The Soviet lander that transmitted data from Venus’s surface in December 1970 was Venera 7.
Venera 7 reached Venus on 15 December 1970 and became the first spacecraft to make a successful soft landing on another planet and transmit data from its surface. The lander endured crushing atmospheric pressure and temperatures near 475 °C, conditions that quickly overwhelmed its communications performance.
The probe appeared to stop transmitting after impact, but its recording tapes continued running. When engineers later examined the recordings, they found about 23 minutes of very weak signals after landing. Venera 7 had apparently bounced and come to rest on its side, leaving its antenna poorly aimed at Earth.
The mission was a landmark for planetary exploration because it supplied the first direct measurements from Venus’s surface. Venera 5 and Venera 6 had previously returned atmospheric data during descent, while Venera 8 later achieved a longer and more capable surface mission. Luna 16 was a lunar sample-return probe, not a Venus lander.