Mars 3 lands, transmits for 20 seconds, and stops
Mars 2's lander crashed and became the first human object on the surface. Mars 3 touched down intact, sent 20 seconds of signal, and went silent for good.
The Mars 2 descent module separated from its orbiter on 27 November 1971, about four and a half hours before arrival. The parachute never deployed — the accepted explanation is too steep an entry angle — and the capsule hit the surface at speed near 4°N, 47°W, carrying a pennant with the Soviet coat of arms.
Five days later the Mars 3 descent module touched down at around 13:50:35 UT on 2 December 1971, near 45°S, 158°W. Braking cone, parachute, retro-rockets and impact-absorbing foam all worked. Ninety seconds after landing it began transmitting to the orbiter overhead; twenty seconds later, at 13:52:25, the signal stopped and was never heard again. It had returned a fragment of a panorama showing no detail, at about 50 lux — dusk.
Mars 3 landed into the planet-wide dust storm that had just blinded Mariner 9, which accounts for the dim picture and may account for the silence: the suspected cause, never confirmed, is a coronal discharge in the charged, dust-laden air, which would have damaged the communications system. The mission computers could not be reprogrammed from Earth, so both landers descended in the worst conditions Mars had shown in decades.
The rest of the 1971 Soviet effort had already gone badly. Cosmos 419, launched on 10 May, never left Earth orbit: its escape-stage ignition timer had been programmed for 1.5 years instead of 1.5 hours, the burn for Mars never came, and it reentered two days later. The Mars 2 and Mars 3 orbiters worked and returned data into August 1972, but their imaging sequences were loaded before launch and ran on schedule regardless of where the cameras pointed, which during the storm was a featureless brown ceiling.
No usable science came off the martian surface for another four and a half years.