Mars 3 — first soft landing on Mars

On 2 December 1971, a Soviet landing capsule fell through a Martian sky thick with dust. The planet below was in the grip of the largest dust storm ever observed, but the automated sequence could not be changed: aeroshell, parachute, then retrorocket, swung on a chain beneath the descending craft. At about 13:50:35 UT the capsule thumped down in the Ptolemaeus Crater region at 45 degrees south. Four petal covers opened. Ninety seconds after landing, the lander began transmitting to its orbiter passing overhead. Humanity had landed working hardware on Mars.

Then, after roughly 14.5 seconds of image data, the signal simply stopped, and no further transmission was ever received. The only picture returned was a grey, featureless fragment in which nothing could be identified. The cause of the failure was never determined; engineers suspected electrical discharge in the raging dust storm or damage to the antenna system. Five days earlier, the twin Mars 2 lander had crashed during its own descent, becoming the first human artifact on Mars, but never speaking.

The achievement was still extraordinary. Launched on 28 May 1971 by a Proton-K rocket, the combined Mars 3 spacecraft was a 4,650-kilogram flagship; its descent module weighed 1,210 kilograms fueled, with a 358-kilogram landing capsule. Strapped aboard was PrOP-M, a 4.5-kilogram walking rover that would have shuffled across the surface on skis at the end of a 15-metre umbilical, the first rover ever sent to Mars. It never got the chance to move. The orbiter, meanwhile, kept working into 1972, returning imaging and atmospheric data.

The story gained a coda four decades later. In 2013, a group of Russian space enthusiasts scouring images from NASA's Mars Reconnaissance Orbiter identified a set of features matching the Mars 3 landing: a bright 7.5-metre spot consistent with the parachute, plus candidates for the heat shield, retrorocket, and the lander itself, its petals seemingly open. The little capsule that spoke for fourteen and a half seconds may have been found, sitting where it fell, waiting out the dust.