From: Jet Propulsion Laboratory
Posted: Wednesday, October 9, 2002
and there is now less than a month until Galileo makes its final fly-by of the mission, a close encounter with Jupiter's small inner satellite Amalthea, on November 5. As the pace of activity picks up, both on the spacecraft and on the ground, the pace of these reports now returns to weekly.
The flight team is now hard at work putting the finishing touches on the activity sequence for the encounter, and planning for contingency actions. The harsh environment near Jupiter has upset our plans in the past, and we are relying on our 12 years of experience with the spacecraft, and our anticipation of the worst that Jupiter can throw at us, to shore up any vulnerabilities in our plans.
On Friday and Saturday, October 4 and 5, a test was performed to verify a method of maintaining Galileo's knowledge of its position and spin rate deep within Jupiter's high radiation environment. High radiation levels interfere with the star scanner, which uses the positions of bright stars to determine Galileo's attitude and position. To counter this effect, Galileo's attitude control computer is told to "hibernate" for several hours, allowing it to continue reporting pointing and spin rate of the spacecraft without relying on either the star scanner or its radiation-sensitive gyros.
On Friday, October 11, Galileo performs the last update to its orientation prior to the encounter. This is a fairly large turn in place of slightly over 9 degrees, to keep the communications antenna pointed towards Earth, and simultaneously to orient the spacecraft to take the best advantage of the geometry of the flyby for the measurements to be taken by the Fields and Particles instruments. The spacecraft will remain at this orientation until the end of planned mission operations in mid-January 2003.
Ongoing activities for the spacecraft include maintaining the condition of the on-board tape recorder and continued data collection by the Dust Detector, the Magnetometer, and the Extreme Ultraviolet Spectrometer instruments.
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:
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