Status Report

NASA Cassini Significant Events for 09/15/05 – 09/21/05

By SpaceRef Editor
September 26, 2005
Filed under , , ,
NASA Cassini Significant Events for 09/15/05 – 09/21/05

The most recent spacecraft telemetry was acquired Wednesday, September 21, 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, September 15 (DOY 258):

Yesterday Cassini passed apoapsis and the start of orbit #15. During this near-apoapsis period, the Magnetospheric and Plasma Science (MAPS) instruments will conduct a campaign to locate dawn-side magnetospheric boundaries and to observe plasma waves on the magnetospheric boundary at various radial distances, as well as continuing to survey the magnetosphere.

As was reported last week, science data was lost as the result of an improperly set flag preventing the spacecraft from writing to or reading from the A side of the solid state recorder (SSR). Commands were sent to the spacecraft today to re-enable SSR-A data recording. Telemetry confirmed that the files were received by the spacecraft. Now we wait for a normal data collection period and confirmation that all is well when that data is played back over tomorrow’s pass.

Friday, September 16 (DOY 259):

A press release with Radar images displaying an apparent shoreline on Titan has been issued. Hints are evident that this area was once wet, or currently has liquid present. For the full press release and access to the images go to:

The Spacecraft Operations Office (SCO) sent commands to the spacecraft to load Composite InfraRed Spectrometer (CIRS) flight software Version 4.0 into the non-default partitions of both SSRs. Checkout of this software is planned for mid October.

SCO reported that they were able to verify that SSR-A was the prime SSR during last night’s observation. This means that we are able to successfully command a swap to SSR-A to record data, and we have regained the use of both SSRs.

The flight team is gearing up for Orbit Trim Maneuver (OTM) #33. The preparation meeting was held last Wednesday, and a go ahead was given at an approval meeting today. The OTM files have been merged with the S14 background sequence and all have been released for use by the flight team. The maneuver will execute next Monday.

The official port occurred today for the S17 Science Operations Plan (SOP) Update process. The merged products are currently being run through the end-to-end pointing validation software by ACS. The Project Briefing and Waiver Disposition Meeting is scheduled for Wednesday, September 28. The SOP Update product is handed off to the sequence leads on Friday, September 30.

Monday, September 19 (DOY 262):

On Friday, a kickoff meeting was held for a Live Update to execute on DOY 266-269. A final orbit determination solution was released on Sunday, and today at the Go/No Go meeting it was decided that the update was still necessary but only for three Tethys vectors for DOY 266 and 267. When approved, the files will be uplinked to the spacecraft on Thursday, September 22.

A Hyperion and Tethys science preview meeting was held to present the instrument observation plans and science for the upcoming flybys.

Orbit trim maneuver #33 (OTM-33) was successfully completed today. This apoapsis maneuver sets up Cassini’s trajectory for the flyby of Hyperion on September 26. The main engine burn began at 11:00 am PST. A “quick look” immediately after the maneuver showed the burn duration was 176.3 sec, giving a delta-V of approximately 27.8 m/s. All subsystems reported nominal performance after completion of the burn.

At a Delivery Coordination Meeting SCO delivered version 11.1 of the Inertial Vector Propagator (IVP) software. This update was specifically released to fix issues related to the LIVE_IVP_UPDATE features. There are four outstanding test reports written against the released IVP software version V11.0 for problems encountered during Live IVP Update activities.

Tuesday, September 20 (DOY 263):

The OTM-34 preparation meeting was held today.

Cassini Outreach presented a poster on “Reading, Writing, and Rings” at the annual conference for the Astronomical Society of the Pacific meeting in Tucson, Arizona. The meeting was held September 14-16, 2005. Approximately 350 members of the astronomy education community attended.

As part of the science observation activities this week, the Ultraviolet Imaging Spectrograph (UVIS) performed a number of mosaics of Saturn’s inner magnetosphere. In addition, the Imaging Science Subsystem (ISS) took images of Mimas, Enceladus, Tethys, Dione, Rhea, and Iapetus to continue to map the various satellite longitudes at various phase angles. The other Optical Remote Sensing (ORS) instruments acquired data on these satellites as well.

Wednesday, September 21 (DOY 264):

The final sequence products for S15 have been posted to the Program file repository and are available for review. The sequence approval meeting will be held on Tuesday, September 27, with uplink of the background sequence and Instrument Expanded Blocks (IEB) beginning on October 3.

A Radar image of a shoreline on Titan was Astronomy Picture of the Day today.

An encounter strategy meeting was held for OTMs 35-37, and flybys Hyperion 1 and Dione 1.

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.

SpaceRef staff editor.