Significant Event Report for Week Ending 6/20/2003

Cassini Significant Event Report

For Week Ending 06/20/03

The most recent spacecraft telemetry was acquired from the Canberra tracking station on Wednesday, June 18. 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.

Final activities for the C37 background sequence included execution of the Radio Science Subsystem (RSS) Ka-band exciter and Ka-band traveling wave tube amplifier power-off, and a Magnetometer (MAG) and Magnetospheric Imaging Instrument (MIMI) plasma environment observation. Cruise sequence C38 began execution on Saturday, June 14th. Initial activities included a MAG calibration, Radio and Plasma Wave Science (RPWS), Ultraviolet Imaging Spectrograph, and MIMI instrument expanded block (IEB) loads, an RPWS high rate observation, RPWS high frequency receiver calibration, execution of an RPWS Saturn orbit insertion test cyclic that will run until June 24th, a Ka-Band power on, an attitude control constraint monitor update, and execution of a MIMI cyclic. Both the RPWS and MIMI cyclics are first time events.

The RSS Solar Conjunction Experiment #2 began on Sunday June 17th. It will run for thirty days until July 15th with daily Goldstone DSN support and additional coverage from the Canberra and Madrid stations. As of Tuesday, June 17, the Ka-band Translator (KaT) has been operating the in a region where it cannot lock on the uplink. The radio science team is using previously developed contingency commands to cycle the KaT power in order to restore it to the appropriate operating region. Coherent X-band and Ka1 data have been successfully acquired

Cruise sequence C39 science planning activities completed on June 13th with a hand off package delivered to Uplink Operations (ULO). C39 sequence development is underway with a kick-off meeting and the release of subsequences for the teams to populate.

Events this week for the S14 Science and Sequence Update Process (SSUP) Verification and Validation (V&V) activity included delivery from the instrument teams of IEB load Spacecraft Activity Sequence Files for the SSR, receipt and response to a new DSN allocation file, preparation for the Science Allocation Panel meeting to be held next week, release of the merged sequence product for initial review, and the third V&V status meeting.

The Integrated Test Laboratory (ITL) completed two significant tests. One was the first complete run of the Saturn Orbit Insertion critical sequence demonstration. The demo will execute on the spacecraft starting on July 21, 2003. The second test completed was the Reaction Wheel Assembly-4 (RWA-4) checkout, with all commands and associated procedures verified. RWA-4 checkout is currently scheduled for July 7-11, 2003.

All teams and offices participated in this week's Cassini monthly management review.

A Delivery Coordination Meeting was held for the Cassini Information Management System (CIMS).

The Mission Planning forum discussed the scope of activities to be performed in C40. C40 will contain the third Gravitational Wave Experiment and all remaining calibration and checkout activities before approach science.

ULO presented the CIMS 3.0 baseline, and possible future work, at the Cassini Design Team meeting. The design team accepted the baseline and proposed future work.

System Engineering will lead an effort to simplify and unify the directory structures on development, operations, and Science Operations and Planning Computer environments where software is installed.

An Associated Press article appearing on the web it reported that the winds of Saturn appear to be slowing dramatically just as NASA's Cassini spacecraft approaches the ringed gas planet. The Cassini spacecraft is due to arrive July 2004 for a 4 year orbital mission, and may provide more direct measurements to help explain the mystery of the diminishing winds. For more information go to: http://story.news.yahoo.com/news?tmpl=story&cid=624&ncid=624&e=2&u=/ap/20030616/ap_on_sc/exp_saturn_winds

Additional information about Cassini-Huygens is online at http://saturn.jpl.nasa.gov.

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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