Mars Observer

Mars Observer

Artist rendering of Mars Observer in orbit around Mars
Mission type	Mars orbiter
Operator	NASA / JPL
COSPAR ID	1992-063A
SATCAT no.	22136
Website	archived
Mission duration	331 days Mission failure
Spacecraft properties
Bus	Mars Observer bus (AS-4000-TIROS/DMSP hybrid)
Manufacturer	General Electric Astro Space
Launch mass	1,018 kilograms (2,244 lb)
Power	1,147 watts
Start of mission
Launch date	September 25, 1992, 17:05:01 (1992-09-25UTC17:05:01Z) UTC
Rocket	Commercial Titan III/TOS
Launch site	Cape Canaveral LC-40
End of mission
Last contact	August 21, 1993, 01:00 (1993-08-21UTC02Z) UTC
Orbital parameters
Reference system	Areocentric
Semi-major axis	3,766.159 kilometers (2,340.183 mi)
Eccentricity	0.004049
Inclination	92.869 degrees
Epoch	Planned December 6, 1993
Flyby of Mars (failed insertion)
Closest approach	August 24, 1993

The Mars Observer spacecraft, also known as the Mars Geoscience/Climatology Orbiter, was a robotic space probe launched by NASA on September 25, 1992, to study the Martian surface, atmosphere, climate and magnetic field. On August 21, 1993, during the interplanetary cruise phase, communication with the spacecraft was lost, three days prior to the probe's orbital insertion. Attempts to re-establish communications with the spacecraft were unsuccessful.