Galileo Status Report - April 1, 1996
PUBLIC INFORMATION OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
The project team has analyzed an unexpected tank pressure situation in Galileo's propulsion system that was observed after the March 14 maneuver. The problem of possible internal leakage is in the helium pressurization system and is somewhat similar to a problem observed last July. Tank pressures can be controlled by maintaining appropriate temperatures with electric heaters in the system, which requires careful management of all spacecraft electric power loads. This strategy has been applied since July. Telemetry now suggests that at least one check valve is closed. All tank pressures are within acceptable limits.
The Galileo engineers are continuing to develop and check out the new spacecraft operating system, which includes new programming for many of the science instruments as well as the attitude control and command and data computers. This mass of computer code is scheduled to be sent up to the spacecraft in May and June.
The spacecraft is performing normally, spinning at about 3 rpm, collecting interplanetary dust and magnetic-field measurements and transmitting them to Earth, together with the tape playbacks and engineering telemetry, at 16 bits per second. Galileo is now just 19 million kilometers (11.9 million miles) from Jupiter, falling back toward the planet at about 892 meters per second (2,000 mph). It is 792 million kilometers (492 million miles) from Earth.