Mars 4

Mars 4
Mission type Mars orbiter[1]
Operator Lavochkin
COSPAR ID 1973-047A[2]
SATCAT № 6742[2]
Spacecraft properties
Spacecraft 3MS No.52S
Manufacturer Lavochkin
Start of mission
Launch date 21 July 1973, 19:30:59 UTC[3]
Rocket Proton-K/D
Launch site Baikonur 81/23
End of mission
Last contact 30 July 1973
Orbital parameters
Reference system Heliocentric
Flyby of Mars (failed orbiter)
Closest approach 10 February 1974, 15:34 UTC
Distance 1,844 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.

Spacecraft

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 analyser, a gamma-ray spectrometer, and a radio probe.[4]

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.

Launch

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 manoeuvres. As a result of this, it was unable to enter orbit around Mars. A small amount of data was returned as the probe flew past Mars on 10 February 1974, with a closest approach of 1,844 kilometres (1,146 mi) at 15:34 UTC.[4]

References

  1. ↑ Krebs, Gunter. "Interplanetary Probes". Gunter's Space Page. Retrieved 12 April 2013.
  2. ↑ 2.0 2.1 "Mars 4". US National Space Science Data Centre. Retrieved 12 April 2013.
  3. ↑ 3.0 3.1 McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 12 April 2013.
  4. ↑ 4.0 4.1 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.