Cassini Update - December 19, 2003

Cassini Significant Events
for 12/11/03 - 12/17/03

The most recent spacecraft telemetry was acquired from the Madrid
tracking station on Monday, December 15. 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/operation...t-position.cfm .

On-board activities this week included execution of Probe pre-heating
checkout test #2, a Composite Infrared Spectrometer flight software
checkout, execution of the Ion and Neutral Mass Spectrometer recovery
mini-sequence, and a spacecraft Periodic Engineering Maintenance
activity.

Preliminary port one and official port one deliveries were made as part
of the Science Operations Plan implementation process for tour sequences
S19 and S20. In addition, preliminary port 1 was delivered for
sequences S21 and S22.

The first aftermarket process decision meeting was held as part of the
development process for tour sequence S01.

The Preliminary Sequence Integration and Validation (PSIV) 2 integrated
sequence with Inertial Vector Propagator commands merged in has been
delivered for cruise sequence C42. The final approval meeting will be
held the first week of January. The PSIV1 Seqgen products for C43 were
also released for review along with a sequence of events listing and the
space flight operations schedule.

The international astronomical community and Cassini investigation teams
will begin a program of cooperative, synergistic, ground based
observations of the Saturnian system. The program is planned as a
series of regular monitoring observations of Saturn beginning in 2004
from ground based observatories. In addition 17 orbits of Hubble Space
Telescope observation time have been obtained. The objective of this
program is to acquire a maximum amount of information about the state of
Saturn's atmosphere, which could be obtained by imaging and spectroscopy
at different wavelengths.

All teams and offices supported the Cassini Monthly Management review.
Delivery coordination meetings were held for the Instrument Operations
Remote Terminal Interface Unit /SEQTRAN V1.0 utility, and Cassini
Information Management System 3.0 (CIMS). The CIMS delivery provides
several functions in support of the Science Planning processes, the most
prominent of which is the Spacecraft Activity Sequence File / Science
Planning Attitude Spread Sheet comparison. This comparison typically
takes about eight hours to perform manually. CIMS 3.0 now does the
comparison in less than a minute.

On December 8, it was reported in a Southwest Research Institute News
Release that the Cassini Plasma Spectrometer (CAPS) has made the first
in situ observations of interstellar pickup ions beyond the orbit of
Jupiter. This is the first major discovery using data gathered by CAPS.
For more information go to:
http://saturn.jpl.nasa.gov/news/press-releases.cfm

Saturn will have its closet approach to Earth for the next 29 years on
December 31, 2003. At that time the planet will be about 1.2 billion
kilometers away with the rings tipped towards Earth. Reflected sunlight
will cause the planet to appear brighter than usual. For more
information go to:
http://science.nasa.gov/headlines/y2...dec_saturn.htm

Cassini 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, Calif., manages the
Cassini mission for NASA's Office of Space Science, Washington, D.C.

Cassini Outreach
Cassini Mission to Saturn and Titan
Jet Propulsion Laboratory
California Institute of Technology
National Aeronautics and Space Administration