MAGELLAN Sig Events - 4-1-94 

             Magellan Significant Events for Week Ending 04/01/94

*1.  The Magellan spacecraft went into CDS safing on Monday, March 28th, when
it tried to execute an invalid instruction.  The spacecraft was back in normal
operations with S-band communications by mid-Monday, and X-band communications
were restored on Tuesday.

*2.  The incident was caused by a delayed command uplink to perform a memory
readout which over-wrote a portion of active memory earlier on March 16th.
Procedures to avoid a recurrence have been implemented.

 3.  During the four orbits in safing the spacecraft cooled down since it was
not performing the "heat" maneuvers on each orbit, but all systems were nominal
including the gyros which had exhibited fluctuating motor currents when
temperatures got below 50 deg.  C.

 4.  The orbit number reached 12000 on Wednesday, March 30th. (The actual
count, however, is 111 orbits less since the numbering started at 100 and was
adjusted by 11 during the early in-orbit checkout.)

                 Magellan Significant Events for Next Week

*1.  Between April 4th and April 12th, 1994, 10 Orbit Trim Maneuvers (OTMs)
will be performed to change the orbit from approximately 530 x 184 km to 390 x
220 km in order to improve the data acquired by the gravity experiment (on the
apoapsis side of the orbit).
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