Jet Propulsion Laboratory (U.S.). Mars Observer Project Office.

After a 17 year gap since the last mission to Mars, NASA launched JPL's 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.

Mars Observer's mission was to study the surface, atmosphere, interior and magnetic field of Mars from the Martian orbit. The mission was designed to operate for one full Martian year (687 Earth days) to permit observations of the planet through its four seasons.

The mission specific objectives were the following: (1) determine the global elemental and mineralogical character of Mars' surface material, (2) define the planet's global topography and gravitational field, (3) establish the nature of the Martian magnetic field, (4) determine the time and space distribution, abundance, sources and sinks of volatile material and dust over a seasonal cycle, (5) explore the structure and aspects of the circulation of the Martian atmosphere.

The spacecraft also carried a radio relay package designed to receive information from the planned Mars Balloon Experiment carried on the planned Soviet Mars 1994 mission for retransmission back to Earth.

Communication with the spacecraft was lost on August 22, 1993 as it was preparing to go into orbit around Mars and no significant scientific data was returned.

From the description of Mars Observer Library Records Collection, 1988-1993. (Jet Propulsion Laboratory Library and Archives). WorldCat record id: 733101963