The Venera 7 was the first spacecraft landing on another planet to transmit data back to Earth. The Russian spacecraft, part of the Venera series of probes to Venus, was launched on 17 August 1970 from Tyuratam, U.S.S.R, it landed on Venus on 15 December 1970. Venera 1 failed, Venera 2 flew past Venus and Venera 3 sent no data. Venera 4, 5 and 6 were crushed by the pressure of the Venus atmosphere.
The Venera 7 lander remained attached to the interplanetary bus during the initial stages of atmospheric entry to allow the bus to cool the lander to -8 °C for as long as possible. After a while the lander was ejected and the parachute opened at a height of 60 km. At this stage atmospheric testing began with results showing the atmosphere to be 97% carbon dioxide.
|Venera 7 Landing Capsule|
|Venus surface, photo taken by Venera 13 (1982)|
During the descent the parachute appeared to fail, as a result the lander impacted with the surface of Venus at about 16.5 m/s (59.4 km/h). The probe appeared to go silent on impact, however, recording tapes kept rolling. The spacecraft had landed on Venus, probably bounced onto its side on landing, and the medium gain antenna was not pointed correctly for strong signal transmission to Earth. The data returned from the surface was temperature data, which gave a reading of 475°C and the atmospheric pressure at the surface turned out to be around 93 atmospheres, comparable to an ocean depth of 800 meters on Earth.
Venera 7 Probe reaches Venus surface (BBC)