Mission Type: Atmospheric Probe
Launch Vehicle: Modified SS-6 (Sapwood) with 2nd-generation upper stage + escape stage, 8K78M
Launch Site: Tyuratam (Baikonur Cosmodrome), USSR, NIIP-5 / launch site 1
Spacecraft Mass: 405 kg (probe); 1130 kg (bus and probe)
Spacecraft Instruments:
Probe: 1) radio altimeter; 2) aneroid barometer; 3) eleven gas analyzer cartridges; 4) two resistance thermometers; 5) ionization densitometer; and 6) photoelectric sensors
Bus: 1) magnetometer; 2) cosmic-ray counters; 3) charged-particle traps; 4) ultraviolet photometer
Spacecraft Dimensions: Main bus was about 3.5 m high and 4 m across the deployed solar panels. Probe was a sphere, 1 m in diameter.
Spacecraft Power: Solar panels (main bus) and battery lasting 100 min. (probe)
Antenna Diameter: 2.3 m (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.

Identical to Venera 5, Venera 6 reached Venus after performing 63 communications sessions with Earth and one midcourse correction on 16 March 1969 at a range of 15.7 million kilometers from Earth. Its 405-kilogram lander separated from the main bus 25,000 kilometers from Venus and entered the Venusian atmosphere at a velocity of 11.17 kilometers per second at 06:05 UT on 17 May 1969.

The Venera 6 capsule transmitted data for 51 minutes before contact was lost. It indicated an altitude of about 10 to 12 kilometers at the end, but its atmospheric pressure reading was similar to that measured by Venera 5 at a much higher altitude, indicating that Venera 6 may have come down over a mountain or high plateau. Landing coordinates were -5° latitude and 23° longitude.

Results from the Venera 5 and 6 missions, published by the Soviets in March 1970, seemed to confirm and sharpen earlier findings from Venera 4. The two new spacecraft found that Venus's atmosphere was composed of roughly 93 to 97 percent carbon dioxide (the remainder was split among nitrogen, oxygen, and inert gases). Data from Venera 6 suggested that the ground pressure was about 60 atmospheres and ground temperature was about 400°C. This compared with Venera 4's readings, which indicated pressure at 75 atmospheres and temperature at 500°C.