Mars 1M No.1

Did You Know?

• A possibly apocryphal story states that after being removed from the spacecraft, the Spectroreflectometer failed to detect life.
• The spacecraft would have reached nearest approach to Mars on 13 May 1961.

Background

After the Luna 2 and Luna 3 triumphs in 1959, Soviet confidence soared, particularly because the United States had not yet completed a successful lunar mission. Two more lunar attempts in April 1960 ended in failure due to rocket problems, but program leaders assured Nikita Khrushchev they would achieve new space milestones, including trips to Mars and Venus. The 8K72 rocket used for the Luna flights lacked the power to reach either planet, so a new, stronger version of the R-7 had to be built. A rushed ten-month effort created the 8K78, later named the Molniya booster, which combined an R-7 core with upgraded first-stage engines and a larger upper stage called the Blok I. It also added a fourth stage, the Blok L, designed to ignite from a parking orbit for better trajectory control than the direct path used on Luna missions. In February 1960, Sergei Korolev proposed adding landers to the 1M probes. These landers were said to be about the size of a television and no heavier than 285 kg, meant to separate just before the flyby and descend to Mars. Sounding rockets tested models at 50 km altitude during the summer of 1960, but the plan turned out too ambitious and was postponed. The two Mars probes reached Baikonur on 30 August 1960. Ground checks on 9 September caused numerous system breakdowns, making a launch impossible during the favorable late September Mars window. The Blok L stage was behind schedule, though early ground tests showed it working well. The rocket was set up on Launch Complex 1 on 8 October. Because of the delay, the payload had to be lighter; the camera and a life-detection instrument were taken out due to malfunctions and weight limits. The spacecraft would have made its closest pass to Mars on 13 May 1961.

Launch

The Molniya 8K78 rocket, serial number L1-4M, made its first flight on 10 October 1960, carrying Mars 1M No.1 as its payload. This new R-7 variant swapped the Vostok's Blok-E third stage for a Blok-I, and added a new Blok-L fourth stage. Liftoff from Baikonur's Site 1/5 occurred at 14:27:49 UTC. The rocket steered downrange without issue. The first stage's new 8D74K engines performed correctly, and all systems operated as planned through the core stage burn.

End of mission

The rocket’s third stage developed a resonant vibration at T+309.9 seconds during the second stage of flight. This vibration broke a gyroscope and wrecked the carrier rocket’s attitude control system. The horizon sensor then detached from the booster, and the rocket pitched down 7° from its intended path. Controllers ordered the third stage to shut down after five minutes and 24 seconds. The spacecraft climbed to 120 km altitude before falling back into the atmosphere, where it broke apart. Debris scattered across Siberia, 4,800 kilometers downrange. It never reached low Earth orbit.