Cassini Significant Events for 04/04/02 – 04/10/02
The most recent spacecraft telemetry was acquired from the Goldstone
tracking station on Wednesday, April 10. 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/cassini/english/where/ .
Instrument activities this week included periodic instrument maintenance
for the Radio and Plasma Wave Science subsystem, and an Ultraviolet
Imaging Spectrograph Hydrogen Deuterium Absorption Cell conditioning
exercise. The purpose of conditioning is to regularly exercise the H
and D cell filaments. Additional spacecraft activities included clearing
of the ACS high water marks, and an ACS periodic engineering maintenance
(PEM). The PEM contains the main engine gimbal actuator exercise,
Backup ALF Injection Loader maintenance, and backup reaction wheel
exercise. Results of the PEM were as expected.
The first Science Planning Team input port for C33 occurred this week.
Process output files will now be merged and delivered to ACS for
pointing validation runs.
A Saturn Orbit Insertion (SOI) Target Working Team met for the first
time this week. Integration work has begun on the period immediately
following SOI. A Science Operations Plan (SOP) implementation Tiger Team
met to explore an alternate approach of developing four tour sequences
in two Science Planning Team processes. Some issues were identified and
will be worked over the next couple of weeks. In general, this approach
was agreed to be a good option since it reduces the number of processes
and overhead associated with implementing the SOP.
The Spacecraft Office held a maneuver wrap-up meeting after Trajectory
Correction Maneuver (TCM) 18. At this meeting it was confirmed that the
TCM performance was nominal. The team reviewed the new tour processes
that were used in the design of this TCM to identify desired
improvements or lessons learned.
A Flight Software Monthly Management Review was held this week.
Development progress for Saturn Orbit Insertion, Huygens Probe Relay,
ACS flight software, and CDS flight software were reviewed. All items
are proceeding as scheduled.
Uplink Operations personnel made a presentation to Program Management
for performing a tour Science and Sequence Uplink Process (SSUP)
Verification and Validation (V&V) activity in mid 2003. A series of
smaller pre-tests and demonstrations was proposed, culminating in a
full-up SSUP demonstration mid-year.
To make the needed personnel available, the proposal included plans to
create a minimal set of activities in C38, moving most of them into C37
and C39. V&V would then be performed during the C38
development/execution period. Program Management approved the plan, and
directed the team to proceedas proposed.
All of the planned Mission Sequence Subsystem D8 deliverable
applications are in hard-freeze and system testing is proceeding as
planned. May 8, 2002, is still a firm date for the delivery to support
the May 13, 2002, start of Science Operations Plan integration.
User acceptance testing for the Cassini adaptation of the Command System
Version 26.4 was completed this week. An in-flight demonstration was
also performed. Additional demonstrations have been scheduled for mid
April and early June.
A scale model of the Huygens Probe is now on loan to the Space Center
Museum in Houston, Texas. The model will be part of a summer exhibition
and will be returned to the Space Flight Operations Facility at JPL for
display in September.
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.
