From: Jet Propulsion Laboratory
Posted: Wednesday, October 23, 2002
The Pace Quickens The science observation sequence for Galileo's final satellite encounter begins this week. On Monday, October 21, the Fields and Particles suite of instruments is turned on and configured to collect continuous data for the next three weeks. During this time, the spacecraft passes the tiny inner moon Amalthea, and passes closer to Jupiter than any spacecraft since Pioneer 10 and 11 sped by nearly three decades ago. The instruments participating in the Galileo data collection are the Dust Detector, the Energetic Particle Detector, the Heavy Ion Counter, the Magnetometer, the Plasma Subsystem, and the Plasma Wave Subsystem.
While these data are being collected, occasional gaps in the ground communications antenna coverage require the data to be stored in an on-board computer memory buffer, and when that buffer fills, the data are copied onto the tape recorder for later playback. To prepare for these buffer dumps, the tape is moved on Monday to the correct position to begin recording. Over the next two weeks the buffer is dumped to tape 14 times.
On Thursday, October 24, a test of the gyroscopes that help determine the spacecraft attitude is performed. This test will help engineers decide if any of the software parameters that are used to process the gyro data need to be updated before the maneuver that will occur next week.
On Friday, October 25, routine maintenance of the propulsion system is performed. Also on that day the spacecraft closes to within 100 Jupiter radii (7.1 million kilometers or 4.4 million miles) of the giant planet.
Finally, on Sunday, October 27, the sequence of commands that will govern spacecraft activity during the week of the close Amalthea flyby will be transmitted to Galileo.
For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at one of the following URL's:
// end //