Cassini Significant Events for 07/06/06 - 07/12/06

Cassini Significant Events for 07/06/06 - 07/12/06

The most recent spacecraft telemetry was acquired Wednesday, July 12, from the Madrid tracking stations. 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 .

Thursday, July 06 (187):

A brief summary has been released from the executive session of last month’s Project Science Group (PSG) meeting. Two of the topics discussed were extended mission planning, and high-value data insurance. For extended mission, tour classes P, O, and Q were designated for further development. It is planned that a number of specific tours in these classes will be developed for the next PSG meeting in October of this year.

Regarding the protection of high-value science, the possibilities and effects of salvaging data recorded on the spacecraft but, through error or failure, not transmitted to or captured on the ground were discussed. Concerns about additional workload were voiced. Mission Planning took an action to explore and develop information on the several approaches possible and estimates of their impacts on available resources both within JPL and at the distributed operations sites. The results of this will also be presented at the next PSG meeting.

On Thursday, July 6, a 13.5 hour Ultraviolet Imaging Spectrograph (UVIS) observation of Saturn was performed. This is a slow scan of Saturn across Saturn’s visible hemisphere, at a high phase angle to form spectral images at a Saturn distance of two million kilometers. Near the end of the day, Optical Navigation (Opnav) images were obtained of Saturn’s moons against the background star field. These images help determine the spacecraft trajectory as well as the orbits of the satellites.

Friday, July 07 (DOY 188):

A final approval meeting was held today for the “h” version of the S22 background sequence. The sequence leads were in the process of polling participants for their “OK” to uplink when proceedings were interrupted by a fire drill! Leads received a number of approvals and a waiver comment via email after the drill was over. Update: The sequence was finally declared approved on Tuesday, July 11.

Monday, July 10 (DOY 191):

Mission Support and Services Office (MSSO) personnel periodically must upgrade components, operating systems, software, and whatever else is necessary in order for the Cassini ground system to remain current and to advance in capability. This is by no means a simple task. Recently new Telemetry, Tracking, Command & Data Management (TTC&DM) software was delivered to the Project. It then went through a rigorous user acceptance-testing program prior to acceptance of the delivery. MSSO must now coordinate with the flight team for upgrade to the individual workstations that run the software. All of the machines for Instrument Operations (IO) and about half of the machines for the Spacecraft Operations Office, Uplink Operations, and the ACEs have been upgraded. IO and MSSO are coordinating the upgrade of machines used by the scientists at the distributed operations sites. The first upgrade has been made to one of the machines used by UVIS. Others will follow along shortly.

Tuesday, July 11 (DOY 192):

Cassini reached apoapsis, the farthest point, in our 26th orbit of Saturn today. Almost all of the day was taken up by a Composite Infrared Spectrometer (CIRS) observation of Saturn. CIRS spent 21 hours taking mid-infrared images of Saturn’s upper troposphere, mapping it with high spatial resolution.

A kick-off meeting was held today as part of the final sequence development process for the S24 background sequence. Merged products from the Science Operations Plan update process were made available in the file repository along with stripped Spacecraft Activity Sequence Files for the participating teams to populate and return to the sequence leads.

A beautiful image of Rhea against Saturn’s crescent with an edge-on view of the rings is Astronomy Picture of the Day today.

Wednesday, July 12 (DOY 193):

The S22 SSR and instrument-direct instrument expanded block (IEB) loads were uplinked successfully on Tuesday and early Wednesday morning. The uplinks had all originally been scheduled for Tuesday. DSS-14 had been red just prior to the start of track but the DSN believed it would be available for Cassini to use. Unfortunately, a partial loss of the DSS-14 track did occur. The DSN operators worked valiantly to restore the antenna so only about 3 hours were lost before the antenna was recovered shortly before 192/19:50. There is always a backup pass scheduled when uplinking IEBs to cover just this sort of contingency, so Wednesday’s track beginning at 2:00 AM came in very handy. Uplink of the background sequence is scheduled for July 14 with a backup pass on July 15.

A delivery coordination meeting was held today for version 1.5.2 of the electronic command request form. This is a point delivery to accommodate a Spacecraft Operations Office (SCO) request to allow Maneuver Automation Software to generate requests for reaction wheel bias commands in the event of a maneuver cancellation.

An Encounter Strategy Meeting for the Titan 16 and Titan 17 flybys was held today. The meeting addressed mission, sequence, navigation, spacecraft, and instrument overviews and status for maneuvers 68-70, and the time period from July 22 through September 7.

Cassini Outreach presented “Cassini’s Halftime Highlights” to 60 enthusiasts at the Sonoma County Astronomical Society at Proctor Terrace Elementary School, Santa Rosa, CA. Cassini Outreach material was handed out to all attendees.

Wrap up:

Check out the Cassini web site at for the latest press releases and images.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Science Mission Directorate, Washington, D.C. JPL designed, developed and assembled the Cassini orbiter.