PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. PHONE (213) 354-5011
FOR RELEASE
MAY 5, 1983

       Engineers at Jet Propulsion Laboratory today may hear the first transmissions from NASA's Viking Lander 1 (the Thomas A. Mutch Memorial Station) since last November.

       Listen-only tracking will begin at 10:03 a.m. (PDT) and continue until 11:05 a.m. Engineers will use the 64-meter (210-foot) Mars antenna at the Goldstone Deep Space Network station in the California desert.

       Communications with Viking Lander 1 were lost in November 1982, and engineers at JPL have repeatedly sent commands in efforts to contact the station. The command sequences were based on detailed studies of possible failure modes.

       Today's events are predicated on the assumption that the lander may still be operating. The lander contains an internal program in its memory that could automatically initiate transmissions to Earth. The program is initiated after nine weeks pass without commands from Earth. Today is the first opportunity for such automatic transmissions to occur.

       Two more opportunities exist to contact the lander in case it is operating but can not initiate communications on its own. The first will be on May 13. Engineers will send commands to the lander ordering it to switch to different components of its transmitter. The final set of commands will be sent on May 20. Those commands will attempt to switch the transmitter to the last possible configuration of components.

       Viking Lander 1 was renamed the Mutch Memorial Station in memory of Dr. Thomas A. Mutch, former Viking Lander Imaging Team leader, and former Associate Administrator of NASA's Office of Space Science and Applications. Dr. Mutch disappeared during an attempt to climb Nun Kun, peak in the Himalaya, in September 1980.

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4/27/83 DB
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