MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
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http://www.jpl.nasa.gov

MARS GLOBAL SURVEYOR MISSION STATUS - May 7, 1999

NASA's Mars Global Surveyor spacecraft returned to normal mapping operations Wednesday night, May 5.

The spacecraft is healthy and all of its science instruments are turned on. A gimbal, or hinge, on the spacecraft's dish-shaped high-gain antenna still has a restriction that limits its range of motion, but this will have no effect on the mission until next February when the Mars-to-Earth geometry will again prevent the antenna from pointing continuously at Earth. Engineers are looking at options for conducting the mission after February so that there will be a minimal impact on how much science data the mission can collect and send to Earth.

At 7:45 a.m. Pacific time today, Global Surveyor fired its small thrusters for about two minutes in order to fine-tune its orbit around Mars. The mapping orbit was designed so that the spacecraft does not fly over precisely the same swath of Martian landscape, or "ground track," from one week to the next. The spacecraft must fire its thrusters every few months to keep the necessary ground-track separation. This is especially important now since the science team is in the process of an intensive four-week campaign to acquire stereo images of the planet.