Mars 6 (), also known as 3MP No.50P was a

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nation ...

spacecraft launched to explore Mars. A 3MP bus spacecraft launched as part of the

Mars program The Mars program was a series of uncrewed spacecraft launched by the Soviet Union between 1960 and 1973. The spacecraft were intended to explore Mars, and included flyby probes, landers and orbiters. Early Mars spacecraft were small, and launche ...

, it consisted of a lander, and a coast stage with instruments to study Mars as it flew past.

Spacecraft

The Mars 6 spacecraft carried an array of instruments to study Mars. The lander was equipped with a thermometer and barometer to determine the surface conditions, an accelerometer and radio altimeter for descent, and instruments to analyse the surface material including a

mass spectrometer Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a '' mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is us ...

. The coast stage, or bus, carried a

magnetometer A magnetometer is a device that measures magnetic field or magnetic dipole moment. Different types of magnetometers measure the direction, strength, or relative change of a magnetic field at a particular location. A compass is one such device, o ...

, plasma traps, cosmic ray and micrometeoroid detectors, and an instrument to study

proton A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...

and

electron The electron ( or ) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family, and are generally thought to be elementary particles because they have no kn ...

flux Flux describes any effect that appears to pass or travel (whether it actually moves or not) through a surface or substance. Flux is a concept in applied mathematics and vector calculus which has many applications to physics. For transport ph ...

es from the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

. Built by Lavochkin, Mars 6 was the first of two 3MP spacecraft launched to Mars in 1973 and was followed by

Mars 7 Mars 7 (), also known as 3MP No.51P was a Soviet Union, Soviet spacecraft launched in 1973 to explore Mars. A 3MP bus spacecraft which comprised the final mission of the Mars programme, it consisted of a Lander (spacecraft), lander and a coast st ...

. Two orbiters,

Mars 4 Mars 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 inser ...

and

Mars 5 Mars 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. Spacecraft ...

, were launched earlier in the 1973 Mars launch window and were expected to relay data for the two landers. However, Mars 4 failed to enter orbit, and Mars 5 failed after a few days in orbit.

Launch

Mars 6 was launched by a Proton-K carrier rocket with a

Blok D Blok D (russian: Блок Д meaning Block D) is an upper stage used on Soviet and later Russian expendable launch systems, including the N1, Proton-K and Zenit. The stage (and its derivatives) has been included in more than 320 launched r ...

upper stage, flying from Baikonur Cosmodrome Site 81/23. The launch occurred at 17:45:48 UTC on 5 August 1973, with the first three stages placing the spacecraft and upper stage into a low Earth

parking orbit A parking orbit is a temporary orbit used during the launch of a spacecraft. A launch vehicle boosts into the parking orbit, then coasts for a while, then fires again to enter the final desired trajectory. The alternative to a parking orbit is ''di ...

before the Blok D fired to propel Mars 6 into heliocentric orbit bound for Mars. The spacecraft performed a course correction on 13 August 1973. Mars 6's lander separated from the flyby bus on 12 March 1974 at an altitude of from the surface of Mars. The bus made a flyby with a closest approach of . The lander encountered the atmosphere of Mars at 09:05:53 UTC, slowing from as it passed through the upper atmosphere. A parachute was then deployed to further slow the probe's descent, and

retrorocket A retrorocket (short for ''retrograde rocket'') is a rocket engine providing thrust opposing the motion of a vehicle, thereby causing it to decelerate. They have mostly been used in spacecraft, with more limited use in short-runway aircraft land ...

s were intended to fire during the last seconds before the probe reached the ground. The spacecraft returned data for 224 seconds during its descent through the Martian atmosphere. However, at 09:11:05 UTC, with the spacecraft about to fire its retrorockets in preparation for landing, all contact was lost. Due to a design flaw, a chip aboard the spacecraft had degraded during the mission, and a large amount of the data which had been returned was unusable. Mars map Viking 1 Mars 2 Mars Pathfinder Opportunity Mars 6

Mars map Viking 1 Mars 2 Mars Pathfinder Opportunity Mars 6

References

{{Use dmy dates, date=January 2014 Spacecraft launched in 1973 1973 in spaceflight 1973 in the Soviet Union Mars program Derelict satellites in heliocentric orbit 4MV 1974 on Mars

Spacecraft

Launch

See also

References