Cassini Significant Events 12/08/05 - 12/14/05

December 16, 2005

(Source: Cassini Project)

Thursday, December 8 (DOY 342):

A member of the Cosmic Dust Analyzer (CDA) instrument team visiting JPL from the Max-Planck-Institut für Kernphysik in Heidelberg, Germany, gave a talk today on the latest CDA science results.

The decision was made today to cancel Orbit Trim Maneuver #45 (OTM) scheduled for Saturday, December 10. The Science Teams, Uplink Operations and Spacecraft Operations office had no objections to the cancellation. A Reaction Wheel Assembly (RWA) bias will be sent in place of the maneuver. Although the maneuver was part of events in S16, its cancellation affects the first S17 live update. A live update of the Telesto vector will be required at a minimum, and perhaps Enceladus as well.

This week the Magnetospheric and Plasma Science (MAPS) instruments investigated boundaries on the dawn-side of the magnetosphere, including the bow shock, magnetopause, and associated boundary layers. In addition, a Phoebe spectrophotometry campaign is underway, and the RADAR team performed a distant Titan longitude study.

Friday, December 9 (DOY 343):

At the kick off meeting for the S17 Live Inertial Vector Propagator (IVP) update for DOY 05-358, it was decided that the Enceladus and Telesto vectors would be updated, and the Saturn-Cassini vector and the Titan vector would not be updated. ACS will use the new rock ephemeris file to generate the updated vectors. The Go/No Go meeting scheduled for Monday, December 12, has been cancelled since it has already been determined that the update is needed.

Monday, December 12 (DOY 346):

The Aftermarket process for the S21 sequence began today. Teams were requested to submit all proposed science and engineering changes by last Thursday if they were to be considered for inclusion in the update process.

Mission Planning released an updated consumables report. The report documents hydrazine usage, main engine cover cycles, and status of other on board "consumables".

The project has settled on a set of encounter altitudes for the remaining Titan flybys in the tour. Mission Planning released a summary of this information to the flight team. Work is currently underway to update the reference trajectory, incorporating the new flyby altitudes and attempting to minimize the impact on science integration. A preliminary trajectory has been constructed and released for evaluation. Navigation is looking for a list of the Saturn periapsis time shifts that either a) make an observation no longer possible or b) require significant re-work. Another list that might be helpful is areas where a little tweak could save a lot of work. Status of this effort will be reported at the forthcoming Project Science Group meeting in January 2006.

Astronomy Magazine has released their picks for the Top 10 astronomy-related stories of 2005. "A year at Saturn - Iapetus bulge, Titan CH4 Lake, Enceladus tiger stripes and atmosphere" was rated number 6 of 10, and "Huygens lands on Titan" made number 1!

Members of the Outreach and Science Planning teams met with students at Shirley Elementary School in Reseda, CA. These students participated in the pilot program of "Scientist for a Day."

Tuesday, December 13 (DOY 347):

A close-up image of the many craters on Rhea's icy surface is Astronomy Picture of the Day today.

The final sequence development process for S19 kicked off today. The sequence leads released version A of the background sequence products along with stripped subsequence files for the teams to review.

Cassini Plasma Spectrometer, Visual and Infrared Mapping Spectrometer, Composite Infrared Spectrometer, Optical Navigation, and Ultraviolet Imaging Spectrograph instrument expanded block (IEB) files for S17 were uplinked to the spacecraft today along with an S16 ACS RWA bias. It was verified that all the SSR IEB loads have been properly received by the SSR. The RWA bias is resident and will execute on 05-351. Tomorrow the Imaging Science Subsystem IEB goes up along with the S17 background sequence.

Wednesday, December 14 (DOY 348):

A member of the RADAR instrument team gave a presentation to the flight team on some of the recent RADAR icy satellite scatterometry results.

The planet Saturn finally cleared the eastern horizon this month to the delight of stargazers everywhere. From now until mid-2006, it's Saturn time! Saturn, the Jewel of the Solar System [link to] is now visible low in the eastern sky after 8:00 p.m.
At 9 p.m. local time December 18, the bright waning gibbous moon appears close to the ringed planet. On this night Saturn can be seen as a pale golden planet below and to the right of the moon. If you miss it, don't worry, this celestial dance is visible every month, and you'll see the moon near Saturn again, but earlier and higher in the sky on January 14/15 and February 10/11.

A delivery coordination meeting was held for version 12a of the Command Database. This version is scheduled for use with Mission Sequence Subsystem D12 when it is delivered in May of 2006.

Wrap up:

The most recent spacecraft telemetry was acquired Wednesday, December 14, from the Goldstone tracking complex. The Cassini spacecraft is in an excellent state of health and all subsystems are operating normally. Check out the Cassini web site at for the latest press releases and images.