From: Jet Propulsion Laboratory
Posted: Saturday, April 17, 2010
The most recent spacecraft telemetry was acquired on April 13th from the Deep Space Network tracking complex at Canberra, Australia. 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" page at: http://saturn.jpl.nasa.gov/mission/presentposition/
Wednesday, April 7 (DOY 097)
On April 7, Cassini encountered Dione at an altitude of 503 km and a speed of 8.4 km/s. Closest approach occurred at 2010-097 05:16:11 SCET, latitude zero deg. The Composite Infrared Spectrometer (CIRS), in control of spacecraft pointing, turned Cassini to Dione and began a dark side map of the satellite at a phase angle of ~165 degrees. The Ultraviolet Imaging Spectrograph (UVIS) mapped Dione's surface albedo in ultraviolet.
Imaging Science (ISS) acquired data for a 21-panel mosaic and then performed a sit-and-stare observation. At closest-approach, the Cassini Plasma Spectrometer (CAPS) took over pointing to observe the interaction between Dione and Saturn's magnetosphere with most of the other instruments riding along. Where possible, other instruments imaged the satellite in parallel with prime observations. Just prior to and after the flyby, the Optical Remote Sensing (ORS) instruments performed observations of the plumes of Enceladus. For more information on this flyby link to: http://saturn.jpl.nasa.gov/mission/flybys/dione20100407/ Another excellent release giving details of this flyby may be found at: http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20100402/
In addition to the Dione flyby, non-targeted flybys of Calypso, Epimetheus, Janus, Mimas, and Tethys occurred today.
Uplink Operations and Spacecraft Operations uplinked Ion and Neutral Mass Spectrometer Instrument Expanded Block files to the spacecraft today along with a program to clear the spacecraft error logs, repair portions of the Command & Data Subsystem library, perform a memory readout of the results, and set the priority playback list.
Friday, April 9 (DOY 099)
Science observations this week included UVIS observing the star Beta CMa being occulted by Saturn. The Visual and Infrared Mapping Spectrometer observed the E and G rings at 60-degree phase angle. ISS observed various satellites with the narrow angle camera as part of an ongoing satellite orbit campaign, performed observations as part of the Titan cloud monitoring campaign, and imaged the transit of Prometheus across Rhea, Dione across Titan, and Epimetheus across Janus. CAPS led co-rotation pointing for a Magnetosphere and Plasma Science (MAPS) instrument campaign to observe dawn-side magnetospheric boundaries at a variety of radial distances. The MAPS instruments also performed observations as part of the solar wind aurora campaign to study the auroral magnetosphere and the Saturn kilometric radiation source regions. The Magnetometer performed a calibration by rolling about the X-axis.
Saturday, April 10 (DOY 100)
Orbit Trim Maneuver (OTM) #242 was performed today. This was the cleanup maneuver from the Titan 67 / Dione 2 flybys on April 5 and 6. The main engine burn began at 5:30 PM PDT. Telemetry immediately after the maneuver showed a burn duration of 52.69 seconds, giving a delta-V of 9.037 m/s. All subsystems reported nominal performance after the maneuver.
Monday, April 12 (DOY 102)
The Science Forum for S63 was held today. Topics included an overview of the science planned for this sequence followed by highlights, unique activities, and highest priority observations as described by the Target Working Team (TWT) and Orbiter Science Team (OST) leads.
A news note entitled "Cassini Finishes Saturnian Doubleheader" discussed the completion of Cassini's special double flyby of Titan and Dione. The spacecraft beamed back stunning raw images of fractured terrain and craters big and small on Dione, a moon that had only been visited once before by Cassini. For the full details link to: http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20100408/
Tuesday, April 13 (DOY 103)
Science Planning and Uplink Operations hosted a kick-off meeting today for the handoff of the S61 background sequence product from the Science Operations Plan process (SOP) to the final process in sequence development, the Science and Sequence Update Process (SSUP). SSUP will last for approximately 10 weeks with S61 beginning execution on June 25. News Release Apr. 14: The project announced that Cassini has captured images of lightning on Saturn. The images have allowed scientists to create the first movie showing lightning flashing on another planet. For the full release go to: http://saturn.jpl.nasa.gov/news/newsreleases/newsrelease20100414/ .
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