This Week On Galileo - May 11-17, 1998
Galileo spends most of the week processing and transmitting to Earth science information stored on the spacecraft's onboard tape recorder. All of the data on this week's schedule contains information describing Jupiter's icy moon Europa. The data set returned this week was gathered by the spacecraft's camera, near-infrared spectrometer and suite of fields and particles instruments during the spacecraft's close flyby of the moon, just over 6 weeks ago.
Some data from last week's schedule slipped into this week when Galileo released antenna time at the Deep Space Network's 70-meter antenna in Canberra, Australia. The antenna time was released to support radio frequency observations of the newly identified gamma ray burst you may have heard about in the news. The burst was located in a relatively close galaxy and the Canberra antenna was considered a key part for very long baseline interferometry (VLBI) observations required to study the event.
Last week's efforts to change the attitude control computer's onboard software have encountered a glitch. It appears that the onboard software was successfully modified, but the effect on the gyroscopic data is not as expected. The flight team will continue to gather and analyze spacecraft engineering data to determine what went wrong. Another gyroscope performance test is scheduled this Friday.
This week's information processing and transmission activities continue to retrieve data from a section of the onboard tape recorder that has already been accessed once this orbit. This second processing and transmission opportunity allows data gaps to be filled, re-processing of data with different parameters, or selection of entirely new data.
On the data return schedule we find two observations by the spacecraft's camera of a region of Europa characterized by dark spots. Together they will provide a stereo topographic view of the area. The camera team also returns an observation of a region containing characteristic triple bands. Finally, the camera team returns an observation designed to provide photometric measurements of Europa's surface. Photometry is the measurement of light intensities which can then be used to help identify the different materials on the surface of Europa.
The near-infrared spectrometer team contributes to this week's schedule by scheduling the return of an observation of a region of Europa containing dark spots and pull-apart wedges. The observation is expected to provide more information on the materials that make up this region of Europa. Finally, the fields and particles instruments return measurements that will add to the repository of information describing the interaction of Jupiter's magnetic and electric fields with Europa.