This Week on Galileo - November 11-17, 1996
Galileo completed its fouth pass through the Jupiter system this weekend. Late Saturday into Sunday, the spacecraft performed an orbital trim maneuver to correct errors in its orbital path. These errors are incurred when the actual spacecraft path through the Jupiter system is a little different than planned.
The end of the Callisto encounter marks the end of the first (of two) mini-tours to be performed by the Fields and Particles (or magnetospheric) intruments. Recall that a mini-tour is a continuous survey (or collection of data) through at least one complete orbit. This particular mini-tour started at the beginning of the Ganymede-2 encounter. The Fields and Particles survey is scheduled to restart just prior to Galileo's next satellite encounter with Europa (12/14). The next mini-tour, however, is not scheduled to start until the summer of 1997.
Playback of Callisto encounter data started this weekend and will continue through the start of the Europa encounter. This week focuses on observations of closest approach to Callisto itself. Included in these observations are global maps, known regions: Asgard, Valhalla and Catena and various areas of interest: multiple rings, bright spots, scarps and plains. This variety will allow scientists to compare the different terrain on Callisto's surface. Data return of this closest approach period also includes high resolution data from the Fields and Particles intruments which will allow study of the interaction of Callisto with Jupiter's magnetosphere as well as determination of whether Callisto has a magnetic field of its own.
In addition to playback, early in the week, the spacecraft performs a small turn to keep its antenna pointed toward Earth. Recall that the spacecraft points itself in one planned direction by using an unmoving reference as a guide, like the stars. With respect to this direction, the Earth drifts out of its antenna's view and a small turn is required to keep communications possible.