Cassini Significant Events
for 10/12/06 - 10/18/06
The most recent spacecraft telemetry was acquired Wednesday, October 18,
from the Madrid 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 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, October 13 (DOY 286):
Sunday will be the 9th anniversary of the launch of Cassini and the Huygens
probe on October 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, October 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/multimedia/images/image-details.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 October 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, October 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 October 20,
with execution beginning on Sunday, October 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, October 17. This is
the apoapsis maneuver setting up for the Titan 20 encounter on October 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, October 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.
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.
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