Cassini Weekly Significant Events for 02/14/02 – 02/20/02

The most recent spacecraft telemetry was acquired from the Goldstone
tracking station on Wednesday, February 20. The Cassini spacecraft is in
an excellent state of health and is operating normally. Information on
the present position and speed of the Cassini spacecraft may be found on
the “Present Position” web page located at
http://www.jpl.nasa.gov/cassini/english/where/

Instrument activities this week include a Radio Science Subsystem (RSS)
Ultra Stable Oscillator characterization, and Periodic Instrument
Maintenance.

Spacecraft activities this week included the completion of the
Spacecraft Operations Office (SCO) procedure to change the fault
protection safing response default telemetry mode to 10 bps, and load
module index patches to RAM for both Command & Data Subsystem (CDS)
strings and the SSR. Operations personnel received official
notification of the changes upon completion of the procedure.
Additional spacecraft activities included a memory readout of online CDS
state matrix, an AACS Clear High Watermark, and an autonomous CDS Solid
State Recorder memory load partition repair.

SCO Power & Thermal personnel reported observing that the Imaging
Science Subsystem (ISS) had increased in temperature by about 10 deg C,
and was drawing an additional 1.5W of power. ISS investigated and
determined a possible Narrow Angle Camera (NAC) CCD sensor failure,
which, in turn, led to a false reading of a cooler temp and turned ON
the CCD performance heater. The ISS team is working a recovery plan for
next week to power cycle the NAC and Wide Angle Camera (WAC), and reload
flight software. It is hoped that this activity will reset the sensor
and that no further action will be necessary.

The C31 background sequence has solidified and further changes are not
anticipated prior to uplink. An Integrated Test Laboratory (ITL)
procedure walkthrough for the Radio and Plasma Wave Science (RPWS), and
Ultraviolet Imaging Spectrometer (UVIS) flight software uploads was held
and the necessary files have been generated for next week’s test.

A three day technical design and risk review for Saturn Orbit Insertion
began this week. Presentations will be made by members of SCO, Mission
Planning, and Mission Assurance.

A Mission Sequence Subsystem D8 Module Functionality Design Review was
held this week. The review was geared toward science users describing
the functionality of the modules to be implemented in this delivery. No
significant issues were brought up in the review. Participants have
until the end of the week to submit any additional issues or concerns.

A delivery review was held for Multimission Image Processing Laboratory
software Version 27.0. Several Cassini specific upgrades to ISS and
Visual and Infrared Mapping Spectrometer (VIMS) functionality were
delivered and accepted by Deep Space Mission Services.

The RPWS FSW 2.5.0 and UVIS FSW 1.3.0 ALF text files were approved for
Uplink at a Delivery Coordination Meeting Software Requirement
Certification Review.

Cassini is a cooperative project of NASA, the European Space Agency and
the Italian Space Agency. The Jet Propulsion Laboratory, a division of
the California Institute of Technology in Pasadena, Calif., manages the
Cassini mission for NASA’s Office of Space Science, Washington, D.C.