This was the second of three 3MV spacecraft the Soviets attempted to launch towards Venus in late 1965. Venera 3 successfully left Earth orbit carrying a small 3-foot (0.9-meter) diameter 683-pound (310-kilogram) landing capsule to explore the Venusian atmosphere and transmit data on pressure, temperature, and composition of the Venusian atmosphere back to Earth during the descent by parachute.
During the outbound trajectory, ground controllers successfully performed a mid-course correction on Dec. 26, 1965 and completed 63 communications sessions during which scientists on the ground recorded valuable information.
For example, between Nov. 16, 1965 and Jan. 7, 1966, a modulation charged particle trap (of the same type carried on Zond 2), provided valuable data on the energy spectra of solar wind ion streams beyond the Earth’s magnetosphere.
Contact was, however, lost on Feb. 16, 1966, shortly before the Venusian encounter. The spacecraft subsequently automatically released its lander probe which impacted inertly onto the Venusian surface at 06:56:26 UT on March 1, 1966, only 4 minutes earlier than planned. It was the first time a human-made object made physical contact with another planetary body other than the Moon.
The impact location was on the night side of Venus, near the terminator, in the range of minus 20 degrees to 20 degrees north latitude and 60 degrees to 80 degrees east longitude.
In response to concern from some American and British scientists, the Soviet press emphasized that “prior to liftoff, the descent module was subject to careful sterilization, required to dispose of all microorganisms of terrestrial origin and thus prevent the possibility of contamination.”
Later investigation confirmed that Venera 3 suffered many of the same failures as Venera 2, i.e., overheating of internal components and the solar panels.
Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.