MEDIA RELATIONS OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov

Mars Global Surveyor Mission Status
April 23, 1999
       Engineers will conduct another test tonight on NASA's Mars Global Surveyor spacecraft to check the temperature of the hinges on the high-gain telecommunications antenna in an attempt to understand if part of a thermal blanket might be obstructing its movement. The spacecraft remains in good health and the science instruments are turned off while engineers analyze the hinge.

       While engineers continue to study the nature of the obstruction, they plan to proceed with the mapping mission next week. The science instruments will be turned back on Wednesday, April 28 and the next day the spacecraft will begin a one-week mapping campaign with the antenna in a fixed position. On May 6, when Mars and the Earth are at favorable angles from each other, the spacecraft will return to a normal mapping mission that will use the antenna in its steerable mode to send continuous data to Earth.

       Flight controllers say they could conduct a normal mapping mission through February 2000, when the geometry between Mars and Earth again becomes unfavorable, with telecommunications limited due to the restricted motion of the antenna hinge. After that, the spacecraft would need to return to mapping with the antenna in a fixed position if the obstruction has not been resolved. The Surveyor scientists prefer to map with a steerable antenna, as opposed to a fixed antenna, because twice as much data can be returned to Earth in a given period.

       Mars Global Surveyor is managed by JPL for NASA's Office of Space Science, Washington, DC. JPL's industrial partner is Lockheed Martin Astronautics, Denver, which developed and operates the spacecraft. JPL is a division of the California Institute of Technology.

       Further information about the mission is on the Internet at http://mars.jpl.nasa.gov/mgs/

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