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Significant Event Report for Week Ending 12/19/2003

Cassini Significant Event Report

For Week Ending 12/19/03

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/operations/present-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/y2003/12dec_saturn.htm

Additional information about Cassini-Huygens is online at http://saturn.jpl.nasa.gov.

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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