Galileo Status Report - July 19, 1996
PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011 http://www.jpl.nasa.gov
Included in the data recently returned by Galileo is an image of the moon Io that shows changes there due to volcanic activity. As of noon yesterday, 92 images had been received from the Ganymede encounter period. The images are edited and compressed onboard the spacecraft. Engineers report that the image data compression ratio is running from as low as 1.5:1 for high-resolution Ganymede observations to as high as 20:1 for some Jupiter atmosphere images. An estimated 40 percent of the recorded encounter science data has been returned.
Browsers of the Galileo home page at http://www.jpl.nasa.gov/galileo can see the some of the recently returned images of Ganymede, Io and the Great Red Spot.
The Near Infrared Mapping Spectrometer (NIMS) has recovered from a glitch that had prevented data playback from that instrument's observations during the Ganymede encounter. The NIMS instrument software was reloaded on July 17th and the processor started successfully yesterday. The team is hopeful of beginning the playback of NIMS data from the Ganymede encounter by the first of August after the return of other instrument readings from the flyby has been completed.
Instrument engineers are also developing a patch to fix a "bug" in software that runs the Energetic Particle Detector (EPD), which sensed an anomaly and requested to be placed safe shut-off mode just prior to the Ganymede encounter. The problem appears to affect the monitoring of the EPD's high-voltage state. On July 17th, the flight EPD prime power was turned on again, its computer memory loaded and verified and it is currently in a safe operating state. The EPD high voltage was intentionally left off and is intended to remain off pending the loading of the software patch.
Galileo is 635.8 million kilometers (about 395 million miles) from Earth and about 8 million kilometers (about 5 million miles) from Jupiter. It is traveling at a speed of about 8,900 kilometers per hour (about 5,500 miles an hour) relative to Jupiter. Currently, it takes 35 minutes and 21 seconds for Galileo's radio signals to reach Earth.