Mission Type: Flyby
Launch Vehicle: Modified SS-6 (Sapwood), 8K78 (no. T103-114)
Launch Site: Tyuratam (Baikonur Cosmodrome), U.S.S.R., NIIP-5 / launch site 1
Spacecraft Mass: 6500 kg
Spacecraft Instruments: 1) imaging system (remainder unknown)
References:
eep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, Monographs in Aerospace History No. 24, by Asif A. Siddiqi
National Space Science Data Center, http://nssdc.gsfc.nasa.gov/

Like its two predecessors (launched on 25 August and 1 September 1962), this Soviet Venus probe never left parking orbit around the Earth. The Blok L upper stage, designed to send the spacecraft toward Venus, fired for only 0.8 seconds before shutting down because of unstable attitude.

Later investigation indicated that the upper stage had been put into a tumble by the violent shutdown of the third stage. The tumble had mixed air bubbles within the propellant tanks, preventing a clean firing of the engine.

Unlike its predecessors, this probe was designed for a Venus flyby rather than atmospheric entry and impact. The spacecraft reentered Earth's atmosphere two days after launch.