Cassini Significant Event Report

For Week Ending 09/17/04

The most recent spacecraft telemetry was acquired from the Madrid tracking station on Wednesday, September 15. 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 .

The final activities in tour sequence S03 included a Reaction Wheel Assembly (RWA) bias, uplink of the S04 background sequence and remaining Instrument Expanded Block (IEB) files, and uplink of three mini-sequences; RSP heater commands for probe activities, Ion and Neutral Mass Spectrometer (INMS) mini-sequence for flight software checkout, and the S04 Probe Checkout F15.

S04 began execution on Sunday, September 12. Initial on-board activities included loading of the IEBs and execution of the INMS flight software checkout. The key activity for this week was Probe Checkout #15. The checkout performed as expected which will allow the Probe battery depassivation activity scheduled for this weekend to proceed.

S04 continues many instrument observation campaigns from the S03 sequence. This includes a near-global Saturn atmospheric campaign, which observes wave propagation, spot merges, and eruption and evolution of convective storms. Ultraviolet imaging is also being used to examine polar hazes and to look for possible lightning on the night side of Saturn. Optical Navigation (OPNAV) images have recently been taken twice a day to refine Cassini's trajectory and improve knowledge of the satellites' orbits.

In the last week, 1421 Imaging Subsystem (ISS) images arrived along with 88 Visual and Infrared Mapping Spectrometer (VIMS) cubes. Since Approach Science began in January of this year, 20910 ISS images and 5239 VIMS cubes have been returned.

A preliminary port 1 delivery was made this week for the Science Operations Plan (SOP) Implementation process for tour sequences S37/S38, and the preliminary port delivery was made as part of the S07 SOP Update process. The team files have been merged for both deliveries and a report published identifying any issues.

An assessment meeting to scope out the proposed Aftermarket changes for S10 was held.

Sequence development continued for S05 this week with IEB files processed and published to the program file repository. An Integrated Test Laboratory (ITL) procedure walk-through for the Ta-Radar test was held. The test was designed to verify ACS and other commands needed for the Radar observations on October 26 during the Titan flyby, and verify that Radar data will be correctly obtained.

A kick-off meeting, Science Allocation Panel meeting, and a waiver request disposition meeting for the S06 Science and Sequence Update Process were held last week. A full merge of sequence products has been performed and a subsequence generation integrated product produced.

Cassini Information Management System (CIMS) developers discussed and demonstrated the new features delivered in CIMS 3.2 that are of interest to the Instrument Teams at an ad hoc Tour Process meeting this week.

An engineering delivery of Navigation software version T1.5 was made internally to the NAV team. The operational version will be delivered later in September.

All teams and offices supported this week's Cassini Monthly Management Review.

The Saturn Observation Campaign welcomed new members from New Mexico, Alaska and Ireland this week. There are now 354 members, who present year-round worldwide Cassini outreach and observing programs. Applications for membership, and a worldwide map can be found at:

Reading, Writing and Rings, Cassini Education's K-4 Literacy Program was recently selected as one of the top four educational programs by NASA. This means special training sessions will be offered for NASA Education Center Personnel, NASA-wide. The material can be downloaded from:

For the most recent Cassini information, press releases, and images, go to .