Cassini Significant Events -- for 11/10/05 - 11/16/05

November 18, 2005

(Source: Cassini Project)

Thursday, November 10 (DOY 314):

Cassini Outreach and a Saturn Observation campaign member presented a children's program at the Monrovia Public Library last week. While waiting for the rain to disperse outside, the children learned about Saturn by making their own "Layers of Saturn" books. This activity is the subject of Lesson 9 for grades 1 and 2 in Cassini's Reading, Writing and Rings literacy program. In addition, 'Reading, Writing, and Rings' was presented to 20 educators at Mesa Union School District in Somis, California, and 108 participants in the Collaborative After School Project in Los Angeles, California.

Friday, November 11 (DOY 315):

Members of the Imaging Science Subsystem (ISS) are supporting deviations from the nominal S19 uplink process. The science team has found that the exposures in S19 can't be properly determined until the S17 data is available. Because it arrives a few days after the deadline for S19 instrument expanded block files (IEB), the team must make special arrangements. The plan is to upload changes to exposures on some observations after the sequence is on-board and before the S19 triggers.

Saturday, November 12 (DOY 316):

The S16 background sequence began execution today at 10:15 AM Pacific time. The sequence runs for 34 days concluding on December 17. Activities during S16 include four Orbit Trim Maneuvers (OTM), numbers 42, 43, 44, and 45, one targeted flyby of Rhea over the Thanksgiving weekend, and two non-targeted flybys, one each of Enceladus and Helene. Sixteen optical navigation images will be taken, periodic spacecraft engineering maintenance will be performed, and 41 DSN tracks will be utilized.

Two live updates were identified for S16, Iapetus beginning on DOY 316 and Rhea on DOY 330. The DOY 316 update was cancelled on November 1. The Go/No Go meeting for the Rhea update is scheduled for Wednesday, November 23.

With the start of S16 and the third closest approach to Iapetus in the tour, the Optical Remote Sensing instruments will continue the Iapetus campaign begun in S15. ISS continues spectrophotometry, the Ultraviolet Imaging Spectrograph will measure UV albedo across various longitudes and phase angles, and the Composite Infrared Spectrometer (CIRS) will continue its Iapetus observations with high spectral resolution integration for composition. RADAR scatterometry and radiometry of Iapetus will also be obtained. The Magnetospheric and Plasma Science instruments continue to observe the dawn-side magnetospheric boundaries at a variety of radial distances, including the bow shock, magnetopause and associated boundary layers.

Uplink Operations sent commands to the spacecraft to perform a switch of CIRS flight software from version 3.0.1. to 4.0. Execution will occur on Tuesday.

Twenty-five years ago on November 12, 1980, the Voyager 1 spacecraft had its close encounter with Titan as it flew through the Saturnian system. Data returned from that mission showed Titan completely enveloped by haze that merges with a darker cloud layer over the North Pole. Voyager found that Titan had a substantial atmosphere.

Sunday, November 13 (DOY 317):

Orbit trim maneuver #42 (OTM-42) was performed today. This is an apoapsis maneuver setting up Cassini's flyby of Rhea on November 26. The main engine burn began at 7:16 am Pacific Time. Telemetry immediately after the maneuver showed the burn duration was 13.2 sec, giving a delta-V of approximately 2.1 m/s. All subsystems reported nominal performance after the OTM.

Monday, November 14 (DOY 318):

Every instrument team has submitted 100% of their archive data products that were due on October 1, 2005. In addition, the Planetary Data System (PDS) has accepted 100% of these products for most teams, and is in the process of reviewing the data for the rest. Instrument teams have already begun submitting some of the data products scheduled to be delivered on January 1, 2006.

Tuesday, November 15 (DOY 319):

An encounter strategy meeting was held today covering the period from November 26 through December 26. This includes the Rhea 1 and Titan 9 flybys and OTMs 44-46.

The tumble densities for Titan-25 through Titan-43 were presented at the Mission Planning Forum today. There are currently 21 low altitude Titan flybys scheduled between now and end of mission in 2008. The purpose of the meeting was to present the results of the work performed thus far by the Spacecraft team in determining tumbling and safe atmospheric densities for these flybys.

Wednesday, November 16 (DOY 320):

A Cassini tour science talk was given on the results of the Huygens Probe Doppler Wind experiment.

Wrap up:

The most recent spacecraft telemetry was acquired Wednesday, November 16, 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.