Galileo Status Report - April 15, 1996
PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
Orbiter spacecraft measurements of the Io plasma torus, made a few hours before the spacecraft arrived at Jupiter, remain to be played back starting in June when the spacecraft has been reprogrammed with its new software.
Later this week a new test sequence for the tape recorder will condition the tape and further explore the limits of safe use of the tape. A fairly conservative procedure for data recording will be used for the Ganymede encounter in June. The better the engineers understand the tape and the way it sticks, the better use they can make of it in later encounters, project officials said.
Telemetry indicates that Galileo is operating normally. The spacecraft is spinning at about 3 rpm, and transmitting science and engineering data to the Deep Space Network at 16 bits per second. All the instruments are in good condition, and the magnetometer and dust detector are returning science data about three times per week.
Development and testing of the new flight software is progressing reasonably well. It involves reprogramming of the main flight computers in the command and data subsystem and attitude and articulation control system and in nine science instruments. The engineers believe that the process of installing this in the Galileo spacecraft, starting in May, will take less time than planned, though a few enhancements due this week will delay the start of loading. The software will be used in playing back the orbiter's Io torus data, beginning in June.
The Galileo spacecraft is 18.3 million kilometers (11.3 million miles) from Jupiter, approaching the planet at about 1.2 kilometers per second (2,648 mph). It is 758 million kilometers (471 million miles) from Earth, so that spacecraft signals take more than 42 minutes to reach the Deep Space Network antennas.