Flight Status Report

Friday, 13 March 1998

Aerobraking operations continue to proceed smoothly for the Mars Global Surveyor spacecraft. Since arrival at Mars last September, Surveyor has completed 174 orbits, and aerobraking has reduced the period of revolution around the planet from its initial high of 45 hours down to its current value of 13.2 hours. The flight team anticipates that aerobraking will continue to proceed unimpeded due to the low probability of another major dust storm at Mars.

The flight team is currently preparing for the temporary suspension of aerobraking and the reactivation of the science payload. This transition will occur about two weeks from now when the orbit period has been reduced to 11.6 hours. At that time, Surveyor will fire its thrusters to raise the low point of its orbit out of the atmosphere. This temporary aerobraking hiatus will allow the science teams to collect data during the spring and summer months of this year. In addition, the hiatus is also necessary so that Mars will be in the proper position in its orbit around the Sun when aerobraking finishes and mapping commences next spring.

After a mission elapsed time of 491 days from launch, Surveyor is 218.63 million miles (351.85 million kilometers) from the Earth and in an orbit around Mars with a high point of 12,453 miles (20,041 km), a low point of 72.8 miles (117.2 km), and a period of 13.2 hours. The spacecraft is currently executing the P175 command sequence, and all systems continue to perform as expected. The next status report will be released between March 25th and April 1st.

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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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