August/September 1992, Volume 1, No. 1
Thermal Emission Spectrometer ProjectMars Observer Space Flight Facility Department of Geology, Arizona State University Box 871404, Tempe, Arizona 85287-1404, U.S.A.
When the spacecraft reaches Mars in August 1993, it will go into a wide, elliptical orbit. The orbit will then be carefully adjusted over the course of four months, until it becomes nearly circular. Mars Observer's polar orbit will be Sun-synchronous, such that the spacecraft will always cross the equator at 2 AM and 2 PM local time. In December 1993, its seven science instruments will begin mapping the planet from an average altitude of 400 km (250 mi.).
Data from Mars Observer will allow a more complete comparison with the Earth, which should provide new insight as to how the climate and geology of both planets evolved. Mars Observer results will also be used in planning future missions to the Red Planet, perhaps including human exploration sometime in the 21st Century.
The Mars Observer spacecraft design is based upon communication and defense mapping satellites which routinely circle the Earth. The spacecraft was assembled under contract from NASA by the General Electric Astro-Space Division, Hightstown, New Jersey. At the time of the launch, the spacecraft's antenna, instrument booms, and solar array panels are folded close to the spacecraft bus, a box-shaped vehicle approximately 5 by 5 by 7 ft. in size. The main communications antenna is raised on an 18-ft boom to clear the 10 by 25 ft solar array, which is fully unfolded only when the spacecraft reaches Mars. The total spacecraft mass after launch is about 5400 pounds.
Mission operations for the Mars Observer Project are conducted at the Jet Propulsion Laboratory (JPL) in Pasadena, California. The Mars Observer Project Manager, David D. Evans, and the Project Scientist, Arden L. Albee, run the program at JPL. A new innovation in planetary space missions allows each of the seven science instruments to be controlled from the home institutions of the principal investigators. For example, the principal investigator for the Thermal Emission Spectrometer (TES) is Philip R. Christensen, a Professor of Geology at Arizona State University (ASU). Thus, TES will be controlled and data will be received at a facility at ASU. TES team members and participating scientists will visit ASU to operate the instrument and analyze the data.
Written by: K.S. Edgett
Text prepared by:T.E. Montoya
Original Text: August 1992 Hypertext Version: January 29, 1994