Encyclopedia Astronautica
Mars M-73



mars67.jpg
Mars 6, 7 / M-73
Credit: © Mark Wade
Russian Mars lander. 4 launches, 1973.07.21 (Mars 4) to 1973.08.09 (Mars 7). The M-73 spacecraft series was built for 1973 Mars missions.

Due to the unfavorable position of Mars during that campaign, separate versions built: two intended to orbit Mars and map the surface, and two to land capsules. The orbiters were equipped with instrumentation to study the composition, structure, and properties of the Martian atmosphere and surface, including an imaging device, a 256 channel gamma-ray spectrometer mounted on a boom and a Lyman-Alpha photometer. The landers would have separated from their uninstrumented bus, entered the atmosphere, where a parachute opened, slowing the descent.

The lander equipment included a Lyman-Alpha photometer and a Bennett mass analyzer. Unfortunately, this entire series of spacecraft experienced failures on arrival at Mars due to pre-flight test of the electronics with helium, which resulted in degradation of the computer chips during the journey to Mars. Orbiters had a launch mass of 3444 kg, and landers 3260 kg.

Gross mass: 3,440 kg (7,580 lb).
First Launch: 1973.07.21.
Last Launch: 1973.08.09.
Number: 4 .

More... - Chronology...


Associated Countries
Associated Engines
  • KTDU-425A Isayev N2O4/UDMH rocket engine. 18.890 kN. Mars 4-7, Venera 9-16, Vega 1-2, and Phobos 1-2 maneuvering engine. Out of Production. Could be throttled to 9.86/9.5/2870. Chamber pressure 149 - 95 bar. Isp=315s. First flight 1973. More...

See also
  • Proton The Proton launch vehicle has been the medium-lift workhorse of the Soviet and Russian space programs for over forty years. Although constantly criticized within Russia for its use of toxic and ecologically-damaging storable liquid propellants, it has out-lasted all challengers, and no replacement is in sight. More...

Associated Launch Vehicles
  • Proton The Proton launch vehicle has been the medium-lift workhorse of the Soviet and Russian space programs for over forty years. Although constantly criticized within Russia for its use of toxic and ecologically-damaging storable liquid propellants, it has out-lasted all challengers, and no replacement is in sight. Development of the Proton began in 1962 as a two-stage vehicle that could be used to launch large military payloads or act as a ballistic missile with a 100 megaton nuclear warhead. The ICBM was cancelled in 1965, but development of a three-stage version for the crash program to send a Soviet man around the moon began in 1964. The hurried development caused severe reliability problems in early production. But these were eventually solved, and from the 1970's the Proton was used to launch all Russian space stations, medium- and geosynchronous orbit satellites, and lunar and planetary probes. More...
  • Proton-K/D Russian orbital launch vehicle. This four stage version of the Proton was originally designed to send manned circumlunar spacecraft into translunar trajectory. Guidance to the Block D stage must be supplied by spacecraft. The design was proposed on 8 September 1965 by Korolev as an alternate to Chelomei's LK-1 circumlunar mission. It combined the Proton 8K82K booster for the LK-1 with the N1 lunar Block D stage to boost a stripped-down Soyuz 7K-L1 spacecraft around the moon. The Korolev design was selected, and first flight came on 10 March 1967. The crash lunar program led to a poor launch record. Following a protracted ten year test period, the booster finally reached a level of launch reliability comparable to that of other world launch vehicles. More...

Associated Manufacturers and Agencies
  • MOM Russian agency overseeing development of spacecraft. Ministry of General Machine Building (Moskva, Russia), Moscow, Russia. More...
  • Lavochkin Russian manufacturer of rockets and spacecraft. Lavochkin Design Bureau, Moscow, Russia. More...

Associated Programs
  • Mars Soviet Mars probes were intended to photograph Mars on flyby trajectories, followed by Mars orbit, landing, and Phobos reconnaisance missions. Essentially all of the series failed. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • JPL Mission and Spacecraft Library, Jet Propulsion Laboratory, 1997. Web Address when accessed: here.
  • Kaesmann, Ferdinand, et. al., "Proton - Development of A Russian Launch Vehicle", Journal of the British Interplanetary Society, 1998, Volume 51, page 3.
  • "Na Mars!", Novosti Kosmonavtiki, 1996, Issue 20, page 53.
  • Vladimirov, A, "Tablitsa zapuskov RN 'Proton' i 'Proton K'", Novosti kosmonavtiki, 1998, Issue 10, page 25.
  • National Space Science Center Planetary Page, As of 19 February 1999.. Web Address when accessed: here.

Associated Launch Sites
  • Baikonur Russia's largest cosmodrome, the only one used for manned launches and with facilities for the larger Proton, N1, and Energia launch vehicles. The spaceport ended up on foreign soil after the break-up of Soviet Union. The official designations NIIP-5 and GIK-5 are used in official Soviet histories. It was also universally referred to as Tyuratam by both Soviet military staff and engineers, and the US intelligence agencies. Since the dissolution of the Soviet Union the Russian Federation has insisted on continued use of the old Soviet 'public' name of Baikonur. In its Kazakh (Kazak) version this is rendered Baykonur. More...

Mars M-73 Chronology


1973 July 21 - . 19:30 GMT - . Launch Site: Baikonur. Launch Complex: Baikonur LC81/23. LV Family: Proton. Launch Vehicle: Proton-K/D. LV Configuration: Proton-K/D 261-01.
  • Mars 4 - . Payload: M-73 s/n 52S. Mass: 4,650 kg (10,250 lb). Nation: USSR. Agency: MOM. Program: Mars. Class: Mars. Type: Mars probe. Spacecraft: Mars M-73. USAF Sat Cat: 6742 . COSPAR: 1973-047A. Failed; did not enter Martian orbit as planned; intended to be a Mars orbiter mission. Mars 4 reached Mars on 10 February 1974. Due to use of helium in preflight tests of the computer chips, which resulted in degradation of the chips during the voyage to Mars, the retro-rockets never fired to slow the craft into Mars orbit. Mars 4 flew by the planet at a range of 2,200 km. It returned one swath of pictures and some radio occultation data. Final heliocentric orbit 1.02 x 1.63 AU, 2.2 degree inclination, 556 day period.

1973 July 25 - . 18:55 GMT - . Launch Site: Baikonur. Launch Complex: Baikonur LC81/24. LV Family: Proton. Launch Vehicle: Proton-K/D. LV Configuration: Proton-K/D 262-01.
  • Mars 5 - . Payload: M-73 s/n 53S. Mass: 4,650 kg (10,250 lb). Nation: USSR. Agency: MOM. Program: Mars. Class: Mars. Type: Mars probe. Spacecraft: Mars M-73. USAF Sat Cat: 6754 . COSPAR: 1973-049A. Mars probe intended to enter Martian orbit and comprehensively photograph Mars. Parameters are for Mars orbit. Mars 5 reached Mars on 12 February 1974 and was inserted into a 1760 km x 32,586 km orbit. Due to computer chip failures the orbiter operated only a few days and returned atmospheric data and images of a small portion of the Martian southern hemisphere.

1973 August 5 - . 17:45 GMT - . Launch Site: Baikonur. Launch Complex: Baikonur LC81/23. LV Family: Proton. Launch Vehicle: Proton-K/D. LV Configuration: Proton-K/D 281-01.
  • Mars 6 - . Payload: M-73 s/n 50P. Mass: 4,650 kg (10,250 lb). Nation: USSR. Agency: MOM. Program: Mars. Class: Mars. Type: Mars probe. Spacecraft: Mars M-73. USAF Sat Cat: 6768 . COSPAR: 1973-052A. Mars probe intended to make a soft landing on Mars. Total fueled launch mass of the lander and orbital bus was 3260 kg. It reached Mars on 12 March 1974, separated from the bus, and entered the atmosphere, where a parachute opened, slowing the descent. As the probe descended through the atmosphere it transmitted data for 150 seconds, representing the first data returned from the atmosphere of Mars. Unfortunately, the data were largely unreadable due to a flaw in a computer chip which led to degradation of the system during its journey to Mars. When the retro-rockets fired for landing, contact was lost with the craft. Mars 6 landed at about 24 degrees south, 25 degrees west in the Margaritifer Sinus region of Mars. Bus ended up in a final heliocentric orbit 1.01 x 1.67 AU, 2.2 degree inclination, 567 day period.

1973 August 9 - . 17:00 GMT - . Launch Site: Baikonur. Launch Complex: Baikonur LC81/24. LV Family: Proton. Launch Vehicle: Proton-K/D. LV Configuration: Proton-K/D 281-02.
  • Mars 7 - . Payload: M-73 s/n 51P. Mass: 4,650 kg (10,250 lb). Nation: USSR. Agency: MOM. Program: Mars. Class: Mars. Type: Mars probe. Spacecraft: Mars M-73. USAF Sat Cat: 6776 . COSPAR: 1973-053A. Mars probe intended to make a soft landing on Mars. Mars 7 reached Mars on 9 March 1974. Due to a problem in the operation of one of the onboard systems (attitude control or retro-rockets) the landing probe separated prematurely and missed the planet by 1,300 km. The early separation was probably due to a computer chip error which resulted in degradation of the systems during the trip to Mars. Ended up in a final heliocentric orbit 1.01 x 1.69 AU, 2.2 degree inclination, 574 day period.

1974 February 10 - .
1974 February 12 - .
  • Mars 5, Mars Orbit Insertion - . Nation: USSR. Spacecraft: Mars M-73.

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