Cassini Significant Event Report

For Week Ending 04/28/00

The most recent spacecraft telemetry data was acquired from the Goldstone
tracking station on Monday, 04/24. The Cassini spacecraft is in an
excellent state of health and is operating normally. The speed of the spacecraft can be viewed on the "Where is Cassini Now?" web page.

Activities this week included a CDA decontamination heater activity, and a
playback of the Radio Science Subsystem (RSS) High Gain Antenna (HGA) pattern
calibration activity. This event executed successfully and RSS reported that
everything went well for both the X-band and Ka-band calibrations.
Additional activities included an RSS Ultra Stable Oscillator (USO)
characterization and HGA boresight calibration, change from Reaction Wheel
(RWA) to Reaction Control Subsystem (RCS) control mode, and Periodic
Instrument Maintenance. After the maintenance activity, the RPWS, MAG, and
CDA instruments powered on and loaded flight software and instrument
expanded blocks (IEBs).

This week Cassini passed by the orbit of Comet Wild 2 (pronounced Vild).
As meteor streams may be associated with the orbits of comets it was hoped
that the Radio and Plasma Wave Science Subsystem (RPWS) instrument on board
Cassini would detect an increase in micrograin hits. The instrument team
is still analyzing data from the pertinent time frame. The CDA instrument
team reports no particle hits during the portion of this period when their
instrument was turned on.

All ten of the new Ops SOPCs have been checked out and configured and are
ready for shipping to the remote science team sites.

A DTF-21 data flow test was conducted which tested two CDS Version 7 flight
software data modes which will be patched into CDS Version 5 on board the
spacecraft for use in C19 and C20. The official test report is pending but
the initial results indicate that the test was successful.

The kick-off meeting for the Cruise 21 sequence was held Monday, 4/24.

The Discovery channel is planning a special on moons in the solar system.
Cassini personnel have been asked to provide input on Saturn's moons and
moon-ring interactions for this episode

Additional information about Cassini-Huygens is online at

Cassini will begin orbiting Saturn on July 1, 2004, and release its piggybacked Huygens probe about six months later for descent through the thick atmosphere of the moon Titan. Cassini-Huygens is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Office of Space Science, Washington, D.C.

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