From: LARRY KLAES (ljk4_at_msn.com)
Date: Fri Apr 16 2004 - 09:47:05 PDT
----- Original Message -----
From: Cassini Project<mailto:info_at_jpl.nasa.gov>
To: ljk4_at_msn.com<mailto:ljk4_at_msn.com>
Sent: Friday, April 16, 2004 12:15 PM
Subject: Cassini Update - April 16, 2004
Cassini Significant Events
for 04/08/04 - 04/14/04
The most recent spacecraft telemetry was acquired from the Goldstone
Science activities on-board for the duration of C44 include repetitive
The Cosmic Dust Analyzer performed the first time event of rocking downlinks
Development of S01, the first tour sequence, continued this week with a
Development of the S02 tour sequence began this week. A kick-off meeting
The flow of science planning processes for tour goes from Science Operations
A wrap-up meeting for implementation of tour sequences S25 and S26 was held.
At the Aftermarket Assessment meeting for S04, it was determined that very
Most waiver requests were approved at the S02 Project Briefing and Waiver
In the last week, 275 Imaging Science Subsystem (ISS) images and 23 Visual
The Cassini Program completed a two day Tour Operations Readiness Review.
The Operational Readiness Test #1 for Saturn Orbit Insertion (SOI) began
An ACS Flight Software (FSW) Review/Certification Requirements meeting was
The ACS team gave a presentation to the Cassini Project at the Mission
The Navigation team gave a presentation and recommendations at the Forum
Multi-Mission Image Processing Laboratory (MIPL) conducted a test of the
Three months before Saturn arrival, the Cassini spacecraft caught two storms
On 14 April 1629, 375 years ago, the Dutch scientist Christiaan Huygens was
Cassini is a cooperative project of NASA, the European Space Agency and the
Cassini Outreach
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: Fri Apr 16 2004 - 10:00:44 PDT
tracking station on Tuesday, April 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
http://jpl.convio.net/site/R?i=7XTf710YP6xO-3BCLCXxIg
blocks of imaging with occasional riders, a few Ultraviolet Imaging
Spectrograph system scans and a sprinkling of optical navigation (OPNAV)
images. The results will be Saturn approach movies to study the planet's
atmosphere and its temporal variations, searches for new satellites,
observations of Titan, searches for diffuse ring material and system scans
to map atomic species.
this week. All subsystems reported normal performance and results are
undergoing evaluation. Additional on-board activities included a Radio and
Plasma Wave Science High Frequency Receiver Calibration and an ACS Reaction
Wheel Assembly bias unload.
waiver for SSR Data Load command timing constraints for OPNAV IEB loads
approved at the Preliminary Sequence Integration and Validation (PSIV)
waiver disposition meeting. This concluded the PSIV1 development phase.
PSIV2 began with a sequence change request approval meeting. Thirty-two
change requests for the sequence were dispositioned.
was held, merged reference activity plan files containing the Inertial
Vector Propagator and Star ID suspend commands delivered, and the remaining
engineering commands, science activities, and Sub-Sequence Generation
Spacecraft Activity Sequence Files released.
Plan (SOP) Implementation, to Aftermarket, and on to SOP Update. This week,
there were significant development milestones in all processes for multiple
tour sequences.
The sequences have now been archived and will begin the Aftermarket and SOP
Update processes in the summer of 2006. In addition, official input port #1
for SOP Implementation of tour sequences S27 and S28 occurred this week.
The delivered sequence products were merged and handed off to the ACS team
for a complete end-to-end pointing analysis.
few changes had been submitted by participating teams. As a result, it was
decided that the Decision Meeting was to be canceled and all requested
changes approved unless the Saturn target working team identifies any major
issues in incorporating the requested changes.
Disposition meeting. A few were delayed until an end-to-end C-kernel could
be delivered that included the attitude profile during the Saturn Orbit
Insertion (SOI) burn period. This process has now been completed and a
hand-off product was delivered to Uplink Operations for the start of the
Science and Sequence Update process. In addition, a kick-off meeting was
held for S03 SOP Update. The scheduled Science Adaptation Panel (SAP)
meeting was canceled as all requested DSN station coverage for this sequence
has been received.
and Infrared Mapping Spectrometer (VIMS) cubes were returned and
distributed, bringing the total of images acquired since the start of
Approach Science up to 2888, and the number of cubes up to 697.
The objective of the review was to evaluate the readiness of the Mission
Operations System and Ground Data System to support Tour operations. All
teams both at JPL and remote sites presented their readiness status. The
board agreed that Cassini was well prepared for tour, and that the work
remaining was appropriate.
last Friday in the Integrated Test Lab. This test is the dry run of all
nominal events that will start for real on June 2 and continue through July
3, 2004. This week the test covered loading the sequence onto the Solid
State Recorders and performing Trajectory Correction Maneuver #21.
held this week. The FSW was accepted for operational use with two follow-up
documentation actions assigned. A8.6.7 will support SOI, and another planned
FSW build/parameter set, A8.7.0, is scheduled to support the Huygens probe
mission. An uplink readiness review for A8.6.7 will be held next week.
Planning Forum on the use of a hybrid ACS control system. This is a future
potential contingency. The presentation explored the spacecraft
capabilities when operating with a reduced set of reaction wheels and using
Reaction Control Subsystem thrusters for selected axes.
concerning modifications to the reference trajectory. This was a revisit of
the implications of raising the T3 altitude and subsequent trajectory and
flyby altitude changes.
critical OPNAV downlink process. The test involved automated queries of the
Real-time stream and, in parallel, the more manual contingency process. The
automated process stopped early and delivery was delayed by a restart. The
contingency process worked as planned and Navigation received the data
within 30 minutes of initial receipt by MIPL.
in the act of merging into one larger storm. This is only the second time
this phenomenon has been observed on the ringed planet. A series of Cassini
images documenting this event is available on the Internet at
http://jpl.convio.net/site/R?i=-Fho3xM_UlZO-3BCLCXxIg
born. The European Space Agency (ESA) probe on-board the NASA/ESA/ASI
Cassini-Huygens mission to the Saturnian system is named after this
lens-maker who discovered Titan in 1655. For more information on Christiaan
Huygens and the anniversary of his birth go to:
<http://jpl.convio.net/site/R?i=ybe1JKxcbCBO-3BCLCXxIg
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.
Cassini Mission to Saturn and Titan
Jet Propulsion Laboratory
California Institute of Technology
National Aeronautics and Space Administration