Cassini Significant Event Report

For Week Ending 01/01/99


Spacecraft Status:


The most recent spacecraft status is from the DSN tracking pass on
Tuesday, 12/29, over the Goldstone tracking station. The Cassini
spacecraft is in an excellent state of health and is executing the Cruise
11 sequence normally. The speed of the spacecraft can be viewed on the "Where is Cassini Now?" web page (http://saturn.jpl.nasa.gov/operations/present-position.cfm)


Spacecraft Activity Summary:


On Thursday, 12/24, the Probe Support Avionics (PSA) prime status was
reset. This activity follows each Probe Checkout (PCO).


On Sunday, 12/27, Instrument Checkout (ICO) began. The first ICO
activities involved the successful maneuver of the Spacecraft to a High
Gain Antenna (HGA) to Earth point attitude. Once two-way communications
was established using the HGA, the Probe data from PCO #3 that was stored
on the SSR was played back, and a realtime command to clear the AACS High
Watermarks was uplinked to the spacecraft.


On Monday, 12/28, the Radio Science Subsystem (RSS) began ICO activities
with Ultra Stable Oscillator Test #1. The test was extremely successful
and was the first time ever for three frequencies (S-Band, X-Band, and
Ka-Band) to be simultaneously downlinked from a single spacecraft and
recorded on the ground.


On Tuesday, 12/29, RSS performed its second test, a repeat of USO test #1
but without Ka-band transmission.


Upcoming events:


The events planned for the next reporting period consist primarily of a
continuation of the ICO activities. RPWS, MAG, CDA, MIMI, CAPS, INMS,
UVIS, and continued RSS tests are the principal participants.



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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