Cassini Significant Events 07/06/06 - 07/12/06

July 14, 2006

(Source: Cassini Project)


The most recent spacecraft telemetry was acquired Wednesday, July 12, from
the Madrid tracking stations. 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 .

Thursday, July 06 (187):

A brief summary has been released from the executive session of last month's
Project Science Group (PSG) meeting. Two of the topics discussed were
extended mission planning, and high-value data insurance. For extended
mission, tour classes P, O, and Q were designated for further development.
It is planned that a number of specific tours in these classes will be
developed for the next PSG meeting in October of this year.

Regarding the protection of high-value science, the possibilities and
effects of salvaging data recorded on the spacecraft but, through error or
failure, not transmitted to or captured on the ground were discussed.
Concerns about additional workload were voiced. Mission Planning took an
action to explore and develop information on the several approaches possible
and estimates of their impacts on available resources both within JPL and at
the distributed operations sites. The results of this will also be
presented at the next PSG meeting.

On Thursday, July 6, a 13.5 hour Ultraviolet Imaging Spectrograph (UVIS)
observation of Saturn was performed. This is a slow scan of Saturn across
Saturn's visible hemisphere, at a high phase angle to form spectral images
at a Saturn distance of two million kilometers. Near the end of the day,
Optical Navigation (Opnav) images were obtained of Saturn's moons against
the background star field. These images help determine the spacecraft
trajectory as well as the orbits of the satellites.

Friday, July 07 (DOY 188):

A final approval meeting was held today for the "h" version of the S22
background sequence. The sequence leads were in the process of polling
participants for their "OK" to uplink when proceedings were interrupted by a
fire drill! Leads received a number of approvals and a waiver comment via
email after the drill was over. Update: The sequence was finally declared
approved on Tuesday, July 11.

Monday, July 10 (DOY 191):

Mission Support and Services Office (MSSO) personnel periodically must
upgrade components, operating systems, software, and whatever else is
necessary in order for the Cassini ground system to remain current and to
advance in capability. This is by no means a simple task. Recently new
Telemetry, Tracking, Command & Data Management (TTC&DM) software was
delivered to the Project. It then went through a rigorous user
acceptance-testing program prior to acceptance of the delivery. MSSO must
now coordinate with the flight team for upgrade to the individual
workstations that run the software. All of the machines for Instrument
Operations (IO) and about half of the machines for the Spacecraft Operations
Office, Uplink Operations, and the ACEs have been upgraded. IO and MSSO are
coordinating the upgrade of machines used by the scientists at the
distributed operations sites. The first upgrade has been made to one of the
machines used by UVIS. Others will follow along shortly.

Tuesday, July 11 (DOY 192):

Cassini reached apoapsis, the farthest point, in our 26th orbit of Saturn
today. Almost all of the day was taken up by a Composite Infrared
Spectrometer (CIRS) observation of Saturn. CIRS spent 21 hours taking
mid-infrared images of Saturn's upper troposphere, mapping it with high
spatial resolution.

A kick-off meeting was held today as part of the final sequence development
process for the S24 background sequence. Merged products from the Science
Operations Plan update process were made available in the file repository
along with stripped Spacecraft Activity Sequence Files for the participating
teams to populate and return to the sequence leads.

A beautiful image of Rhea against Saturn's crescent with an edge-on view of
the rings is Astronomy Picture of the Day today.

Wednesday, July 12 (DOY 193):

The S22 SSR and instrument-direct instrument expanded block (IEB) loads were
uplinked successfully on Tuesday and early Wednesday morning. The uplinks
had all originally been scheduled for Tuesday. DSS-14 had been red just
prior to the start of track but the DSN believed it would be available for
Cassini to use. Unfortunately, a partial loss of the DSS-14 track did
occur. The DSN operators worked valiantly to restore the antenna so only
about 3 hours were lost before the antenna was recovered shortly before
192/19:50. There is always a backup pass scheduled when uplinking IEBs to
cover just this sort of contingency, so Wednesday's track beginning at 2:00
AM came in very handy. Uplink of the background sequence is scheduled for
July 14 with a backup pass on July 15.

A delivery coordination meeting was held today for version 1.5.2 of the
electronic command request form. This is a point delivery to accommodate a
Spacecraft Operations Office (SCO) request to allow Maneuver Automation
Software to generate requests for reaction wheel bias commands in the event
of a maneuver cancellation.

An Encounter Strategy Meeting for the Titan 16 and Titan 17 flybys was held
today. The meeting addressed mission, sequence, navigation, spacecraft, and
instrument overviews and status for maneuvers 68-70, and the time period
from July 22 through September 7.

Cassini Outreach presented "Cassini's Halftime Highlights" to 60 enthusiasts
at the Sonoma County Astronomical Society at Proctor Terrace Elementary
School, Santa Rosa, CA. Cassini Outreach material was handed out to all
attendees.