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Mars Observer
Mars Observer Mission to Mars

Mission Type: Orbiter
Launch Vehicle: Titan III (CT-4)
Launch Site: ESMC / launch complex 40
Spacecraft Mass: 2,573 kg
Spacecraft Instruments:
1) imaging system
2) thermal emission spectrometer
3) pressure modulator infrared radiometer
4) laser altimeter
5) magnetometer/electron reflectometer
6) gamma-ray spectrometer
7) radio science experiment
8) Mars balloon relay receiver
Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, by Asif A. Siddiqi, NASA Monographs in Aerospace History No. 24

NASA's HEASARC Observatories,

Mars Observer was designed to carry out a high-resolution photography mission of the Red Planet over the course of a Martian year (687 days) from a 378 x 350-km polar orbit. Mars Observer carried a suite of instruments to investigate Martian geology, atmosphere and climate in order to fill in gaps in our knowledge of planetary evolution. A mere 31 minutes after launch, the new Transfer Orbit Stage (TOS) fired to boost the spacecraft on an encounter trajectory with Mars.

After a 725-million-km voyage lasting eleven months, just two days prior to planned entry into Mars orbit, the spacecraft suddenly fell silent at 01:00 UT on 22 August 1993.

Despite vigorous efforts to regain contact, Mars Observer remained quiet. When the spacecraft did not reestablish command as a result of a stored program that was designed to do so in case of five days of silence, mission planners finally gave up hope on salvaging the mission. The results of a five-month investigation proved to be inconclusive, but one likely cause of the catastrophic failure may have been a fuel line rupture that could have damaged the spacecraft's electronics, throwing the vehicle into a spin.

Before contact with the spacecraft was lost, approximately two months of total data from the gamma ray spectrometer was successfully collected, including spectral observations of one burst.

Editor's Note: This mission profile was adapted from an originally published mission profile in Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000, by Asif A. Siddiqi, NASA Monographs in Aerospace History No. 24.

Key Dates
25 Sep 1992:  Launch (17:05:01 UT)
22 Aug 1993:  Contact Lost (01:00 UT)
27 Aug 1993:  End of Mission
Status: Mission Lost at Mars
Fast Facts
Mars Observer Facts Mars Observer was to observe Mars over the course of a Martian year (687 days).

The spacecraft's journey to Mars took a little less then one Earth year.

After a 17-year gap since its last mission to the Red Planet, the United States launched Mars Observer on 25 September 1992.
People Spotlight
Steve Squyres Steve Squyres
Steve is best known as principal Investigator for the Mars Exploration Rovers, but he's contributed to many of the greatest robotic missions. Read More...
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Last Updated: 24 Jan 2011