Mars 4
A picture of Mars 4.
Mission typeMars orbiter[1]
COSPAR ID1973-047A Edit this at Wikidata
SATCAT no.6742
Mission duration9 days (launch day to day of last contact)
Spacecraft properties
Spacecraft3MS No.52S
Launch mass3,440 kilograms (7,580 lb) fully fueled[2]
Start of mission
Launch date21 July 1973, 19:30:59 (1973-07-21UTC19:30:59Z) UTC[3]
Launch siteBaikonur 81/23
End of mission
Last contact10 February 1974, 15:38 UTC
Orbital parameters
Reference systemHeliocentric
Flyby of Mars (failed orbiter)
Closest approach10 February 1974, 15:34 UTC
Distance1,844 km (1,146 mi)

Mars 4 (Russian: Марс-4), also known as 3MS No.52S was a Soviet spacecraft intended to explore Mars. A 3MS spacecraft launched as part of the Mars programme, it was intended to enter orbit around Mars in 1974. However, computer problems prevented orbital insertion from occurring.[4]


The Mars 4 spacecraft carried an array of instruments to study Mars. In addition to cameras, it was equipped with a radio telescope, an IR radiometer, multiple photometers, polarimeters, a magnetometer, plasma traps, an electrostatic analyzer, a gamma-ray spectrometer, and a radio probe.[5]

Built by Lavochkin, Mars 4 was the first of two 3MS spacecraft launched to Mars in 1973, being followed by Mars 5. A 3MS was also launched during the 1971 launch window as Kosmos 419. However, due to a launch failure, it failed to depart Earth orbit. In addition to the orbiters, two 3MP lander missions, Mars 6 and Mars 7, were launched during the 1973 window.


Mars 4 was launched by a Proton-K carrier rocket, a Blok D upper stage, flying from Baikonur Cosmodrome Site 81/23.[3] The launch occurred at 19:30:59 UTC on 21 July 1973, with the first three stages placing the spacecraft and upper stage into a low Earth parking orbit before the Blok D fired to propel Mars 4 into heliocentric orbit bound for Mars.

Shortly after performing a course correction on 30 July 1973, two onboard computers failed, leaving Mars 4 unable to perform maneuvers. As a result of this, it was unable to enter orbit around Mars. Twelve photographs were taken on 10 February 1974 from 15:32 UTC to 15:38 UTC as the probe flew past Mars with a closest approach of 1,844 kilometres (1,146 mi) at 15:34 UTC.[6]

Scientific Instruments

Mars 4 orbiter carried 15 scientific instruments on board to study Mars from orbital trajectory[5]

See also


  1. ^ Krebs, Gunter. "Interplanetary Probes". Gunter's Space Page. Retrieved 12 April 2013.
  2. ^ "Mars 4". NASA. Retrieved 6 December 2018.
  3. ^ a b McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 12 April 2013.
  4. ^ "Mars 4". US National Space Science Data Centre. Retrieved 12 April 2013.
  5. ^ a b Siddiqi, Asif A. (2002). "1973". Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000 (PDF). Monographs in Aerospace History, No. 24. NASA History Office. pp. 101–106. Archived (PDF) from the original on 25 September 2004.
  6. ^ Siddiqi, Asif A. (2016). Beyond Earth: A Chronicle of Deep Space Exploration 1958-2016, NASA History Program Office,