The second of three Soviet spacecraft intended for the 1962 Mars launch period, Mars 1 was the first spacecraft sent by any nation to fly past Mars. Its primary mission was to photograph the surface during a flyby from a range of between 621 to 6,835 miles (1,000 to 11,000 kilometers).

In comparison to its predecessor, the probe had a slightly different main engine (the S5.19) than the Venus probes, with a reduced propellant tank mass. The camera system, weighing 71 pounds (32 kilograms), included both 35 and 750 mm lenses and used 70 mm film. It could take up to 112 frames, stored on film and then scanned for playback to Earth.

After successful insertion into Earth orbit, the Blok L upper stage successfully fired the probe towards Mars, but immediately after engine cutoff, controllers discovered that pressure in one of the nitrogen gas bottles for the spacecraft’s attitude control system had dropped to zero (due to incomplete closure of a valve). Before all of the compressed nitrogen was lost, on Nov. 6-7, 1962, controllers were able to spin the vehicle around the axis perpendicular to the plane of the solar panels to enable a backup gyroscope system to keep the solar panels constantly exposed to the Sun during the coast phase. Further mid-course corrections, however, proved impossible.

Controllers maintained contact with the vehicle until March 21, 1963 when the probe was 66 million miles (106 million kilometers) from Earth. According to TASS (on May 16), because of the failure of orientation, “the direction of the station’s antennas toward Earth was upset.” This anomaly prevented further radio contact after March 21. Mars 1 silently flew by Mars at a distance of 122,400 miles (197,000 kilometers) on June 19, 1963.

Prior to loss of contact, scientists were able to collect data on interplanetary space (on cosmic ray intensity, Earth’s magnetic fields, ionized gases from the Sun, and meteoroid impact densities) up to a distance of 1.24 AUs. The data from Mars 1 (from November 20, 1962 to January 25, 1963) showed that once past 0.24 AUs, i.e., Earth’s radiation belts, the intensity of cosmic radiation was virtually constant.


Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.

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