Cassini Significant Event Report

For Week Ending 07/06/01

The most recent spacecraft telemetry was acquired from the Goldstone
tracking station on Wednesday, July 4. 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.

Recent spacecraft activities included two Radio and Plasma Wave Science
(RPWS) high frequency receiver calibrations, two Magnetospheric Imaging
Instrument (MIMI) Low Energy Magnetospheric Measurement Subsystem (LEMMS)
exercises, a high water mark clear, and Imaging Science Subsystem (ISS)
photometric calibration and dark frame imaging activities. The Visual and
Infrared Mapping Spectrometer (VIMS) supplemental heater was also powered
on via real-time command to maintain the needed thermal conditions for the

A slow time memory readout of the Reaction Wheel Assembly (RWA) and a RWA
Friction Test were performed. The Friction Test is a periodic test that
measures the performance of each of the four reaction wheels and checks
for any abnormal wear. The Attitude and Articulation Control Subsystem
team is still performing detailed analysis of the test results, however
preliminary analysis indicate that all four wheels continue to operate

Final sequence products for the C27 sequence were compiled, released, and
approved for uplink. The sequence was then successfully uplinked to the
spacecraft and verified to be active, with the sequence scheduled to begin
execution in the coming week.

The Instrument Operations / VIMS team conducted Integration Test
Laboratory (ITL) testing of the new VIMS flight software. Once the data
are retrieved from ITL data analysis will begin. This analysis includes
check out of the ground software's ability to process the data collected
as output from the test of the new flight software.

The Radio Science Team held their post-Project Science Group meeting in
Oxford England.

Multi Mission Image Processing Laboratory (MIPL) is developing a new,
web-based, realtime telemetry processing system to support ISS and VIMS
data processing during Tour. MIPL held a two-day peer review that
included, on the second day, a series of demonstrations of the new

The Mission Planning analysis of Titan flyby minimum altitudes was
presented at the Mission Planning Forum, with the group assigning action
items and identifying next steps in preparing for Titan flybys.

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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