The Galileo Magnetometer description comes from the SpaceScience Reviews instrument paper which is reproduced herewith permission from Kluwer Academic Publishers, Dordecht,Boston, London (KIVELSONETAL1992). Three appendices to the originalarticle are provided at the end of the description thatdescribe changes to the flight software and data acquisitionin the Phase 2 mission (low gain antenna mission),some of the in-flight anomalies that have occurredand their resolutions, and the MAG command dictionary.
THE GALILEO MAGNETOMETER
The Galileo Orbiter carries a complement of fields andparticles instruments designed to provide data needed toshed light on the structure and dynamical variations of thejovian magnetosphere. Many questions remain regarding thetemporal and spatial properties of the magnetosphericmagnetic field, how the magnetic field maintains corotationof the embedded plasma and the circumstances under whichcorotation breaks down, the nature of magnetic perturbationsthat transport plasma across magnetic shells in differentparts of the system, and the electromagnetic properties ofthe jovian moons and how they interact with themagnetospheric plasma. Critical to answering these closelyrelated questions are measurements of the dc and lowfrequency magnetic field. The Galileo Orbiter carries afluxgate magnetometer designed to provide the sensitivemeasurements required for this purpose. In this paper, themagnetometer is described. The instrument has two boom-mounted, three-axis sensor assemblies. Flipper mechanismsare included in each sensor assembly for the purpose ofoffset calibration. The microprocessor controlled datahandling system produces calibrated despun data that can beused directly without further processing. A memory systemstores data for those periods when the spacecraft telemetryis not active. This memory system can also be used forstoring high time-resolution snapshots of data.
The jovian magnetosphere envelopes the planet in a vastcocoon around which the solar wind is deflected in itsoutward flow from the sun. The magnetic field of the planetitself brings order to the plasma contained in themagnetosphere, constraining the ions and electrons to movein orbits imposed by electromagnetic forces.
In the 1970's, four spacecraft: Pioneer 10 and 11, andVoyager 1 and 2 traveled through the magnetosphere ofJupiter and provided information on the properties of thecha