Soviet engineers designed the Venera 7 lander to withstand pressures of up to 100 atmospheres and temperatures reaching 475 degrees Celsius. Designers chose a large margin of error due to significant uncertainties about actual conditions on the planet.
Venera 7 lifted off from Earth at 05:38 UTC on the 17th of August 1970. The spacecraft consisted of an interplanetary bus based on the 3MV system attached to the lander module.
The parachute began failing rapidly six minutes after unreefing and eventually failed completely, leaving the probe in freefall toward the ground. The impact happened at 05:37:10 UTC on the 15th of December 1970.
Coordinates placed the crash site near 5 degrees north latitude and 348 degrees east longitude. The lander struck the surface at approximately 16.5 meters per second.
Radio astronomer Oleg Rzhiga reviewed those tapes weeks later and discovered another 23 minutes of very weak signals hidden within the recordings. The spacecraft had likely bounced onto its side, misaligning the medium gain antenna for proper transmission back to Earth.