Cassini Significant Event Report

For Week Ending 04/26/02

The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Tuesday, April 23. 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.

Magnetospheric and Plasma Science data collection has resumed following last week's Probe checkout. Quiet cruise activities continued with minimal onboard activities being performed.

The Satellite Orbiter Science Team (SOST) and Project Science Group - Satellite Surfaces Working Group met to make a decision on the Enceladus flybys in Orbits 3, 4, and 11. A plan was developed and SOST will request a change to the flyby altitude for the non-targeted Enceladus flyby on Orbit 3 with the understanding that this may be very difficult for the Project to accommodate.

A Planetary Data System (PDS) archive workshop was held this week at the Huygens Science Working Team meeting in Paris, France. The meeting was attended by Huygens team Principal and Co-Investigators, Interdisciplinary Scientists, and Cassini and PDS archive representatives. The workshop was an introduction to the work involved in archiving with the PDS, and contained examples of Cassini orbiter work and demonstrations of Galileo and Pathfinder imaging CDs. Huygens team members responded positively to the presentation of proposed roles and responsibilities, which included help in generating instrument description files based on the European Space Agency SP-1177 document.

Additional progress was made in archiving for the Visual and Infrared Mapping Spectrometer (VIMS), Ultraviolet Imaging Spectrograph (UVIS), and Cosmic Dust Analyzer (CDA). JPL Imaging node representatives traveled to Tucson to meet with the VIMS team to discuss archiving. Samples of UVIS data products were sent to the PDS Atmospheres node for review, and the iterative process for reviewing label contents and file structures has begun. Small Bodies PDS Node and CDA personnel met to further define data products. CDA has identified EKernel and CKernel data to archive.

Instrument Operations reported that the Events Kernel System Design document D-22965 was distributed last week. In addition, unit and system testing of E-Kernel software components has begun. Testing is going well, and development is on schedule.

Uplink Office (ULO) personnel presented a tutorial on the use of the Solid State Recorder Management Tool to users from the Spacecraft Operations Office, Mission Planning, and Science Planning. Work on Mission Sequence Subsystem (MSS) D8.0.1 began this week. This patch delivery is intended to release the Science Opportunity Analyzer and SSR Management tools, synchronize the versions of the Inertial Vector Propagator/Kinematic Prediction Tool in use by the Pointing Design Tool (PDT) and ACS operations, and address miscellaneous clean-up of items in PDT, APGEN, SEG and SEQGEN that are needed for the Science Operations Plan development process.

ULO chaired a meeting where plans for the development of the Automated Sequence Process (ASP) were discussed and agreed upon. A preliminary version of ASP is scheduled for delivery in late September '02. The software will perform basic processing of a command request, but not include automated notification. Prototype development work is underway, with preliminary requirements to be finished and final coding started in late April '02. ULO began work on a presentation outlining a long-term plan for the Cassini Information Management System (CIMS) through the end of its development. The purpose is to inform users of the functionality available at critical milestones, and provide a forum to discuss processes currently under construction that CIMS will be required to support.

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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