Galileo shares recent Io encounter with Earth
NASA STATUS REPORT
Posted: Feb. 29, 2000
During data playback, the spacecraft computer retrieves the data stored on the tape recorder, then processes and packages the data, and subsequently transmits the data to Earth. Only one observation is on the playback docket this week. The Fields and Particles instruments continue the return of a 2-3/4 hour high resolution recording of the Io torus that was taken starting 3-1/2 hours prior to the Io flyby. The Fields and Particles instruments are comprised of the Dust Detector, Energetic Particle Detector, Heavy Ion Counter, Magnetometer, Plasma Detector, and Plasma Wave instrument. The observation contains measurements of the plasma, dust, and electric and magnetic fields within the Io torus, and will be used increase the knowledge of the structure and dynamics of the torus region. The torus is a ring-shaped region of intense plasma and radiation activity with its inner edge bounded by Io's orbit. The torus is actively maintained by Jupiter's strong electric and magnetic fields and Io's constant supply of volcanic particles.
On a final note, Galileo is operating normally this week after suffering a safing event late last week. The spacecraft safing is believed to have been caused by an erroneous power reset signal, which happens regularly during each encounter. You might remember that new software was installed on Galileo to allow the spacecraft to recover autonomously from this type of anomaly. Unfortunately, the new software must be disabled during tape recorder playback. Galileo suffered two other power reset signals during last week's encounter, and the new software allowed encounter commands to continue executing unhindered, protecting the time-critical data gathering phase. This means that the Galileo team expects that all planned observations of Io were completed successfully.
Explore the net
The Galileo Mission - official home page at JPL
Countdown to Io 27 - computer simulated views and other information about Galileo's encounter.
The Galileo Europa Mission - fact sheet, frequently asked questions and more.
Clickable Europa Maps - view close ups of the moon's surface
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