Cassini Significant Events
for 02/04/09 - 02/10/09

The most recent spacecraft telemetry was acquired on Feb. 10 from the
Deep Space Network tracking complex at Goldstone, California.  The
Cassini spacecraft is in an excellent state of health. 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.


Thursday, Feb. 5 (DOY 036):

Much of the science data obtained yesterday and today came from
Imaging Science's (ISS) campaign to study the formation of spokes in
the rings and to track Saturn's smallest moons.

A command approval meeting was held today for Instrument Expanded
Block (IEB) files for the Composite Infrared Spectrometer (CIRS),
Visual and Infrared Mapping Spectrometer (VIMS), ISS, Optical
Navigation, Cassini Plasma Spectrometer (CAPS), and Ultraviolet
Imaging Spectrograph (UVIS) to be sent to the spacecraft in support
of S48.  Uplink of these files will begin late in the evening on Feb.
10.  S48 begins execution on Feb. 17.  In addition to the IEBs,
approval was given for uplink of a program to perform maintenance,
clear the error logs, repair the CDS library, perform a memory read
out, and set the priority playback list.


Friday, Feb. 6 (DOY 037):

The last delivery occurred today for the Science Operations Plan
process for S50.  On Feb. 20 the files and all related documentation
will be bundled up and handed over to Uplink Operations for final
sequence development.


Saturday, Feb. 7 (DOY 038):

Cassini completed the targeted Titan 50 flyby on Feb. 7, passing the
moon at a distance of 960 kilometers above the surface, and at a
speed of 6.3 km/s. Closest approach occurred at about 2:06 AM PST at
a latitude of 33.7 degrees S.


TITAN-50 Science Highlights

Closest approach at T50 featured the Ion and Neutral Mass
Spectrometer (INMS) as the "prime" instrument, in control of exactly
where the spacecraft would be pointed for this flyby.  The
observation was designed to measure the boundary between the wake
side and the inner flank of the magnetospheric interaction region at
mid-southern latitudes. RADAR rode along with INMS at closest
approach. During the flyby, the instrument collected synthetic
aperture radar data over the mountain ranges southwest of Tsegihi,
and obtained altimetry measurements inbound and outbound.

For the Optical Remote Sensing instruments, CIRS focused on mapping
temperatures, trace hydrocarbons, nitriles and oxygen compounds in
Titan's stratosphere along with searching for weak isotopes and new
gas species. VIMS performed cloud mapping and observations of the
atmosphere at the limb.  UVIS obtained an image cube of Titan's
atmosphere at extreme ultraviolet and far ultraviolet wavelengths by
sweeping its slit across the disk. These cubes provide spectral and
spatial information on nitrogen emissions, H emission and absorption,
absorption by simple hydrocarbons, and the scattering properties of
haze aerosols. This is one of many such cubes gathered over the
course of the mission to provide latitude and seasonal coverage of
Titan's middle atmosphere and stratosphere.

For the Magnetosphere and Plasma Science suite of instruments, the
Magnetospheric Imaging Instrument (MIMI) measured energetic ion and
electron energy input to Titan's atmosphere. Because T50 was an
upstream flank-in flyby, the geometry was suitable for the
Magnetometer Subsystem (MAG) to study the magnetic pileup region
across the night side hemisphere. T50 also took place in Saturn's
near-noon sector where Titan could be found in the magnetosheath if
the solar wind pressure was high. This is an arrangement that is also
of interest to MAG.  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.

Monday, Feb. 9 (DOY 040):

Orbit Trim Maneuver (OTM) #182 was performed today.  This is the
cleanup maneuver from the Titan 50 encounter on Feb. 7.  The main
engine burn began at 3:15 AM PST. Telemetry immediately after the
maneuver showed the burn duration was 2.1 seconds, giving a delta-V
of 0.35 m/s. All subsystems reported nominal performance after the
maneuver.


Tuesday, Feb. 10 (DOY 041):

A kickoff meeting was held yesterday for a live update for Saturn and
Titan to occur over DOY 44-45.  By today, all the votes were in. With
no pointing errors above 0.43 mrad, the changes would be well below
the threshold necessary to drive this update process.  With the
concurrence of Science Planning and all participating instruments,
the update has been cancelled.

Visit the JPL Cassini home page for more information about the
Cassini Project: http://saturn.jpl.nasa.gov/>
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