Cassini Significant Event Report

For Week Ending 05/25/01

The most recent spacecraft telemetry was acquired from the Goldstone
tracking station on Sunday May 20. The Cassini spacecraft is in an
excellent state of health and is operating normally. Safing recovery
procedures concluded this week, with all the instruments successfully
turned on and the C26 sequence restarted early May 24. Information on the
spacecraft's position and speed can be viewed on the
"Present Position"
web page.

The C27 Sequence Virtual Team held the Subsequence Generation/Sequence
Change Request Approval Meeting.

The Huygens Recovery Task Force (HRTF) held its fifth meeting this week,
with the Cassini Program hosting the meeting in the Pasadena area. For the
first time, members of the Cassini orbiter science team were present along
with the Huygens science team and the HRTF. The orbiter instruments were
well represented and several interdisciplinary scientists were also
present. The HRTF used the opportunity to brief the orbiter scientists on
the various recovery options, their potential for science return and their
potential impact on the Cassini/Huygens mission. The Huygens science teams
presented the results of their analysis of the various data return
scenarios and the effect the scenarios would have on the goals for the
probe experiments. Both the low altitude and high altitude scenarios were
further refined and actions were assigned for follow-on studies. The next
meeting will be at European Space Research & Technology Centre (ESTEC) in
Noordwijk, Holland at the end of the month.

As part of the ongoing web consolidation effort, a new internal Cassini
web portal has been established. Significant improvements have been made
in the format and layout of the information. However, the portal is not
meant to be static, and Cassini users have been encouraged to supply
feedback so that the system can continue to evolve to meet the needs of
the project

Per schedule, the Attitude Control Flight Software Development team
delivered version A8.3.0 of the Attitude and Articulation Control
Subsystem (AACS) Flight Software (FSW) to the Integrated Test Lab for
further test. This is the last scheduled delivery for the AACS FSW prior
to the soft freeze scheduled for July.

Mission Assurance has refined and updated the Program's Anomaly Reporting
Plan. The revised plan and process were presented to the Cassini Design
Team (CDT) for review and approval. Changes to the existing Incident,
Surprise, and Anomaly (ISA) form were also discussed. An agreed upon
list of changes will be forwarded to the JPL Problem Reporting System
group for assessment and implementation.

A prototype web interface to the Event (E) Kernels was demonstrated at the
EKernel Working Group. Positive feedback from users has been received
regarding the usefulness of the tool.

Revision G of the Anomaly Response Plan was released for review this
week. Modifications include desirable changes identified during the
Jupiter sub-phase.

Cassini's Distributed Object Manager (DOM) system has proposed to migrate
their data to an alternate underlying distributed file system. The Mission
Support & Services Office (MSSO) and System Engineering (SE) teams have
begun work with the Telecommunications and Mission Operations Directorate
(TMOD)/Deep Space Mission Systems (DSMS) to determine the best solution
and review impacts to the Cassini ground system.

Mission Assurance conducted the first Cassini Risk Team meeting this week
to begin evaluating and converging on the Significant Risk List (SRL).
The forum provided a chance for free exchange of information concerning
potential risks to the Mission as well as consensus on the risks, their
ratings and mitigation efforts. Time only allowed for half of the items
on the SRL to be covered, so a follow-on meeting will be conducted to
finish this activity. Once completed, the agreed to SRL will be placed
into the on-line Risk Management Tool for tracking, continuous assessment
and reporting purposes.

The Instrument Operations (IO) Visual and Infrared Mapping Spectrometer
(VIMS) personnel attended the VIMS science team meeting in Tucson, which
included discussions of calibration, flight rules, interface issues,
planning tools and tour planning.

IO hosted a representative from Probe Operations for a week of Project
training. Classes included a Security Briefing and Voice Net Operations
taught by MSSO; Spacecraft, Planet, Instruments, C-matrix, and Events
kernels (SPICE) overview by Navigation Ancillary Information Facility
(NAIF) personnel; Cassini Information Management System (CIMS) and a
Sequence Virtual Team (SVT) Overview given by Uplink Operations (ULO);
Multimission Ground Data System (MGDS) by TMOD; and Problem Reporting and
Anomaly Response taught by SE. The SVT overview was videotaped in Von
Karman Auditorium. Future distribution of this tape on an as needed basis
will provide wider opportunities for training new project members.

On Saturday and Sunday 19-20 May, JPL sponsored the annual "Open House,"
with Cassini Outreach coordinating the Cassini team effort. This year,
over 65,000 people from throughout Southern California attended the
events. Over 50 educator product and program requests were submitted to
Cassini Education Outreach on Saturday alone.

Two new 20-slide sets have been completed for the Cassini Mission. Sets
are available to Project staff through the Cassini Outreach Office.
Additional sets and non-Cassini staff can order sets through
Finley-Holiday Films. The new sets are "Saturn System" (JPL-52) and "A
Trip to Saturn" (JPL-126). The new slide sets will also be posted in the
Gallery section of the Cassini web site. Additionally, the Cassini 1/37th
paper scale model of the spacecraft is the featured resource on the Space
Science Education Resource Directory located at:

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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