Cassini Significant Events for 10/05/06 - 10/11/06 The most recent spacecraft telemetry was acquired Wednesday, October 11, from the Goldstone 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 http://saturn.jpl.nasa.gov/operations/present-position.cfm . Thursday, October 5 (DOY 278): An Integrated Test Laboratory (ITL) test for the Titan 20 flyby sequence was completed today. The test was designed to validate a sequence to obtain accelerometer data during the T20 flyby. A modification to the telemetry schedule was needed to collect the data every 8 seconds. T20 will occur during the execution of S25. A new image of Saturn demonstrates a technique that creates a 'Chinese lantern' effect, showing Saturn's deep clouds silhouetted against the planet's warm, glowing interior. Seen this way, Saturn's interior shows surprising activity underneath the overlying haze, with a great variety of cloud shapes and sizes. For more information go to: http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=694 A slide show featuring colorful images of Saturn and Titan is available at: http://www.jpl.nasa.gov/multimedia/slideshows/cassini-200609/ Friday, October 6 (DOY 279): Orbit Trim Maneuver (OTM) #76 was performed on Friday, October 6. This is the approach maneuver setting up for the Titan 19 encounter on October 9. The reaction control subsystem burn began at 10:45 AM PDT. The playback data showed the burn duration was 26.5 seconds, imparting a delta-V of approximately 35.9 mm/s. All subsystems reported nominal performance after the maneuver. Monday, October 9 (DOY 282): On October 9, Cassini flew by Titan at 980km above the surface at a latitude of 61 degrees. Closest approach occurred near 2006-282T17:30:06. The RADAR instrument performed extensive high-resolution synthetic aperture radar imaging of the northern region where methane lakes were previously discovered. All the data from this flyby has been received on the ground and analysis has begun. Thruster duty cycle firing for the event was at 27.5%. Tuesday, October 10 (DOY 283): The main engine (ME) cover was closed today for dust hazard avoidance on October 12. The cover will be reopened prior to the execution of OTM-77. This is the 31st time the cover has been cycled since launch. The next planned closing will occur in June of 2007. Wednesday, October 11 (DOY 284): The S27 Science Operations Plan Update Project Briefing and waiver approval meeting was held today. The final development process will begin on Monday, October 16. Routine files to clear the CDS table entry and perform a memory read-out were uplinked to the spacecraft today following the Solid State Power Switch (SSPS) trip on October 3. This was the last activity related to the unexpected state change of the SSPS for the Stellar Reference Unit-A decontamination heater. Program Management made the decision today to cancel OTM-77. If executed, OTM-77 would have a magnitude of 0.16 m/s. Cancellation increases the magnitude of OTM-78 from about 0.25 m/s to about 0.85 m/s and changes it from a reaction control subsystem to a main engine maneuver. The overall cost of OTM-77 cancellation is about 0.47 m/s. Given this modest delta V increase and the reduction in both risk to the spacecraft and off-shift work, the decision was easy to come to. Media Relations supported several Cassini press briefings at the Division of Planetary Sciences (DPS) of the American Astronomical Society meeting this week in Pasadena, California. One news release and two image advisories were released in conjunction with this meeting. At the "Saturn" briefing today at the DPS the news was "Cassini Image Shows Saturn Draped in a String of Pearls http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=696 At the "Rings" briefing that same day: Saturn's Rings Show Evidence of a Modern-day Collision http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=697 and NASA Finds Saturn's Moons May Be Creating New Rings http://saturn.jpl.nasa.gov/news/press-release-details.cfm?newsID=698 In conjunction with the Titan briefing on Thursday, October 12, it is expected that two new RADAR images will be released on the web site. We will have the links for you in the Significant Events report next week. Wrap up: Check out the Cassini web site at http://saturn.jpl.nasa.gov for the latest press releases and images. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Spsce 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.
