Cassini Significant Events 10/04/11 – 10/11/11

The most recent spacecraft telemetry was acquired on Oct. 11 from the Deep Space Network tracking complex at Canberra, Australia. The Cassini spacecraft is in an excellent state of health and with the exception of the CAPS instrument being powered off, all subsystems are operating normally. Information on the present position and speed of the Cassini spacecraft may be found on the "Present Position" page at: http://saturn.jpl.nasa.gov/mission/presentposition/.

Wednesday, Oct. 5 (DOY 278)

On Oct. 4-5, JPL held a teacher professional development workshop in Jonesborough, Tennessee. Twenty-five teachers from Washington County, Sullivan County, and Kingsport City schools participated in the two-day workshop. Members of the Cassini Spacecraft Operations Office (SCO), Outreach, and Program staff led hands-on activities using "Our Solar System Through the Eyes of Scientists" and other Cassini educational products and programs.

In support of the S73 sequence development, the Radar Team agreed to an early delivery of Pointing Design Tool (PDT) designs for Titan encounters T-83 and T-84 so the Attitude and Articulation Control Subsystem (AACS) Team can assess whether or not there are any control authority issues for these upcoming relatively low altitude flybys on thrusters. Similar concerns for future low Titan flybys will need to be resolved as soon as possible, before integrated segments are due.

Thursday, Oct. 6 (DOY 279)

Cassini Outreach and SCO team members conducted classroom visits at David Crockett High School in Jonesborough, Tennessee and University School in Johnson City, Tennessee, today.

Preliminary Sequence Integration and Validation (PSIV) Spacecraft Activity Sequence File (SASF) products were due today as part of the S71 Sequence Implementation Process (SIP). The products will be merged and the Science Planning Assessment (of the) Merge (SPAM) is due on Monday, Oct. 10.

Friday, Oct. 7 (DOY 280)

A telemetry mode overlay real time command was executed today to avoid losing playback data due to the loss of 2 hours and 25 minutes of DSN tracking time as a consequence of a late tracking schedule change.

Orbit Trim Maneuver (OTM) #295, the Enceladus 15 (E-15) approach maneuver scheduled for Sunday, Oct. 9, was cancelled at the preliminary Navigation Review meeting today. There was no science impact or propellant usage cost resulting from the cancellation.

The spacecraft will pass through solar conjunction next week, with a minimum Sun Earth Probe (SEP) angle of 2.2 degrees on Thursday, Oct. 13, about 1.95 degrees off the solar limb.

OTM 296, the E-15 cleanup maneuver, is scheduled to execute on Oct. 20.

Saturday, Oct. 8 (DOY 281)

The Instrument Operations System/Multi Mission Image Processing Laboratory (IOS/MIPL) completed development of upcoming Cassini Delivery 40 (CAS D40). The delivery will proceed to Integration and Test, and is scheduled to become operational in December 2011.

Monday, Oct. 10 (DOY 283)

This week, while the spacecraft approached apoapsis, science activities included an eight hour calibration performed by the Magnetometer (MAG) while the spacecraft rolled about its X-axis. This was followed by a series of five 12-hour scans of Saturn’s inner magnetosphere by the Ultraviolet Imaging Spectrograph (UVIS), the Imaging Science Subsystem (ISS), and the Visual and Infrared Mapping Spectrometer (VIMS), with the primary objective of mapping neutral species such as oxygen. ISS performed two sets of astrometric observations of some of Saturn's small inner moons, and the week concluded with Cassini entering the solar conjunction period.

Tuesday, Oct. 11 (DOY 284)

Solar conjunction begins today and continues through Sunday, Oct. 16. The Sun-Earth-Spacecraft angle is less than 3 degrees during this time. Attitude control was switched from reaction wheels to thrusters to facilitate a possible redistribution of lubrication in the wheel bearings during this time.