Launch Vehicle: Molniya-M; 8K78M
Launch Site: Tyuratam (Baikonur Cosmodrome), USSR; NIIP-5 / launch site 1
Spacecraft Mass: About 1100 kg
Spacecraft Instruments: Probe: 1) radio altimeter; 2) aneroid barometer; 3) eleven gas-analyzer cartridges; 4) two resistance thermometers; and 5) ionization densitometer
Bus: 1) magnetometer; 2) cosmic-ray counters; 3) charged-particle traps; and 4) ultraviolet photometer
Spacecraft Dimensions: Main bus was about 3.5 meters high and 4 meters across the deployed solar panels.
Spacecraft Power: Solar panels (main bus) and battery lasting 100 min. (probe)
Antenna Diameter: 2.3 meters (high-gain antenna)
References:
Deep 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/

Solar System Log by Andrew Wilson, published 1987 by Jane's Publishing Co. Ltd.

This identical twin craft to Venera 4 failed to leave Earth orbit when its Blok L transinterplanetary stage failed to fire, apparently because the engine's turbo pump had not been cooled prior to ignition.

The spacecraft remained stranded in Earth orbit and reentered Earth's atmosphere on 25 June 1967.