Cassini Significant Events 10/12/06 - 10/18/06

October 20, 2006

(Source: Cassini Project)


The most recent spacecraft telemetry was acquired on Wednesday, Oct. 18, from the Madrid 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 at
http://saturn.jpl.nasa.gov/operations/present-position.cfm .

Thursday, Oct. 12 (DOY 285):

A Visual and Infrared Mapping Spectrometer false-color mosaic of the "red lantern" glow on Saturn was Astronomy Picture of the day today.

The Science Operations Plan Update process for S28 kicked off today. 

Friday, Oct. 13 (DOY 286):

Sunday will be the 9th anniversary of the launch of Cassini and the Huygens probe on Oct. 15,1997.

Cassini outreach has been active supporting the planetary education of about 200 4-8th graders each day at the 38th annual Division of Planetary Sciences (DPS) of the American Astronomical Society meeting, held this week in Pasadena. One of the students' favorite activities was to listen to the sounds of Saturn. There was also a lot of interest in the solar system display in which Cassini images were prominently displayed.

Monday, Oct. 16 (DOY 289):

An image of Saturn in eclipse with the rings highlighted as never before is Astronomy Picture of the Day today. You can find the image at: http://saturn.jpl.nasa.gov/photos/imagedetails/index.cfm?imageId=2315

The Titan Atmosphere Model Working Group (TAMWG) met at JPL to review the results of the Titan 19 (T19) flyby and to discuss future flyby safe altitudes. The T19 atmospheric density was somewhat less than predicted but consistent with recent flybys. Future flybys were considered to be at acceptable safe altitudes with the possible exception of T32. T32 is estimated to have a duty cycle of 70-80%, varying somewhat depending on whether the pass is used for the Ion and Neutral Mass Spectrometer or a solar occultation. The Navigation team will investigate whether raising the altitude by 25 km will adversely impact the tour. The next TAMWG will be held via telecon on Oct. 30 to discuss the results from the T20 flyby.

In University College, Dublin, a Cassini Magnetometer team member from Imperial College in London gave a talk on the Cassini Huygens Mission, presented by The Irish Astronomical Society in conjunction with the UCD Student Union. A movie of the Huygens probe landing on Titan was included and played to the audience of 50 Astronomy & Space Science students, post graduates from the Space Science Research Group, amateur astronomers, and members of the public. Handouts of Cassini outreach DVDs, posters and bookmarks were well appreciated by everyone attending.

The Integrated Test Laboratory concluded a test of RADAR pointing for the upcoming Titan 21 flyby. The time period for the test included the RADAR instrument warm up, instrument expanded block load, and transitions from reaction wheels to the reaction control subsystem, or thrusters, and back to reaction wheel control.

Tuesday, Oct. 17 (DOY 290):

The final sequence approval meeting for S25 was held today. The uplink of 15 instrument expanded block files began yesterday and will conclude tomorrow. The background sequence will be transmitted to the spacecraft on Oct. 20, with execution beginning on Sunday, Oct. 22.

The final development process for S27 began today. Initial subsequence files have been stripped and sent to all teams participating in this sequence. 

Orbit Trim Maneuver (OTM) #78 was performed on Tuesday, Oct. 17. This is the apoapsis maneuver setting up for the Titan 20 encounter on Oct. 25. The main engine burn began at 10:00 AM PDT. The playback data showed the burn duration was 5.2 seconds, imparting a delta-V of approximately 0.85 m/s. All subsystems reported nominal performance after the maneuver.


Wednesday, Oct. 18 (DOY 291):

Science observations this week started off near periapse with the Cosmic Dust Analyzer (CDA) controlling the spacecraft orientation to take advantage of Cassini's crossing of the Dione orbit. The Composite Infrared Spectrometer (CIRS) performed radial scans of the main rings to obtain thermal measurements while the Ultraviolet Imaging Spectrometer (UVIS) executed UV spectral mapping of the rings. Still near periapse, the Magnetospheric Imaging Instrument (MIMI) and other Magnetospheric and Plasma Science (MAPS) instruments studied the dynamics of the inner magnetosphere.

More than once this week, the Visual and Infrared Mapping Spectrometer (VIMS) and the Imaging Science Subsystem (ISS) stared at the F ring and observed continuously to create a movie and build up a 360 deg azimuthal map of the F ring. CIRS and UVIS also joined in to obtain data in a wide range of wavelengths.

The Imaging Science Subsystem (ISS) performed a continuous azimuthal scan of the rings with particular attention paid to selected ring features. Afterward, UVIS scanned the region around Enceladus to map volatiles and to see the connection with that satellite's plumes. A day later, ISS continued its ring observations this time making movies in search of ring spokes.

The week ended with CIRS obtaining data on Saturn's upper troposphere and tropopause temperatures with a spatial resolution of about two degrees of latitude and longitude.