Cassini Significant Events for 2/24/05 - 03/02/05

March 4, 2005

(Source: Jet Propulsion Laboratory)

Cassini Significant Events
for 02/24/05 - 03/02/05

The most recent spacecraft telemetry was acquired today from the Goldstone
tracking station. 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 .

Activities this week:

This week we executed Orbital Trim Maneuver #16, wrapped up the S08
background sequence, and started S09.

Science this week included Imaging Science Subsystem (ISS) continued
acquisition of movies of Saturn's southern hemisphere, the Composite and
Infrared Spectrometer (CIRS) collection of Mid-IR maps showing the
temperature of Saturn's troposphere and tropopause, a CIRS stay-light
calibration, and the suite of Magnetospheric and Plasma Science instruments
continued their simultaneous low-rate magnetospheric surveys.

Thursday, February 24:

Uplink Operations completed uplinking the remaining Instrument Expanded
Block files for S09.

The Radio and Plasma Wave Science (RPWS) team made its first Planetary Data
System (PDS) archive submission containing data from the 1999 Earth flyby.
After completion of a brief PDS validation, this dataset will be available
to the public through the PDS Plasma Physics Interactions Node.

Today's Astronomy Picture of the Day is an image of Saturn's moon Enceladus.
You can access "Ski Enceladus" at This is the 6th Cassini APOD
this month!

Tonight and tomorrow night the Cassini Spacecraft Operations Office Manager
will give JPL Von Karman Lectures on the Cassini Mission to Saturn. In
conjunction, the Saturn Observation Campaign will provide telescopes and
Saturn views at JPL for the Thursday night talk and in Pasadena for the
Friday night talk.
UPDATE: 400 people stopped for a look at Saturn and Titan, and many also saw
Mimas, Enceladus, Iapetus, Dione, Rhea and Tethys. About 100 people showed
up on Friday.

Friday, February 25:

Today the S09 background sequence was uplinked to the spacecraft. The
sequence is ready and waiting for activation on Saturday night. Along with
the sequence and Instrument Expanded Block files, commands to move the
Cassini Plasma Spectrometer (CAPS) actuator, update the CAPS Electron
Spectrometer high voltage step to 47, and perform an ACS reaction wheel bias
were also uplinked.

Deep Space Mission Systems delivery of D33 was accepted at a delivery review
today and was declared operational. Significant upgrades to both uplink and
downlink software were included for support of ISS and the Visual and
Infrared Mapping Spectrometer.

ISS has completed its analysis of the Integrated Test Laboratory run of ISS
flight software version 1.4. All data were as expected and no issues were
found. This test sequence will be executed in-flight in June for final
validation of the updated software.

ISS Support Imaging personnel received a new version of the ISS Science
Team's Pre-commanding Tool. This version has been installed for testing and

Another Astronomy Picture of the Day - this time "Saturn's Dragon Storm."

Saturday, February 26:

The final activity in S08 was a reaction wheel bias and desaturation. S09
began execution at 5:46 PM Pacific time. S09 runs for 41 days ending on
April 8. Key events include six OTMs from 15 through 20, two targeted
flybys - Enceladus and Titan, ten non-targeted encounters - Helene, Atlas,
two of Tethys, Enceladus, Epimetheus, Mimas, Dione, and Rhea, 54 optical
navigation images will be acquired, and approximately 64.5 gigabits of data
will be downlinked.

Sunday, February 27:

RPWS performed a Periodic Instrument Maintenance beginning today and
completing on Monday.

Orbit #4 began today as Cassini passed through Saturn apoapse. Apoapse is
the farthest the spacecraft will pass by Saturn. A new orbit always begins
and ends with apoapse.

Monday, February 28:

Official Port 1 was completed as part of the Science Operations Plan Update
for tour sequence S12. The files were merged and the resulting files made
available for review.

Today the Cassini Project Science Group began a weeklong series of
presentations and discussions.

Tuesday, March 1:

OTM-15 was successfully completed on the spacecraft this evening. This
apoapsis maneuver places the spacecraft on the proper trajectory for the
March 9, 500 km targeted flyby of Enceladus.

The main engine burn began at 9:59 p.m. PST. A "quick look" immediately
after the maneuver showed the burn duration was 40.1 sec long, giving a
delta-V of 6.2 m/s.

ACS reported the burn termination was a "nominal complete" with an
accelerometer cutoff. Navigation reported receiving ranging points before
and after the maneuver. Propulsion indicated the burn was nominal. Tank
pressures, temperatures, etc, were nominal. Thermal indicated performance
was nominal and temperatures were recovering as expected. Power margin
throughout the maneuver was nominal. There was no unexpected CDS or Fault
Protection activity.

Wednesday, March 2:

The Navigation team released a reconstructed Cassini trajectory file
covering the period from December 1, 2004 through January 15 of this year.
This file contains the spacecraft, probe, planetary, and satellite
ephemeredes and is for use for tour analysis for the period of the file.

Wrap up:

That's it for this week.

This week there were various articles on Cassini discussing new discoveries
of wandering and rubble-pile moons, new and clumpy Saturn rings and
ringlets, splintering storms, rainbows on Titan, images of Saturn's
radiation belt, and much more. Be sure to check out the Cassini web site for the latest press releases and images.

The Cassini-Huygens mission is a cooperative project of NASA, the European
Space Agency and the Italian Space 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.