Cassini Significant Event Report

For Week Ending 02/09/01

The most recent spacecraft telemetry was acquired from the Goldstone
tracking station on Tuesday, February 6. The Cassini spacecraft is in an
excellent state of health and is operating normally. The speed of the
spacecraft can be viewed on the
"Present Position"
web page.

The Probe Relay Test mini-sequence completed this week after executing the
remaining four tests. During the first 2 1/2 days of the test, the overall
Es/No, Delta F, and Pt (Bit transition probability) parameter space for the
two channels A and B was globally mapped. This included two configurations
for channel A (TCXO and RUSO). By analyzing the test data from one day to
the next, Huygens personnel were able to update their test plan for the
last 2 1/2 days enabling them to focus on further detailed regions of
interest identified from the global maps. Special test data for selected
cases were also identified and acquired. The overall data set is complete
and will take some time to analyze. The Huygens team expressed them
selves as "very delighted with the results" and offered thanks to the C24
team. More information may be found on the Huygens web site at:

After the completion of the Probe Relay Test, all instruments were
returned to active mode and the Radio Science Subsystem (RSS) Ka-band was
powered on. Commands were uplinked to continue the Radio and Plasma Wave
Science (RPWS) High Frequency Receiver (HFR) calibrations with the first
calibration occurring on Tuesday. Phase F Post Jupiter Activities resumed
beginning with two RPWS calibration activities, and Imaging Science
Subsystem (ISS) atmosphere observations. Additional activities included
CDS-A and CDS-B automatic SSR repairs, and clearing of the CDS error
logs. RPWS has taken a preliminary look at the data from the two
calibrations and everything looks fine so far.

The Cassini Instrument Operations (IO) Team and the Multi Mission Image
Processing Laboratory have produced and delivered 22,149 ISS images -
15,164 from the NAC and 6,985 from the Wide Angle Camera - and 4,823
Visual and Infrared Mapping Spectrometer (VIMS) cubes since Jupiter
encounter began.

The Spacecraft Operations Office held a Trajectory Correction Maneuver
(TCM)-17 strategy meeting this week. A main engine maneuver of
approximately 0.5 meters per second will be performed on February 28. The
primary purpose of the maneuver is to flush the oxidizer lines in the
bi-propellant system. Additionally, the maneuver will clean up the small
dispersions from the Jupiter flyby.

The Visual and Infrared Mapping Spectrometer (VIMS) team held a kick-off
meeting regarding the next round of flight software upgrades in
preparation for an in-flight test in C27.

The first of two C26 Science Planning Virtual Team (SPVT) product delivery
ports occurred on Monday. Science Planning has merged the instrument team
files and delivered them to AACS for running Kinematic Prediction Tool
/Inertial Vector Propagator (KPT/IVP) to perform an end-to-end pointing
check on the planned sequence.

The Project Science Group (PSG) Atmospheres Working Group (AWG) held a
telecon on Friday to work on science and orbit priorities for Tour. The
AWG is planning to hold weekly telecons over the next month to work Tour

A Delivery Coordination Meeting (DCM) was held for Mission Sequence
Subsystem (MSS) 4.7 delivery. Included was a patch for revision of a Main
Engine TCM block (METCM) for use in TCM-17.

Due to an increased number of requests over the last several weeks, System
Engineering has established a secure process to provide selected data
files from the Ops Project Software Library (PSL). A special area
controlled by the Configuration Management Engineer was established in AFS
space, allowing access for both Operations and Development networks.

Outreach has arranged with NASA CORE (Central Operation of Resources for
Educators) for a cost-recovery approach to distributing the Saturn
Educator Guide and Ways of Seeing CD-ROM. Cassini has supplied an initial
inventory of paper+CD-ROM copies. CORE will charge about $15 for these
materials, which will cover the cost of reproducing additional copies when
stock is depleted. The Saturn Educator Guide should stay in print
indefinitely with this approach. This represents a significant change
from the way published materials were handled in the past.

Outreach supported an AAUW career day, encouraging young women to pursue
careers in math and science. Cassini Jupiter flyby results were displayed
as part of the presentation.

Additional information about Cassini-Huygens is online at

Cassini will begin orbiting Saturn on July 1, 2004, and release its piggybacked Huygens probe about six months later for descent through the thick atmosphere of the moon Titan. Cassini-Huygens is a cooperative mission of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Office of Space Science, Washington, D.C.

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