Cassini Significant Events 11/15/01 – 11/20/01

The most recent spacecraft telemetry was acquired from the Goldstone
tracking station on Tuesday, November 20. The Cassini spacecraft is in
an excellent state of health and is operating normally. Recent
instrument activities include a Radio and Plasma Wave Science (RPWS)
High Frequency Receiver calibration, and the Visual and Infrared Mapping
Spectrometer (VIMS), Imaging Science Subsystem (ISS),
Cosmic Dust Analyzer, Magnetospheric Imaging Instrument and RPWS
instruments going to sleep mode for the Probe test. Engineering
activities taking place onboard the spacecraft this week include an
update to the Attitude Control Subsystem (ACS) Ka-Band and X-Band body
vectors. A minisequence was uplinked that will allow RPWS to operate
during the upcoming Gravitational Wave Experiment (GWE).

The multi-day Probe Relay test began this week. The purpose of this
series of tests is to validate parts of the revised Cassini-Huygens
mission plan, in particular the new parameters of the telecommunications
link between the Probe and the Orbiter. The tests are designed to
examine the system’s robustness to small variations in the
communications link that have not been accurately modeled on the ground.
Testing involves joint ESA-NASA teams at NASA’s Goldstone DSN facility,
at the European Space Operations Centre (ESOC) in Darmstadt, Germany,
and at the Cassini Mission Operations Center at JPL. Four of five tests
have been completed, and an initial assessment of the results indicates
no problems with telecommunications for the
revised mission plan.

Radio Science held a System Assessment Meeting (SAM) to determine the
readiness of the Radio Science System to support the GWE. The resolution
of the SAM was that the Cassini Program is ready to conduct the GWE.
Also in preparation for the GWE, Radio Science attended a delta design
review for the Cassini DSS-25 Upgrade Task. This delta-review closed
out several action items from September’s initial review.

Mission Assurance completed an extensive review of the Cassini Uplink
Process, with emphasis on process and procedural improvement. The
process is very thorough and well documented. Existing procedures are
currently under review for updates. Refinements will be discussed and
incorporated into individual procedures over the next month. Flight
Team training and re-certification will be scheduled following
completion of the documentation updates. The Multi Mission Image
Processing Laboratory (MIPL)/ Instrument Operations team completed
implementing and testing of software in preparation for MIPL delivery
27. This software includes updates to
both ISS and VIMS product generators; new programs to support
identification of policed data and VIMS cube backplane contents; and
support for Cassini to use existing MIPL Spacecraft, Planet,
Instruments, C-matrix, and Events kernel programs.

Mission Assurance attended the Ensure Mission Success Workshop. The
purpose of the workshop was to review high level processes and
practices, with the intent of establishing a set of institutional Flight
Practices. This workshop focused primarily on Systems Engineering and
Mission Assurance, and a follow-on workshop is scheduled for February
2002 to address other areas. A review was held for the Modules and
Target Options Requirements of the Mission Software System (MSS) D8
delivery. There was very good participation by the customers, and while
some Requests for
Action were submitted, none poses any problems to the MSS D8 schedule.
This review closes a major open item for proceeding with the D8
delivery, and the MSS development team expressed appreciation for the
support from the customers and Project in general in making the review a
success.

Twenty-six papers related to Cassini’s flyby of Jupiter are being
presented at the upcoming Division for Planetary Science of the American
Astronomical Society meeting in New Orleans. Four sessions have been
devoted to the topic of Galileo and Cassini at Jupiter. In addition, a
series of eleven papers on Cassini’s flybys of Venus and Earth will be
appearing in the December issue of Journal of Geophysical Research. This
issue will probably be out in mid-December, following the American
Geophysical Union meeting in San Francisco.