Cassini Significant Events for 05/01/03 – 05/07/03
The most recent spacecraft telemetry was acquired from the Goldstone
tracking station on Wednesday, May 7. 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://saturn.jpl.nasa.gov/operations/present-position.cfm .
On board activities this week included Trajectory Correction Maneuver 19
(TCM-19), Probe Checkout 11, High Rate Observations, High Frequency
Receiver Calibrations, an Instrument Expanded Block (IEB) exercise, and
a periodic instrument maintenance all for the Radio and Plasma Wave
Science instrument, uplink of IEBs for Visual and Infrared Mapping
Spectrometer (VIMS), a Cosmic Dust Analyzer (CDA) absolute turn
calibration, and several high water mark clears.
All activities before, during and after the TCM-19 burn executed
nominally, and all telemetry was as expected. The design burn time was
17.57 seconds. The maneuver terminated with a nominal accelerometer
shutdown after burning for 17.53 seconds.
TCM-19 was the first main-engine maneuver performed in over a year. The
primary purpose for this 1.58 m/s blow down maneuver was to satisfy the
400-day flushing requirement of the bipropellant propulsion system. The
maneuver also validated the new main-engine maneuver block to be used
for tour, and the ground processes that will be used during orbital
operations. The block is designed to be integrated within the tour
downlink passes. The ground processes demonstrated a rapid maneuver
design, and uplink of the maneuver on the same tracking pass upon which
the maneuver will execute. Additionally, several Saturn Orbit Insertion
(SOI) maneuver activities were demonstrated. These were 1) early closure
of the main-engine cover after the burn; 2) use of both dual drive
motors for cover closure; and 3) early turn-on of the oxidizer valve
heater after burn termination. TCM-19 allowed an opportunity for
checkout of what would otherwise be first-time events during SOI.
Probe Checkout 11 also executed nominally. Huygens personnel have
received all data from the checkout, and preliminary analysis indicates
that all Probe instruments are functioning as expected.
Various teams and offices supported this month’s Cassini / NASA
Quarterly Review.
The Spacecraft Operations Office (SCO) held a design review for the
Huygens probe release scenario. The scope of the review covered the
final probe-targeting maneuver through the release sequence and
spacecraft attitude recovery. The board, consisting of JPL and European
Space Agency personnel, approved the mission scenario and release
sequence design, and identified no major issues. There were sixteen
requests for further action, which will be closed during the course of
the release sequence development.
An Archive Design Peer Review of the Cassini Plasma Spectrometer (CAPS),
Ion and Neutral Mass Spectrometer (INMS), Magnetometer Subsystem (MAG),
and Radio Detection and Ranging (RADAR) instrument team archive plans
was held this week. Members of the Planetary Data System, instrument
team representatives, and Instrument Operations personnel attended.
A wrap up meeting was held for Science Operations Plan (SOP) development
of tour sequences S17 and S18. The sequence products have been archived
until August of 2005 when the SOP Update process will begin for S17.
SOP Update V&V completed this week, on schedule. Participating teams
have been queried throughout this activity for status and comments on
the processes and tools. The results have been compiled and will be
presented at the SOP U/D V&V wrap-up meeting next week. As part of the
process, Science Planning hosted a project briefing to outline the
modifications to S14, and to present Uplink Operations with a package
that officially “hands over” the sequence to the Science and Sequence
Update Process (SSUP).
Delivery Coordination Meetings were held for the redelivery of Mission
Sequence Subsystem (MSS) D9.0 On-Board Modules, Kinematic Prediction
Tool / Inertial Vector Propagator V9.0, MSS D9.0.1, and an update to the
command database. The MSS D9.0.1 Delivery Coordination Meeting had been
postponed one week to accommodate test and integration of a new command
database Version 9D. Two errors in Composite InfraRed Spectrometer
(CIRS) commands were uncovered last week while CIRS was testing their
V2.0.1 flight software checkout sequence. The commands are critical to
their checkout and although a workaround was possible, it was extremely
arduous. SCO quickly produced an updated database, tested, and delivered
it.
Cassini Outreach participated in judging High School Science Projects
relating to Earth and Space Science at the Los Angeles County Science
Fair, held at the LA Convention Center, and hosted an educator workshop
on Cassini for 25 master teachers attending a weeklong training session
in Pasadena, California.
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.
