The dust storm that the Mars Global Surveyor spacecraft successfully side stepped last month has largely faded in intensity. Although haze and other effects in the Martian atmosphere continue to be observed, the core of the storm has dissipated, and the Surveyor spacecraft has resumed its normal pace of aerobraking. However, the flight team's atmospheric advisory group will continue to monitor conditions closely because the dust storm season on Mars extends well into next year.

Over the last 10 days, eight passes through the atmosphere have reduced the altitude of the orbit's high point by 1,239 miles (1,994 km) and decreased the period of revolution around the red planet by 1.9 hours.

In addition to aerobraking operations, members of the flight team are currently developing operational scenarios for detailed science observations between May 1998 and September 1998. During that time, aerobraking will be temporarily placed on hiatus. This pause will provide the science teams with an opportunity to conduct detailed observations of the red planet free from the operational constraints imposed by atmospheric operations. The final mapping orbit will be reached in March 1999.

After a mission elapsed time of 411 days from launch, Surveyor is 196.1 million miles (315.63 million kilometers) from the Earth and in an orbit around Mars with a high point of 23,229 miles (37,384 km), a low point of 76.1 miles (122.4 km), and a period of 27.7 hours. The spacecraft is currently executing the P71 command sequence, and all systems continue to perform as expected. The next status report will be released on Friday, January 9th.

Happy new year from the Mars Global Surveyor flight operations team!

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Status report prepared by:

Office of the Flight Operations Manager
Mars Surveyor Operations Project
NASA Jet Propulsion Laboratory
California Institute of Technology
Pasadena, CA 91109
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