Spacecraft in excellent health and operating normally
The most recent spacecraft telemetry from Cassini was acquired
from the Goldstone tracking station on Wednesday, October 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 the FMI link below.
On-board activities this week featured more varied Imaging
Science Subsystem (ISS) observations than in previous weeks. In
addition to movies of Saturn's rings, ISS performed a global color
map of Iapetus, numerous observations of small satellites used for
orbit determination, diffuse ring images, and Phoebe
spectrophotometry. The Ultraviolet Imaging Spectrograph (UVIS)
observed a stellar occultation interior to the B ring, which
provided a high-resolution study of low optical depth regions.
Commands were approved and uplinked to the spacecraft this week
to perform a live update for Iapetus, to turn off the
Magnetospheric Imaging Instrument collimator, perform a Cosmic Dust
Analyzer decontamination, and clear a global variable as part of
the scheduled cleanup after the Attitude Control Subsystem (ACS)
8.7.1 flight software update and ACS flight computer swap. The
Iapetus live update executed on October 15, with closest approach
on October 17. The S04 background sequence will then conclude on
The Spacecraft Operations Office ran a successful test of the
Iapetus Live Inertial Vector Propagator (IVP) Update in the
Integrated Test Laboratory (ITL) this week. The Flight Software
Development System (FSDS) run also completed successfully. The ACS
data from the test was reviewed and the files were verified for
uplink. The pointing difference, during the Iapetus observation,
between the FSDS C-Kernel and the Preliminary Sequence Integration
and Validation (PSIV) 2 C-Kernel is 4.1 mrads. This is consistent
with known ephemeris differences.
Science Planning has adjusted the schedule for Science
Operations Plan (SOP) Implementation deliveries. The decision to
modify the schedule was made in order to provide relief to the
flight team as they support additional workload on the sequence
development process as a result of last week's update of the
Cassini reference trajectory. The only deliveries affected are for
the last five sequences of the tour, S37 through S41. Preliminary
port 2 for S37/S38 occurred on Friday of last week. The next
delivery in support of SOP Implementation occurs on November
The official port for the S08 SOP Update process occurred this
week. The products were merged and delivered to the ACS team for
end-to-end pointing validation. The Titan Orbiter Science Team
(TOST) and Satellite Orbiter Science Team (SOST) met to begin to
re-integrate the Titan b, Titan 3, and Enceladus-4 flybys.
A Program internal science talk was given this week on recent
ISS satellite discoveries. The presentation covered why instrument
teams are interested in locating additional satellites, and the
process used by the imaging team to find them.
S05 development had the tightest time constraints for
modifications as a result of the release of the new reference
trajectory. Last week the Sequence Team (ST) participated in a
Sequence Change Request (SCR) approval meeting, command approval
meeting for the Instrument Expanded Blocks to be uplinked to the
spacecraft, and a final sequence approval meeting.
In the last week, stripped subsequences were produced for use in
the final FSIV merge, the merge was produced, products generated,
and the Sequence of Events listing and Spaceflight Operations
Schedule were generated. All this was done with no slip to the
development schedule. An unexpected benefit of the new reference
trajectory was the determination made by Science Planning that a
live IVP update would not be necessary during S05, and thus, no ITL
testing for those additional products would be required. The ST
Lead has expressed much appreciation for all the hard work everyone
put in to get this sequence out on time. S05 begins execution on
Monday. October 18.
The Instrument Operations and Multi Mission Image Processing
Laboratory have begun preparations to support the display of
Titan-a ISS and VIMS data in near real-time. Interaction with Media
Relations, JPL Audio/Visual, and Cassini Outreach are underway.
Mission Planning has released a Titan-a mission description. It
is a brief, concise description of the Titan-a encounter events,
including an estimated playback schedule for all instruments.
Delivery meetings were held this week for Maneuver Automation
Software (MAS) 4.5, MDT V8.1, and MAPDF_GEN V8.1. In addition, a
delivery coordination meeting was held to review RADAR build-5
ground software to be used to process the Ta data. The software has
been tested and is ready for use.
The Mission Support & Services Office (MSSO) reported that
last week the Flight Control Team supported 7 DSN passes, and
uplinked 21 command files to the spacecraft.
Laminated images representing the Cassini-Huygens spacecraft
during Saturn Orbit Insertion, a map of participating countries,
and a selection of images will be included in a time capsule
celebrating the 50th anniversary of the North Museum of Natural
History and Science in Lancaster (PA). The capsule information will
be displayed at the museum October 16-17. The selected images are
on the Cassini Multimedia webpage, on the second FMI link
Cassini Science Planning presented "Cassini-Huygens: The Real
Lord of the Rings" during DePaul University's Space Sciences
symposium for 150 K-12 educators, and again at the Swift Art
Gallery, Los Angeles, for 40 members of the public.
Cassini Science Planning participated in "Journey Week" in
Menominee, Michigan. During the week-long event, 1,727 students and
72 teachers and adults from eight different elementary, middle and
high schools learned about the Cassini-Huygens mission and its
exciting science results. This is the second year Cassini has
participated in this program.
Science Planning and Huygens Probe Science & Engineering
staff co-led a Solar System Ambassador Training class. This
two-part training session focused on Titan and the Probe Mission.
Over 50 members of the Ambassador network were trained on these