yee@trident.arc.nasa.gov (Peter E. Yee) (05/26/89)
MAGELLAN STATUS
May 25, 1989
Plans are being made to place in Magellan's Cruise 4 and 5
computer command sequences information to help develop a solution
to the rocket engine module overheating problem. Starting with
Cruise-4, which will be uploaded on June 9, the spacecraft will
be turned 180 degrees around an axis through the medium-gain
antenna (MGA) to collect thermal data in a new attitude.
Also, two new stars will be added to the star calibration
sequence in Cruise-4. The spacecraft will scan the stars of a
different spectral class to assist in adjusting the star-scanner
acceptance criteria and on-board attitude determination. Those
scans will not be updated, however.
The twice daily momentum wheel desaturations and the daily
star calibration were performed routinely Wednesday.
Project has determined the time of day Magellan will reach
its aim point at Venus on August 10, 1990. Without further
trajectory correction it would be 10:30 a.m. PDT. Another
trajectory correction maneuver scheduled for December, however,
will skew that time by several minutes.
SPACECRAFT
Distance From Earth (mi) 3,056,363
Velocity Geocentric 5,706 mph
Heliocentric 60,169 mph
One Way Light Time 15.2 sec