Venus probe. The probe was successfully launched into Earth orbit with a SL-6/A-2-e launcher. The launch payload consisted of an Earth orbiting launch platform (Tyazheliy Sputnik 4) and the Venera probe. The fourth stage (a Zond rocket) was supposed to launch the Venera probe towards a landing on Venus after one Earth orbit but ignition failed, probably due to a faulty timer, and the spacecraft remained in Earth orbit. Because of its large size (6483 kg), the mission was originally thought by non-Soviet observers to be a failed manned mission, and later was described as a test of an Earth orbiting platform from which an interplanetary probe could be launched.