Cassini Significant Event Report

For Week Ending 11/09/01

The most recent spacecraft telemetry was acquired from the Goldstone
tracking station on Wednesday, November 7. The Cassini spacecraft is in an
excellent state of health and is operating normally. Information on the
spacecraft's position and speed can be viewed on the
"Present Position"
web page.

The C28 sequence has completed execution, and the C29 sequence was
uplinked last week and began execution on Sunday November 4. Recent
instrument activities include two Radio and Plasma Wave Science High
Frequency Receiver calibrations, Imaging Science Subsystem (ISS) scattered
light characterization and dark frame observations, a RADAR Periodic
Instrument Maintenance activity, a Magnetospheric Imaging Instrument Ion
and Neutral Camera collimator plate test, and the beginning of the Visual
and Infrared Mapping Spectrometer (VIMS) radiator test. Engineering
activities taking place onboard the spacecraft this week include a
transition from Reaction Wheel Assembly (RWA) to Reaction Control
Subsystem control, an RWA unload, and transition back to RWA control for
the VIMS Radiator test.

The C30 sequence activity kicked off this week with the beginning of the
Subsequence Generation Phase. This sequence is planned to have lower
levels of activity, such that Cassini personnel can focus on tour
planning. The C30 sequence is planned to contain an ISS mini-sequence with
a VIMS ride-along, and a turn to point the Cosmic Dust Analyzer in the
spacecraft ram direction to increase their science return.

The Instrument Operations (IO)/ISS team returned the Composite Infrared
Spectrometer (CIRS) support images, dark frames, and scattered light test
data. The support images were processed and have been sent to ISS and
CIRS for analysis. The IO/ISS team continued its camera haze anomaly
investigation based on the C28 decontamination results.

The Attitude Control Subsystem (ACS) Flight Software (FSW) team has
delivered version A8.4.0 of ACS FSW to the test labs as scheduled. The
version for the Flight Software Development System was also released. The
team is exercising the standard test set on the new delivery, which closes
seven flight software changes.

Mission Planning and the Spacecraft Operations Office completed a study of
the Cassini hydrazine propellant budget, with results showing a margin of
60 kg of hydrazine at the end of the four-year nominal mission. Science
Planning will reassess their propellant usage strategy in the coming
months in light of this study.

The final report for the Titan Science Uplink Verification activity was
published, and a full suite of Target Working Team meetings was held last
week to continue with the integration of the tour.

Cassini Information Management System (CIMS) developers from Southwest
Research Institute met with the Cassini Uplink Operations/ Mission
Sequence Subsystem (MSS) and Science Planning representatives, and have
agreed to plans for the next several deliveries of CIMS in support of the
Science Operations Plan development. A discussion was held with Mission
Support & Services Office (MSSO) representatives to review CIMS
performance and compatibility issues with the MSSO proposed mid-tier

Cassini staff supported the NASA Quarterly Program Review, which was
attended by personnel from NASA Headquarters and line management.

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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