Galileo Status Report - June 4, 1996
PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Among the data being returned are long-awaited measurements of the Io torus, an invisible doughnut-shaped ring around Jupiter populated in part by charged ions of oxygen and sulfur emanating from the volcanic moon Io. The measurements Galileo made of this energetic region are of great interest to scientists attempting to understand the complex interplay of magnetic forces and matter in Jupiter's magnetosphere.
Planning continues for Galileo's upcoming June 27 encounter with the moon Ganymede. Yesterday's data return from the spacecraft included an optical navigation image of Ganymede and a reference star to help fine-tune targeting of Galileo's 844-kilometer (524-mile) altitude flyby of that big moon. Used for navigation purposes only, the image is the product of new computer processing capabilites on the spacecraft that allow Galileo to send back only the information required to show the spacecraft is properly targeted and that the jovian satellites are where navigators calculate them to be.
Ganymede is the largest satellite in the solar system. With a diameter of 5,300 kilometers (about 3,300 miles), it is three-quarters the size of Mars.
The return of the Io data and the optical navigation frame were enabled by the extensive new software that was radioed to the Galileo spacecraft last month. Galileo is now equipped to perform its orbital mission with this new software.
Galileo is now 10.8 million kilometers (6.7 million miles) from Jupiter, and 653 million kilometers (405.7 million miles) from Earth. One-way communication time is 37 minutes. Galileo's speed in orbit around Jupiter is 3.2 kilometers per second, about 7,300 miles per hour.