Mars 4
Soviet Mars orbiter foiled by computer failure.
Last updated
Mars 4 (Марс-4), also called 3MS No.52S, was a Soviet Mars probe. Launched under the Mars programme, it aimed to go into orbit around the planet in 1974, but a computer malfunction kept it from doing so.
Spacecraft
The first of two 3MS orbiters built by Lavochkin for the 1973 Mars window was Mars 4, with Mars 5 following. Its instrument payload included cameras, a radio telescope, an infrared radiometer, several photometers and polarimeters, a magnetometer, plasma traps, an electrostatic analyzer, a gamma-ray spectrometer, and a radio probe. A previous 3MS, launched in 1971 as Kosmos 419, never left Earth orbit due to a launch failure. The same 1973 window also saw two 3MP lander missions, Mars 6 and Mars 7.
Launch
Mars 4 lifted off on a Proton-K carrier rocket with a Blok D upper stage from Baikonur Cosmodrome Site 81/23 at 19:30:59 UTC on 21 July 1973. After the first three stages placed the spacecraft and upper stage into low Earth parking orbit, the Blok D fired to send Mars 4 into heliocentric orbit toward Mars. Following a course correction on 30 July 1973, two onboard computers failed, leaving the probe unable to perform maneuvers and thus unable to enter Mars orbit. On 10 February 1974, it took twelve photographs between 15:32 and 15:38 UTC as it flew past Mars, making its closest approach of 1844 km at 15:34 UTC.
More in Derelict Satellites in Heliocentric Orbit
Sources
Compiled from Wikipedia and the sources listed below. Text from Wikipedia is available under CC BY-SA 4.0; this entry is adapted from it.
- Wikipedia: Mars 4 (CC BY-SA 4.0).
Spotted an error? Know more?
Reader corrections go straight into our review queue. Suggest an edit · How this site is sourced