Cassini Significant Events 07/03/07 - 07/10/07

July 12, 2007

(Source: Cassini Project)

The most recent spacecraft telemetry was acquired on Tuesday, July 10, from the Goldstone tracking complex. The Cassini spacecraft is in an excellent state of health and all subsystems are operating normally. Information on the present position and speed of the Cassini spacecraft may be found on the "Present Position" web page located at

Tuesday, July 3 (DOY 184):

Orbit Trim Maneuver (OTM) #119 was performed today. This is the cleanup maneuver from the Titan 33 encounter on June 29. The reaction control subsystem burn began at 2:45 AM PST. Telemetry immediately after the maneuver showed the burn duration was 13.88 seconds, giving a delta-V of 0.024 m/s. All subsystems reported nominal performance after the maneuver.

A delivery coordination meeting was held today for version 3.3.3 of the Cassini Information Management System (CIMS). This release supports a new resource check to validate prime SSR during an observation and downlink pass, and data volume analysis and management for high value science dual playback.

Wednesday, July 4 (DOY 185):

The JPL Public Information Office released the following over the July 4 holiday:
From data obtained during a flyby in September of 2005, Cassini obtained surface details of Saturn's moon Hyperion, including cup-like craters filled with hydrocarbons that may indicate more widespread presence in our solar system of basic chemicals necessary for life. Water and carbon dioxide ices were found as well as dark material that fits the spectral profile of hydrocarbons. A paper appearing in the July 5 issue of Nature reports details of Hyperion's surface craters and composition observed during this flyby, including keys to understanding the moon's origin and evolution over 4.5 billion years. This is the first time scientists were able to map the surface material on Hyperion. For the complete article link to:

Thursday, July 5 (DOY 186):

The ninth of fourteen science archive deliveries for the prime mission was completed on July 1 and is now available through the Planetary Data System (PDS). This delivery is comprised of Cassini science data obtained from July through September, 2006. Also, the first delivery of Cosmic Dust Analyzer (CDA)- High Rate Detector (HRD) data was delivered to the PDS Small Bodies Node, and is currently being verified. It is expected to be accessible by the public within the next two months.

The last delivery of Huygens data, Descent Imager Spectral Radiometer (DISR) data, is now available at the PDS Atmospheres node. The link for this node is:

Science this week was dedicated to apoapsis science and calibrations. The Ultraviolet Imaging Spectrograph (UVIS) observed the Saturn magnetosphere, the Magnetometer Subsystem (MAG) performed a calibration roll, the Visual and Infrared Mapping Spectrometer (VIMS) performed a stellar calibration, and also obtained an edge-on mosaic of the entire ring system from near apoapsis.

Friday, July 6 (DOY 187):

The Spacecraft Office reported the execution of an AACS backup gyro calibration. The calibration of Gyro B is divided into three parts beginning on Friday and ending in the early evening on Saturday. This is the last calibration necessary to complete parameter sets for the AACS flight software update version A8.7.6, currently on track for uplink to the spacecraft in January of 2008.

Monday, July 9 (DOY 190):

The Science Operations Plan Update process for S35 kicked off today. The preliminary input port for the process occurs on July 24, and the process will complete on August 17.

OTM-120, the apoapsis maneuver scheduled for July 8, 2007, has been deleted. The delta-V cost of deletion was small, about 40 mm/sec. The deletion eased workload during the weekend following July 4 and improved orbit determination accuracy leading to OTM-121 set to execute on July 15.

Over the weekend, the sequence leads for S32 began the uplink of files in support of that sequence. Twelve Instrument Expanded Block files were sent and confirmed on-board. Today the final sequence approval meeting was held along with a kick off meeting for a Radio Science (RSS) Live Update Block and a VIMS, Composite Infrared Spectrometer (CIRS), UVIS, and Imaging Science Subsystem (ISS) Live Inertial Vector Propagator (IVP) update for Hyperion and Helene. S32 will begin execution on Friday, July 13. UPDATE: At the Go/No go meeting on Tuesday it was agreed there was no need for a Live IVP update for Helene and Hyperion on DOY 201. RSS is still in need of its Live Update Block, so the building, analysis and approval of that file will continue.

On Thursday, files were uplinked for an on-board test of CDA flight software (FSW) version 10.4. The test runs for about 2.5 days, concluding on Thursday, July 12. At the end of the test, CDA will power cycle and reload the current FSW V10.0.

Tuesday, July 10 (DOY 191):

A presentation of the full DSN strawman plan for the proposed extended mission was given today at the Mission Planning Forum. This plan represents the first cut at what Cassini plans to request for DSN coverage for an extended mission. Touched upon were a wide range of "interesting" time periods involving all science disciplines, spacecraft issues, and navigation. Representatives from all science Target Working Teams, Orbiter Science Teams, the Spacecraft Office, Science Planning, and Navigation attended along with other interested parties from the project.