Mars Observer

Mars Observer
Artist rendering of Mars Observer in orbit around Mars
NamesMars Geoscience Climatology Orbiter
Mission typeMars orbiter
OperatorNASA / JPL
COSPAR ID1992-063A
SATCAT no.22136
Websitescience.nasa.gov
Mission duration330 days
Mission failure
Spacecraft properties
BusMars Observer bus (AS-4000-TIROS/DMSP hybrid)
ManufacturerGeneral Electric
Astro Space
Launch mass1,018 kg (2,244 lb)
Power1,147 watts
Start of mission
Launch dateSeptember 25, 1992, 17:05:01 (1992-09-25UTC17:05:01Z) UTC
RocketCommercial Titan III/TOS
Launch siteCape Canaveral LC-40
ContractorMartin Marietta
End of mission
Last contactAugust 21, 1993, 01:00 (1993-08-21UTC02Z) UTC
Orbital parameters
Reference systemAreocentric
Semi-major axis3,766.159 km (2,340.183 mi)
Eccentricity0.004049
Inclination92.869°
EpochDecember 6, 1993
Planned
Flyby of Mars (failed insertion)
Closest approachAugust 24, 1993

Mars Observer was an American robotic space probe launched by NASA on September 25, 1992 to study the surface, atmosphere, climate and magnetic field of Mars. The spacecraft was developed and managed by the Jet Propulsion Laboratory.

The project originated with a 1984 proposal for a new Mars mission, originally titled the Mars Geoscience Climatology Orbiter. As the first and ultimately only mission in the Planetary Observer program, its design was based on earlier Earth-orbiting satellites, including the TIROS and DMSP series. Seven scientific instruments were included.

On August 21, 1993, during the interplanetary cruise phase, communication with Mars Observer was lost, three days prior to its scheduled orbital insertion around Mars. Attempts to re-establish communications with the spacecraft were unsuccessful. Investigators concluded that the likely cause of the failure was a rupture of the fuel pressurization tank in the spacecraft's propulsion system. Several instruments designed for Mars Observer, including the Mars Orbiter Camera, were successfully flown on subsequent missions, beginning with Mars Global Surveyor in 1996.