Cassini Significant Event Report

For Week Ending 10/03/03

The most recent spacecraft telemetry was acquired from the Madrid tracking station on Wednesday, October 1. The Cassini spacecraft is in an excellent state of health and is operating normally. Information on the spacecraft's position and speed can be viewed on the "Present Position" web page.

On-board activities this week included a Radio and Plasma Wave Science High Frequency Receiver calibration and execution of Trajectory Correction Maneuver (TCM) 19b.

The maneuver executed normally on October 1, 2003. This TCM was an in-flight verification of the energy burn cutoff algorithm and the yaw steering that will be used for Saturn Orbit Insertion. The main engine burn duration was 21.8 seconds, with a burn magnitude of 2.015 meters/second.

Alcatel Space Systems hosted the fifth Huygens progress meeting in Cannes. A number of technical issues regarding the Huygens mission were discussed. The most important outcome of the meeting was the decision to baseline the pre-heating option. The purpose of pre-heating is to warm the data system circuitry to further reduce the doppler effect which has troubled the link performance. Pre-heating is accomplished by powering the probe four hours prior to entry at Titan. All analyses show that there are sufficient power reserves and that the mission is completely robust to this option.

Science Planning hosted a kick-off meeting for Science Operations Plan implementation of the S05 and S06 tour sequences, and a post process wrap-up meeting for sequences S03 and S04.

Preliminary and official port 1 deliveries were completed as part of the cruise C43 science planning team process.

Uplink Operations presented the current plan and timeline for the Science and Sequence Update Process at this week's Cassini Design Team meeting. A number of modifications and lessons learned identified through the August Verification and Validation activity have been incorporated.

System Engineering attended a workshop sponsored by Deep Space Mission Systems and Consolidated Space Operations Contract (CSOC) to redesign the current DSN allocation process. The implementation will occur between now and the end of the calendar year. The current CSOC contract expires in December.

The Outreach Team gave two talks at Polytechnic High School in Long Beach, California to 250 high school students, and supported the Los Angeles County Fair.

Science results from the Cassini Radio Science Team were published this week in Nature. The article "A test of general relativity using radio links with the Cassini spacecraft" may be accessed at A more general overview may be viewed at

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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