This Week On Galileo - May 18-24, 1998
With just about two weeks remaining before its next close encounter with Jupiter's moon Europa, Galileo spends this week continuing to process and transmit to Earth science data gathered during its previous encounter in late March. Data processing is interrupted once this week, on Wednesday, to turn the spacecraft to keep the radio antenna pointed toward Earth, and to perform regular maintenance on the spacecraft's propulsion system.
Only two observations are on the processing and transmission schedule this week. Both were performed by the spacecraft's camera, or solid state imaging subsystem, and contain science information describing Europa. The first is a high-resolution picture of the Tyre Macula crater region. This region contains a circular feature about 140 kilometers (87 miles) in diameter (about the size of the island of Hawaii) and is thought to be the site where an asteriod or comet hit Europa's ice crust. The second observation contains a region that shows a transition from bright plains to pull-apart wedges. These features suggest that the surface crust has been separated and filled with material from below the surface.
Last week, flight team engineers sucessfully identified and corrected a minor error in an update to the attitude control computer's onboard software that had been performed on Sunday, May 3. The original software update had not been performing as expected. Testing performed after this latest update has shown that the software is now performing as designed and the attitude control computer should be able to correct and use the output from the gyroscope that has been behaving anomalously since December 1997.