This Week On Galileo - March 31 - April 5, 1998
The remaining five days of this week continue to be busy for the Galileo spacecraft, even though it has just completed a science encounter. Among other activities, Galileo begins to process and transmit to Earth pictures and science information gathered this past weekend as the spacecraft flew past Jupiter and its moons. The series of flybys included flying over Europa's surface at a distance of 1645 kilometers (1022 miles).
During the week, the spacecraft will execute two activities designed to further understand and possibly circumvent the anomalous behavior exhibited by the attitude control subsystem. The first of these, performed on Tuesday, is designed to collect gyroscope data to track the degradation of the gyro's performance. A repeat of the performance test is planned later in the orbit, far from Jupiter's intense radiation environment, in hopes of determining whether the degradation rate is time dependent or radiation dependent, or possibly dependent on both. The second activity is performed on Wednesday and will provide engineers with data they require to complete the design of a flight software upgrade that could allow the spacecraft to operate on the single gyroscope that is functioning correctly.
This week's processing and transmission to Earth of science information contains two sets of pictures obtained by the spacecraft's camera of Jupiter's fiery moon Io. The first set of pictures shows color views of Io's north and south pole regions. The pictures will improve the color knowledge of these regions by providing more than a factor of 3 greater resolution than obtained during Galileo's primary mission, 3 kilometers (1.8 miles) per picture element and 10 kilometers (6.2 miles) per picture element, respectively. Monochrome pictures as good as 2.5 kilometers (1.5 miles) per picture element were obtained in the primary mission, but the color in these new images will be critical to identifying surface materials. The second set of images provides a preliminary look at a region of Io that is planned to be imaged at much higher resolution in October 1999. Both of these image sets will also help scientists to refine observation plans for Io in late 1999.
Data processing and transmission to Earth is paused for a few hours on Thursday as the spacecraft executes a flight path correction. This is the first flight path correction since before this past weekend's flybys.