Mars 5
Mission typeMars orbiter[1]
COSPAR ID1973-049A Edit this at Wikidata
SATCAT no.6754
Mission duration7 months 3 days (launch to last contact)
Spacecraft properties
Spacecraft3MS No.53S
Launch mass4,650 kg[2]
Start of mission
Launch date25 July 1973, 18:55:48 (1973-07-25UTC18:55:48Z) UTC[3]
Launch siteBaikonur 81/24
End of mission
Last contact28 February 1974 (1974-03-01)
Orbital parameters
Reference systemAreocentric
Periareon altitude1,760 kilometres (1,090 mi)
Apoareon altitude35,300 kilometres (21,900 mi)
Inclination35.3 degrees
Epoch12 February 1974
Mars orbiter
Orbital insertion12 February 1974, 15:45 UTC[4]

Mars 5 (Russian: Марс-5), also known as 3MS No.53S was a Soviet spacecraft launched to explore Mars. A 3MS spacecraft launched as part of the Mars programme, it successfully entered orbit around Mars in 1974. However, it failed a few weeks later.[4]


The Mars 5 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 analyser, a gamma-ray spectrometer, and a radio probe.[5] The Three cameras were a 52mm Vega, a 350mm Zulfar and a panoramic camera.[6]

Built by Lavochkin, Mars 5 was the second of two 3MS spacecraft launched to Mars in 1973, following Mars 4. 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 5 was launched by a Proton-K carrier rocket with a Blok D upper stage, flying from Baikonur Cosmodrome Site 81/24.[3] The launch occurred at 18:55:48 UTC on 25 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 5 into heliocentric orbit bound for Mars.

The spacecraft performed course correction manoeuvres on 3 August 1973 and 2 February 1974.[5]

Mars orbit

The probe reached Mars on 12 February. At 14:44:25 the spacecraft's engines ignited to begin its orbit insertion burn, which successfully placed it into an Areocentric orbit with a periapsis of 1,760 kilometres (1,090 mi), an apoapsis of 32,586 kilometres (20,248 mi), and 35.3 degrees inclination.[4][5]

The spacecraft's pressurised instrument compartment began to leak as soon as the spacecraft entered orbit around Mars, which controllers believed to be the result of a micrometeoroid impact during orbital insertion. It ceased operations on 28 February, having returned 180 photographic frames, 43 of which were of usable quality.[5] The probe's original planned lifetime in Mars orbit had been three months.[7] The probe's gamma ray spectrometer measured the uranium, thorium and potassium content of the surface the probe passed over and found they were similar to Igneous rocks on Earth.[7] The exact ratios of the elements varied with the age of the surface.[7] Mars 5's Infrared radiometer reported a daytime surface temperature of between -44°C and -2°C.[6][7] Night time temperatures were measured at -73°C.[7]

The probe also made a number of observations of Mars's atmosphere.[7] It found an ozone layer at an altitude of 30km and observed clouds.[7]

See also


  1. ^ Krebs, Gunter. "Interplanetary Probes". Gunter's Space Page. Retrieved 12 April 2013.
  2. ^ "Mars 5". Retrieved 6 December 2018.
  3. ^ a b McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 12 April 2013.
  4. ^ a b c "Mars 5". US National Space Science Data Centre. Retrieved 12 April 2013.
  5. ^ a b c d 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.
  6. ^ a b Harvey, Brian (2007). Russian Planetary Exploration History, Development, Legacy and Prospects. Springer-Praxis. p. 154. ISBN 9780387463438.
  7. ^ a b c d e f g Harvey, Brian (2007). Russian Planetary Exploration History, Development, Legacy and Prospects. Springer-Praxis. pp. 161–165. ISBN 9780387463438.