Cassini Significant Event Report

For Week Ending 12/13/02

The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, December 11. 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.

An autonomous Solid State Recorder Memory Load Partition repair was performed on board the spacecraft
this week. Additional instrument activities included execution of the Radio and Plasma Wave (RPWS) looper
program #1, RPWS High Frequency Receiver calibrations, flight software normalization for Imaging Science
Subsystem v1.3, Cosmic Dust Analyzer (CDA) v9.0, and Visual and Infrared Mapping Spectrometer (VIMS)
v5.1 flight software loads, uplink of RPWS v2.6 and CDA v9.0.2 flight software, and the start of Gravitational
Wave Experiment (GWE) #2. GWE#2 will last for 40 days, and will require continuous DSN support. The
first few days of GWE #2 proceeded nominally until a power glitch at the DSS-25 station interrupted the
X-band and the Ka-band transmitters. However, both transmitters were operational again within about an
hour. On the third day, the Ka-Band Translator (KaT) dropped lock and went to the bad region twice during
a pass. On both occasions, commands to power cycle the KaT were uplinked to the spacecraft, and by one
round-trip-light-time later, the KaT had locked successfully. Since then, operations have been nominal.

The Science Operations Plan implementation activity for tour sequences S15/S16 kicked off this week. These
sequences cover Orbit 16 through Orbit 19. The Cruise 37 Science Planning Team development activity also
kicked off this week. The process completes in February 2003. Both activities have planned a 2-week down
time during the Christmas and New Years holiday period.

The Instrument Operations team hosted their monthly Instrument Operations Working Group meeting.
Presentations included an overview of presentation content for the October 2003 Operations Readiness
Review and Virtual Private Network and Remote Terminal Interface Unit status.

The topics at this week's Mission Planning forum included study results of distant occultations and close rock
encounters during tour, and a proposed addition of two maneuvers during cruise. Trajectory Correction
Maneuvers 19a and 19b would occur in September of 2003, and would allow the flight team an opportunity to
exercise processes to be used in tour, demonstrate "first time" capabilities that will be needed during Saturn
Orbit Insertion, and provide an opportunity for an additional Reaction Control Subsystem maneuver, the
previous one having been performed in May of 1999.

The Spacecraft Operations Office held a Flight Software/Critical Sequence Monthly Management Review.
Participants were office and program management, the Attitude Control, Command and Data System,
Integrated Test Lab, and Systems teams.

A Delivery Coordination Meeting/Software Requirements Certification Review was held this week for VIMS
flight software version 6.1. The software has been cleared for uplink to the spacecraft, and the Assisted Load
Format file has been delivered from the Program Software Library to the Integrated Test Laboratory for testing
and uplink preparation. The software is planned to be uplinked to the spacecraft in early January 2003.

Acceptance testing for most of the Uplink Operations Mission Sequence Software version D9.0 software set
has begun. Testing for the Pointing Design Tool is expected to start by the end of the month.
Outreach attended the National Science Teachers Association western regional conference in Albuquerque,
New Mexico December 5-7. Multiple workshops were held on building integrated science and literacy
curricula, blending standards into existing curricula, and current trends in education and education reform.
Many textbooks and activity packages were available for participant review.

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 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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