From: Jet Propulsion Laboratory
Posted: Monday, January 18, 2010
The most recent spacecraft telemetry was acquired on Jan. 12 from the Deep Space Network tracking complex at Madrid, Spain. 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/operations/present-position.cfm .
Wednesday, Jan. 6 (DOY 006)
An encounter strategy meeting was held today to cover the period between Jan. 12 and Jan. 28, Titan flybys T65 and T66, and maneuvers 233-235.
The Cassini Scientist for a Day essay contest winners from the United Kingdom and Ireland were honored on December 16, 2009, at the Parliamentary Space Committee reception in the House of Commons, London, England. Lucy Hawking, daughter of Professor Stephen Hawking, and astronaut Richard Garroitt made presentations to the winners.
Thursday, Jan. 7 (DOY 007)
As part of regular maintenance, Spacecraft Operations reset the reaction wheel assembly revolution counter to zero. The commands were part of the background sequence rather than sent up in real time.
The Ion and Neutral Mass Spectrometer (INMS) has been successfully powered on after the Solid State Power Switch (SSPS) trip on Jan. 2. The instrument is currently in active science mode with correct data rate and science table running.
Friday, Jan. 8 (DOY 008)
Commanding today included the uplink of real time Automated Sequence Process commands for the Cosmic Dust Analyzer to change instrument sensitivity during the upcoming periapse period on Jan. 10, spacecraft commands to clear the SSPS trip count and confirm an onboard memory readout, the final step in cleanup after last week's trip, and Orbit Trim Maneuver (OTM) 232 was uplinked today, one pass earlier than scheduled.
As part of the S59 Science Operations Plan (SOP) process, participating teams submitted files for the third and final port of the process. S59 SOP concludes Jan. 22 when all files will be handed off to uplink operations for the final process in sequence development.
Saturday, Jan. 9 (DOY 009)
Orbit Trim Maneuver (OTM) #232 was performed today. This was the approach maneuver setting up for the Titan 65 encounter on Jan. 11. The Reaction Control Subsystem burn began at 12:45 PM PST. Telemetry immediately after the maneuver showed a burn duration of 28.38 seconds, giving a delta-V of 35.12 mm/s. All subsystems reported nominal performance after the maneuver.
The AACS secondary safe table was updated to 25 degrees on Jan. 10, for the Titan 65 flyby. It will be returned to 0 degrees on Jan. 13.
Monday, Jan. 11 (DOY 011):
The Cassini Radio Science Subsystem (RSS) performed a 6.5h gravity field experiment today to determine Saturn’s gravity field and infer constraints on its internal structure.
Non-targeted flybys of Pandora, Methone, Enceladus, and Calypso occurred today.
A feature story called “As the Crust Turns: Cassini Data Show Enceladus in Motion” highlighted a paper from Nature Geoscience that proposed a new model that explains the quirky heat behavior and intriguing surface of the moon’s south polar region. The paper described blobs of warm ice that periodically rise to Enceladus’ surface and churn the icy crust. For details, go to: http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20100111/
Tuesday, Jan. 12 (DOY 012)
Spacecraft Operations hosted the S62 Engineering Activities Review today.
On Jan. 12, Cassini flew by Titan at an altitude of 1,073 km and a speed of 5.9 km/sec. The latitude at closest approach was 82 degrees S. During Titan 65, RADAR obtained another view of Ontario Lacus, providing an opportunity to see evaporation at the methane and ethane lake near the south pole. In addition, this was the most southerly latitude pass in the mission, enabling INMS to sample deep into the southern atmosphere and measure possible seasonal changes.
This was the third of three opportunities for the Cassini Plasma Spectrometer to be prime during an extended encounter. Both inbound and outbound legs were good opportunities at a distance of less than 17 Titan radii at nominal upstream conditions. Comparison with T64 and T63 data will give important results on the structure of Titan's magnetic tail in the dusk sector.
RADAR rode along with INMS inbound and performed Synthetic Aperture RADAR (SAR) observations. SAR was also used outbound over Ontario Lacus. INMS was prime on the inbound leg of T65 and rode along with RADAR outbound. The ride-along with RADAR provided a look at the polar surface and the polar atmosphere in a single flyby. It also provided excellent temporal proximity to T64 for comparison of the north and south polar regions.
CIRS performed most of its observation types: surface temperature map, stratosphere map, and integrations for trace species and composition.
ISS rode along with CIRS to track clouds and continued to monitor clouds and their evolution for an extra day after the Titan encounter.
During this flyby, VIMS rode along with CIRS on the outbound leg where the phase angle was about 45 degrees. It provided a good opportunity to get a mosaic of the equatorial area between 160 and 270 longitude - corresponding to the western portion of Shangri-la and Adiri - the probe landing site - at a resolution of 25 to 30 km/pixel. VIMS also continued monitoring for mid-latitude clouds. On the inbound leg, VIMS looked at the terminator.
For the Magnetometer, the T65 flyby was almost identical to T64, but over Titan's south pole. In nominal upstream conditions, the instrument explored the south lobe of Titan's magnetic tail, very close to the moon.
The Magnetospheric Imaging Instrument observed energetic ion and electron energy input to Titan's atmosphere. Finally, the Radio and Plasma Wave Science instrument measured thermal plasmas in Titan's ionosphere and surrounding environment, searched for lightning in Titan's atmosphere, and investigated the interaction of Titan with Saturn's magnetosphere. For more information visit: http://saturn.jpl.nasa.gov/mission/flybys/titan20100112/
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