Cassini Significant Event Report

For Week Ending 10/01/04

The most recent spacecraft telemetry was acquired from the Madrid tracking station on Wednesday, September 29. 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 .

On-board activities this week included the continuation of Ultraviolet Imaging Spectrograph (UVIS) mosaics of Saturn's magnetosphere and solar wind measurements by the Magnetospheric and Plasma Science instruments. Cassini's Optical Navigation team took images twice a day to help refine Cassini's trajectory and improve knowledge of the satellites' orbits. The Imaging Science Subsystem (ISS) also obtained Saturn mosaics and recorded long-duration ring spoke movies.

On Friday of last week, a Software Requirements and Certification Review was held for version A8.7.1 of the Attitude Control Subsystem (ACS) flight software (FSW). After passing the review, the software was uplinked on Monday and Tuesday of this week by Spacecraft Operations Office Command and Data Subsystem engineers. Version A8.7.1 now resides on both solid-state recorders and non-default partitions 2 and 3. This and other activities are in preparation for the ACS Flight Computer (AFC) reload and checkout that will begin Saturday, October 2. Over this next weekend ACS engineers will reset the prime AFC and load the FSW. A limited checkout will then be performed to verify the implementation of the Probe Release sequence followed by a memory readout that will be used for the Titan A flyby later in October.

An ACS end-to-end pointing analysis of the products from official port#1 was delivered this week as part of the Science Operations Plan (SOP) Implementation process for tour sequences S37/S38. Teams are reviewing the report and adjusting input where necessary. In last week's Significant Event Report it was mistakenly reported that the process for S37/S38 had wrapped. S35/S36 held a wrap up meeting last week. Those products have now been archived and will be dusted off in July of 2007 when the Aftermarket process begins.

A Project Briefing and Waiver Disposition meeting was held as part of the SOP update process for S07. The handoff product for the following development process is being prepared.

The S09 SOP Update process began this week. This development process is 10 weeks long, twice as long as a normal SOP Update process. This sequence was one of the first four to go through SOP implementation back in May of 2002. Due to modifications in SOP implementation since then, S09-S12 require additional effort to produce the required input for the Science and Sequence Update Process (SSUP), the final step in sequence development before it is uplinked to the spacecraft.

As part of the SSUP process, Preliminary Sequence Integration and Validation Cycle 2 merged products were delivered for S05, merged Sub-Sequence Generation products were released for S06, and a Space Flight Operations Schedule was generated in preparation for the kick-off meeting for S07.

In the last week, 1205 ISS images were received along with 74 Visual and Infrared Mapping Spectrometer (VIMS) cubes. Since Approach Science began in January of this year, 24525 ISS images and 5410 VIMS cubes have been returned.

A delivery coordination meeting was held last week for version 2 of the Cassini Archive Tracking Tool. The Cassini Archive Tracking System is a web application tool that tracks required archive submissions into the Planetary Data System (PDS). It allows the project and PDS to accurately and efficiently report on archive submission status. It facilitates communication between teams, projects, and PDS. Version 1 was delivered in April of this year.

Cassini Outreach and Saturn Observation Campaign (SOC) members showed the lunar crater Cassini and Mount Huygens - both on the moon - to 117 members of the public at Monrovia Library Park, near Pasadena's Jet propulsion Laboratory this week. Cassini bookmarks, and NASA lunar lithographs and trading cards were passed out to all who stopped by. Several local teachers requested school visits including one high school teacher who teaches science writing to 11th and 12th graders. Saturn will not be visible in the early evening for public viewing until January 2005, when SOC members will be out in force showing the ringed planet and Titan to their communities. To find your nearest of the 362 SOC members, visit the website:

Cassini-Huygens made a guest appearance on the television show "Jack & Bobby" on Sunday September 26th. A spacecraft model, computer animation, and posters were used as set pieces and information on the Huygens mission as well as Cassini's journey to Saturn was included in the script. Jack & Bobby airs on the WB network on Sunday evenings.

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