Past Missions -
Launch: September 25, 1992
Mass: 2,573 kilograms (5,672 pounds)
Science instruments: High-resolution camera, thermal emission spectrometer, laser altimeter,
magnetometer/electron reflectometer, pressure modulator infrared radiometer, gamma ray spectrometer, radio
After a 17-year gap since its last mission to the red planet, the United States launched Mars Observer on
September 25, 1992. The spacecraft was based on a commercial Earth-orbiting communications satellite that had
been converted into an orbiter for Mars. The payload of science instruments was designed to study the geology,
geophysics and climate of Mars.
The mission ended with disappointment on August 22, 1993, when contact was lost with the spacecraft shortly
before it was to enter orbit around Mars. Science instruments from Mars Observer are being reflown on two other
orbiters, Mars Global Surveyor and 2001 Mars Odyssey.