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Significant Event Report for Week Ending 1/22/1999

Cassini Significant Event Report

For Week Ending 01/22/99

Spacecraft Status:

The most recent spacecraft status is from the DSN tracking pass on
Thursday, 01/21, over the Madrid tracking station. The Cassini spacecraft
is in an excellent state of health and is operating nominally. Instrument
Checkout (ICO) has now completed with all objectives met! 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 Friday, 01/15, the High Gain Antenna was turned to Earth point and
commands were sent to retrieve the science data onboard. Following this,
five mini-sequences were sent accomplishing the power on and IEB Loads for
MAG, RPWS, UVIS, ISS and VIMS. CDA was then powered on a short time later.

On Saturday, 01/16, the C11 background sequence was successfully
reactivated. Today's ICO activity was the imaging of SPICA (Alpha
Virginis) with the ISS, UVIS, and VIMS instruments. A 4x4 mosaic was
produced. The data set received indicates excellent alignment between the
two cameras (NAC and WAC), as well as excellent pointing by AACS.

On Sunday, 01/17, RSS USO Test #4 was successfully performed, High Water
Marks were cleared and the ISS (NAC & WAC), UVIS, and VIMS were powered
OFF as planned.

On Monday, 01/18, Radar Checkout was performed and the RPWS and MAG
instruments were powered OFF, as planned.

On Tuesday, 01/19, MIMI and CAPS performed a High Voltage Turn-on test via
real time commands. This occurred concurrently with RSS Test D.

On Wednesday, 01/20, RSS Test E was performed (this test included a
successful Ka-Band uplink from DSS-13 with successful downlink with
Ka-Band, two way lock). The CDA instrument was powered OFF as planned, and
MIMI and CAPS checkout activities continued. The MIMI Auto High Voltage
turn on sequence performed as desired making use of realtime commands
unnecessary for this activity in the future.

On Thursday, 01/21, INMS Checkout was successfully executed, the CAPS,
MIMI, and INMS instruments were powered OFF as planned, an additional S&ER
3 Test was performed validating the capability to lock up on the RTE_1896
realtime telemetry mode, communications were established with the
spacecraft via LGA-1, the High Gain Antenna was pointed to the sun,
Cassini reverted back to "nominal" inner cruise spacecraft configuration,
and the C12 sequence was uplinked.

Upcoming events:

Activities scheduled for the week of 01/22-01/28 include: SSR Flight
Software Partition Maintenance and deregistration of the C11 sequence on
01/22, C12 background sequence begins executing on 01/24, Periodic
Instrument Maintenance beginning on 01/25, and an AACS Paramater Update in
support of TCM-6 followed by a SSR Pointer Reset both on 01/26.

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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