Status Report

NASA Cassini Significant Events for 01/08/04 – 01/14/04

By SpaceRef Editor
January 16, 2004
Filed under , ,
NASA Cassini Significant Events for 01/08/04 – 01/14/04

The most recent spacecraft telemetry was acquired from the Goldstone
tracking station on Tuesday, January 13. 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 .

Cruise sequence C40 concluded this week with uplink of a trigger
mini-sequence for the Composite Infrared Spectrometer (CIRS), start of
execution of the Cassini Plasma Spectrometer (CAPS) Solar Wind
mini-sequence, uplink of instrument expanded blocks (IEB) in support of C42,
and uplink of the C42 background sequence.

C42 began execution on Friday, January 9. Initial activities included
instrument wake-up and IEB loads, an Ion and Neutral Mass Spectrometer
pressure test, uplink of Cosmic Dust Analyzer (CDA) flight software version
9.2, CAPS and Radio and Plasma Wave Science solar wind observations, CDA
articulations, and a reaction wheel unload.

With the start of C42, the Cassini orbiter has begun its Approach Science
phase. The previous "cruise" phase included instrument calibrations and
infrequent science opportunities. Approach Science consists of a set of
continuous science observations between now and Saturn Orbit Insertion in
July 2004. The level of science activity is representative of the upcoming
Tour phase, and the flight team will be using tour processes and operational
modes as expected in tour operations.

One of the features of the Approach Science phase is a month-long campaign
to monitor the solar wind impinging on Saturn’s magnetosphere using CAPS,
the Magnetometer Subsystem (MAG), and the Magnetospheric Imaging Instrument
(MIMI) while monitoring Saturn’s auroral radio emissions with RPWS. MIMI
and RPWS will look for upstream waves and particles, or disturbances in the
solar wind caused by its interaction with Saturn’s magnetosphere. The
Hubble Space Telescope will also be carrying out a campaign at this time to
monitor Saturn’s ultra violet emissions periodically. The goal of these
observations is to understand how Saturn’s magnetosphere responds to changes
in the solar wind. For the remainder of the Approach Science phase, the
Magnetospheric and Plasma Science (MAPS) instruments will continue to
monitor the solar wind but from a less-advantageous orientation while
continuing to monitor Saturn’s radio emissions and search for upstream waves
and particles. Throughout, CDA will look for Saturn dust streams similar to
those emanating from Jupiter.

Remote sensing observations during the Approach Science phase include Saturn
ring and atmospheric movies by the Imaging Science Subsystem (ISS) and the
Visual and Infrared Mapping Spectrometer (VIMS), searches for new satellites
and their orbit determinations by ISS, extended Ultraviolet Imaging
Spectrograph (UVIS) system scans to search for hydrogen emissions, CIRS ring
and Saturn atmospheric composition measurements, and optical navigation
images to refine the ephemeredes of the known satellites. During the last
month of this phase, monitoring by ISS of Titan’s surface and clouds will
begin, along with diffuse ring observations to search for unidentified ring
hazards close to the planet.

This month we are executing the month-long MAPS campaign. Next month we
start Optical Remote Sensing observations, and more MAPS.

As part of the C43 development process, uplink operations personnel (ULO)
began the processing of IEB loads. No waiver disposition or Science
Allocation Panel meeting was held during the C43 Preliminary Sequence
Integration and Validation 1 phase process as no additional waivers were
submitted, and the DSN allocation file did not require any changes to the
SSR management strategy. ULO is working with the Spacecraft Operations
Office to build and test command files for the Probe Relay demonstration to
be executed in C43. Over 40 real time command files are required for this

A waiver disposition meeting and a final wrap up meeting were held as part
of the Science Operations Plan (SOP) implementation process for tour
sequences S19/S20. The S19/S20 products are now archived, and will be
reactivated for execution in March, April, and May of 2006.

Official port #1 occurred for SOP implementation of S21/S22. The merged
Spacecraft Activity Sequence File (SASF) is now being run through Inertial
Vector Propagator (IVP)/ Kinematic Prediction Tool (KPT) to validate the
end-to-end pointing profile. The S23/S24 SOP Implementation process kicked
off this week and will complete on March 11, 2004.

The next process to follow SOP Implementation in the development of a tour
sequence is the Aftermarket process. This 5-week process addresses both
mandatory and proposed discretionary changes that would require
re-integration of segments contained in a sequence. The proposed changes
would include requests by science and engineering that involve modifications
to key shared resources including, but not limited to, spacecraft attitude,
data volume, observing time, op modes, telemetry modes, and waypoints.
After the cutoff for changes has been reached, an assessment meeting chaired
by the Project Scientist is held to scope out the proposed changes. Later
in the process a final decision meeting is held on what changes will be made
to the sequence plan. The appropriate Target Working Team or Orbiter Science
Team will then integrate approved changes. If it turns out that no
discretionary changes are requested, the Aftermarket process for that
sequence is cancelled and the sequence developed as part of the SOP
Implementation process moves on to SOP Update.

All approved Aftermarket changes have been accommodated for tour sequence
S01 and the process has completed. The S01 SOP Update Process will begin on
January 30, 2004. All requested S02 Aftermarket changes were received this
week. The S02 Aftermarket Assessment meeting will be held next week to
review the scope of the requested changes.

The final port#3 occurred as part of the C44 Science Planning Team process.
C44 is the last approach science sequence before the start of tour with S1.
The merged SASF for C44 is now being run through IVP/KPT to validate the
end-to-end pointing profile. This process will end this week and will be
followed immediately with the C44 Science and Sequence Update Process
beginning on January 20.

All teams and offices supported this week’s Cassini Monthly Management

The Project Scientist released a draft agenda for the Project Science Group
meeting to be held at the California Institute of Technology in Pasadena,
California the last week of January.

Cassini is a cooperative project of NASA, the European Space Agency and the
Italian Space Agency. The Jet Propulsion Laboratory, a division of the
California Institute of Technology in Pasadena, Calif., manages the Cassini
mission for NASA’s Office of Space Science, Washington, D.C.

SpaceRef staff editor.