Cassini Significant Event Report
For Week Ending 10/15/04
The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, October 13. 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://saturn.jpl.nasa.gov/operations/present-position.cfm .
On-board activities this week featured more varied Imaging Science Subsystem (ISS) observations than in previous weeks. In addition to movies of Saturn's rings, ISS performed a global color map of Iapetus, numerous observations of small satellites used for orbit determination, diffuse ring images, and Phoebe spectrophotometry. The Ultraviolet Imaging Spectrograph (UVIS) observed a stellar occultation interior to the B ring, which provided a high-resolution study of low optical depth regions.
Commands were approved and uplinked to the spacecraft this week to perform a live update for Iapetus, to turn off the Magnetospheric Imaging Instrument collimator, perform a Cosmic Dust Analyzer decontamination, and clear a global variable as part of the scheduled cleanup after the Attitude Control Subsystem (ACS) 8.7.1 flight software update and ACS flight computer swap. The Iapetus live update will execute on October 15, with closest approach on October 17. The S04 background sequence will then conclude on October 18.
The Spacecraft Operations Office ran a successful test of the Iapetus Live Inertial Vector Propagator (IVP) Update in the Integrated Test Laboratory (ITL) this week. The Flight Software Development System (FSDS) run also completed successfully. The ACS data from the test was reviewed and the files were verified for uplink. The pointing difference, during the Iapetus observation, between the FSDS C-Kernel and the Preliminary Sequence Integration and Validation (PSIV) 2 C-Kernel is 4.1 mrads. This is consistent with known ephemeris differences.
Science Planning has adjusted the schedule for Science Operations Plan (SOP) Implementation deliveries. The decision to modify the schedule was made in order to provide relief to the flight team as they support additional workload on the sequence development process as a result of last week's update of the Cassini reference trajectory. The only deliveries affected are for the last five sequences of the tour, S37 through S41. Preliminary port 2 for S37/S38 occurred on Friday of last week. The next delivery in support of SOP Implementation occurs on November 10.
The official port for the S08 SOP Update process occurred this week. The products were merged and delivered to the ACS team for end-to-end pointing validation.
The Titan Orbiter Science Team (TOST) and Satellite Orbiter Science Team (SOST) met to begin to re-integrate the Titan b, Titan 3, and Enceladus-4 flybys.
A Program internal science talk was given this week on recent ISS satellite discoveries. The presentation covered why instrument teams are interested in locating additional satellites, and the process used by the imaging team to find them.
S05 development had the tightest time constraints for modifications as a result of the release of the new reference trajectory. Last week the Sequence Team (ST) participated in a Sequence Change Request (SCR) approval meeting, command approval meeting for the Instrument Expanded Blocks to be uplinked to the spacecraft, and a final sequence approval meeting. In the last week, stripped subsequences were produced for use in the final FSIV merge, the merge was produced, products generated, and the Sequence of Events listing and Spaceflight Operations Schedule were generated. All this was done with no slip to the development schedule. An unexpected benefit of the new reference trajectory was the determination made by Science Planning that a live IVP update would not be necessary during S05, and thus, no ITL testing for those additional products would be required. The ST Lead has expressed much appreciation for all the hard work everyone put in to get this sequence out on time. S05 begins execution on Monday. October 18.
The Instrument Operations and Multi Mission Image Processing Laboratory have begun preparations to support the display of Titan-a ISS and VIMS data in near real-time. Interaction with Media Relations, JPL Audio/Visual, and Cassini Outreach are underway.
Mission Planning has released a Titan-a mission description. It is a brief, concise description of the Titan-a encounter events, including an estimated playback schedule for all instruments.
Delivery meetings were held this week for Maneuver Automation Software (MAS) 4.5, MDT V8.1, and MAPDF_GEN V8.1. In addition, a delivery coordination meeting was held to review RADAR build-5 ground software to be used to process the Ta data. The software has been tested and is ready for use.
The Mission Support & Services Office (MSSO) reported that last week the Flight Control Team supported 7 DSN passes, and uplinked 21 command files to the spacecraft.
Laminated images representing the Cassini-Huygens spacecraft during Saturn Orbit Insertion, a map of participating countries, and a selection of images will be included in a time capsule celebrating the 50th anniversary of the North Museum of Natural History and Science in Lancaster, PA. The capsule information will be displayed at the museum October 16-17. The selected images are on the Cassini Multimedia webpage.
Cassini Science Planning presented "Cassini-Huygens: The Real Lord of the Rings" during DePaul University's Space Sciences symposium for 150 k-12 educators, and again at the Swift Art Gallery, Los Angeles, for 40 members of the public.
Cassini Science Planning participated in "Journey Week" in Menominee, Michigan. During the week-long event, 1727 students and 72 teachers and adults from 8 different elementary, middle and high schools learned about the Cassini-Huygens mission and its exciting science results. This is the second year Cassini has participated in this program.
Science Planning and Huygens Probe Science & Engineering staff co-led a Solar System Ambassador Training class. This two-part training session focused on Titan and the Probe Mission. Over 50 members of the Ambassador network were trained on these materials.
For the most recent Cassini information, press releases, and images, go to http://saturn.jpl.nasa.gov .