Cassini Significant Events for 04/18/07 - 04/24/07 The most recent spacecraft telemetry was acquired on Tuesday, April 24, 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 http://saturn.jpl.nasa.gov/operations/present-position.cfm. Wednesday, April 18 (DOY 108): Orbit Trim Maneuver (OTM) #105 was performed today. This is the apoapsis maneuver setting up for the Titan 29 encounter on April 26. The main engine burn began at 9:45 PM PST. Telemetry immediately after the maneuver showed the burn duration was 21.9 seconds, giving a delta-V of 3.51 m/s. All subsystems reported nominal performance after the maneuver. Friday, April 20 (DOY 110): An encounter strategy meeting was held today to cover the period between April 26 and May 12, Titan flybys T29 and T30, and maneuvers 107-109. Monday, April 23 (DOY 113): Orbit Trim Maneuver (OTM) #106 was performed today. This is the approach maneuver setting up for the Titan 29 encounter on April 26. The reaction control subsystem (RCS) burn began at 9:30 PM PST. Telemetry immediately after the maneuver showed the burn duration was 9.0 seconds, giving a delta-V of 0.017 m/s. All subsystems reported nominal performance after the maneuver. This was the first OTM where the team adjusted the targeted time of arrival in order to make the OTM large enough to perform. As a policy, we had set the minimum delta-V limit for RCS burns at about 10 mm/sec. Without the arrival time adjustment, this OTM was around 8 mm/sec., which is below the minimum limit. The team was further constrained in that this OTM was not a candidate for cancellation, as the downstream delta-V cost of more than 2 m/sec was too high. This OTM was also particularly challenging as the team tried to find a design that minimized low-rpm regions for the reaction wheels. The Science Operations Plan update process for the S33 sequence kicked off today. The process will run for about five weeks and then will be handed off to the sequence leads for final development. Tuesday, April 24 (DOY 114): Today there were non-targeted flybys of Dione and Telesto. Although there were no observations planned for Telesto, the Imaging Science Subsystem acquired a two-by-two narrow angle camera mosaic of Dione, referred to as a regional map. The Cassini-Huygens Analysis and Results of the Mission (CHARM) teleconference for April was held today. The topic, "Enceladus: Cassini finds another Active World" was presented by a member of the Composite Infrared Spectrometer instrument team. The sequence for the second Radio and Plasma Wave Science Whistler search was uplinked to the spacecraft last Friday and executed on board today. The science teams are in the process of analyzing the data. 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 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. --- To unsubscribe from Cassini Spacecraft Updates, send a message to leave-cassini-@xxxxxxxxxxxxxxxxx --- Visit the JPL Cassini home page for more information about the Cassini Project: <http://saturn.jpl.nasa.gov/>
