Cassini Significant Event Report

For Week Ending 09/07/01

The most recent spacecraft telemetry was acquired from the Madrid tracking
station on Wednesday, September 5. 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 include two Radio and Plasma Wave Science
High Frequency Receiver calibrations, a Probe S-Band antenna pattern
calibration, a Command & Data Subsystem Solid State Recorder memory load
partition repair, and an Imaging Science Subsystem 77/78 Taurus
observation. Real-time commands were uplinked to the spacecraft as planned
to turn off the Ka-Band Exciter and Ka-Band Traveling Wave Tube Amplifier,
transition from the Reaction Wheel Assembly (RWA) to the Reaction Control
Subsystem for attitude control, and power off the RWA.

The first system mode test of the Probe Relay critical sequence was
successfully completed. This represents a major milestone in the Probe
Relay sequence development process. In addition, the Saturn Orbit
Insertion (SOI) sequence successfully passed a bus fault system mode test
where the remote terminal simulator was used to simulate a bus fault.

The C28 Preliminary Sequence Integration and Validation meeting was held,
with the C28 sequence approved for uplink. The C28 sequence was radiated
and registered on board the spacecraft late this week, and will activate
over the coming weekend.

The Mission Planning team delivered the kickoff package for C30 to science
planning, which will begin the C30 Science Planning Team process early
next week.

The Radio Science (RS) Ops Team supported the Cassini Deep Space Station
(DSS)-25 Upgrade Task and the Network Monitor and Control (NMC) 1.3 Task
in demonstrating the use of NMC 1.3 during a live Cassini track over
DSS-25. Simultaneous Ka-band and X-band uplinks were controlled and
monopulse monitor data was streamed to the RS Ops Team in their Mission
Support Area.

A software Delivery Coordination Meeting was held to review the Cassini
Information Management System (CIMS) 1.4 software delivery. The primary
new functionality is the ability to produce a time-ordered-listing of user
data and either view it or save it to a file.¿

The Mission Assurance website and Risk Management Tool have been rolled
out into operations. User accounts have been established and risk owners
have been tasked with reviewing and giving a status of their assigned

The Development Management Office finalized the commitment of capabilities
to be developed for SOI and Probe Relay phases.

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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