PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
FOR IMMEDIATE RELEASE

       Magellan spacecraft controllers lost contact with the Venus mapper late Thursday during the spacecraft's second test-mapping orbit after it turned to make a star calibration, officials at NASA's Jet Propulsion Laboratory said.

       JPL Magellan Project officials believe the spacecraft has automatically entered a safing mode after acquiring the wrong guide star for pointing and will begin searching for Earth direction this evening.

       The spacecraft, which begin testing its imaging radar Thursday afternoon, turned its antenna to confirm and update it attitude, and the signal was not reacquired.

       The second test orbit started at 7 p.m. PDT. Magellan completed its radar illumination of the planet's surface and started replay of the recorded data. It began a star calibration maneuver to confirm its position.

       The signal did not reappear as expected at 8:32 pm PDT, 14 minutes later, officials said.

       Project officials believe the spacecraft detected a fault and entered a protective safing mode in which it orients itself toward the sun so its solar array will continue to receive power and then finds a guide star. From that position it then turns its medium-gain antenna toward Earth.

       The spacecraft will wait for 18 hours to hear from its controllers on Earth and if no signal is received it assumes it has the wrong guide star. It will begin a search pattern to find the Earth so contact can be reestablished.

       Project officials said they would wait for the spacecraft to begin its search for Earth at 9:12 p.m. PDT.


#####


#1318