Cassini Significant Events 07/20/11 - 07/26/11
Title: Cassini Significant Events 07/20/11 -
The most recent spacecraft telemetry was acquired on July 25 from
the Deep Space Network tracking complex at Goldstone, California. The
Cassini spacecraft is in an excellent state of health and all
subsystems are operating normally. Information on the present position
and speed of the Cassini spacecraft may be found on the "Present
Position" page at:
Wednesday, July 20 (DOY 201)
An Autorad Project Interface Test with the DSN was successfully
performed yesterday over the Goldstone DSS15 pass. One more
demonstration will be performed using larger Spacecraft Message Files
(SCMFs), followed by Cassini's operational use of Autorad, which will
be for the auto-radiation of some of the commands files being sent to
A Delivery Coordination Meeting was held today for the initial
delivery of the Events software. Events Version 1.1 locates in the
spacecraft trajectory instances of specific geometrical and physical
events of interest to science opportunity analysts. These may involve
the spacecraft as well as planetary objects such as planet,
satellites, rings, and magnetosphere. Its principal uses in Cassini
operations are for generation of the Tour Atlas when a new trajectory
is released and for analysis of timing changes for movable block
epochs tied to geometric events. The product of EVENTS execution is an
output file which contains times and durations of the specified events
in chronological order, as well as an events summary.
Thursday, June 21 (DOY 202)
Starting this week's observations, the Imaging Science Subsystem (ISS)
performed astrometric observations of the small moons Calypso,
Polydeuces, Helene, Pandora and Epimetheus. Next, around apoapsis, the
Ultraviolet Imaging Spectrograph (UVIS) completed a 32 hour system
scan of Saturn's magnetosphere to image hydrogen and oxygen in the
Saturn system. The Cosmic Dust Analyzer (CDA) completed a 26.5 hour
interstellar dust observation, and the Visual and Infrared Mapping
Spectrometer (VIMS) and ISS performed two 11-hour exoplanet transit
observations. ISS, the Composite Infrared Spectrometer (CIRS), and
VIMS performed another observation in the Titan monitoring campaign.
Ending the week, ISS performed one more set of astrometric
observations of small moons, this time imaging Atlas and Janus among
others, and CIRS began a 23 hour mapping activity to determine the
upper troposphere and tropopause temperature of Saturn.
Friday, July 22 (DOY 203)
The Navigation team delivered a special trajectory prediction product
today in support of a Radio Science Subsystem (RSS) Saturn occultation
observation planned for Aug. 1.
In the last week, 130 ISS images and 1,406 VIMS cubes were generated
and distributed. Since Jan. 2004, when Saturn Approach Science began,
247,649 ISS images and 121,693 VIMS cubes have been received. VIMS
returned a MODE_SYNC_ERROR just after trigger 48 executed, which may
account for one missing cube. The trigger was executed on ground
support equipment but the error could not be reproduced.
Saturday, July 23 (DOY 204)
The Spacecraft Operations team (SCO) lowered the best lock frequency
today by 1.2 kHz. This was to match a gradual drift down in the
Telecom Deep Space Transponder Static Phase Error (SPE).
Sunday, July 24 (DOY 205)
The Cassini iPhone App is now available. The Cassini app was designed
to give an overview of the spacecraft's current activities, starting
with the latest images. Also included in the app is the 'Present
Position' of the spacecraft, as well as a countdown to the next major
event - usually a targeted flyby of one of Saturn's moons. For more
information on this subject, link to:
Monday, July 25 (DOY 206)
The Attitude and Articulation Control Subsystem (AACS) custom
telemetry schedule was updated today to include the provision of
delta-V estimates every 512 seconds from any thruster firings that may
have occurred, such as in support of RWA wheel speed biases.
The second version of AceLog, the replacement tool for the legacy
operations log (Olog), was successfully installed in operations today.
In addition to smart features that help the project Ace, Acelog V2.0
adds more user interface enhancements and performance improvements,
and is capable of monitoring real time data.
A software patch to the Cassini Information Management System (CIMS)
Version 3.6.2 was installed today to correct a bug introduced in the
deployment of the Oracle 11g upgrade last week.
Tuesday, July 26 (DOY 207)
The most recent Cassini-Huygens Analysis and Results of the Mission
(CHARM) teleconference was held today. The topic: "Cassini
Huygens Mission to Saturn - Seventh Anniversary - Part 1 -
Mission Overview, Highlights of Magnetospheric Science, Titan, Icy
Satellites, and Saturn." A PDF of the presentation package may be
An audio recording of the presentation was made and will be linked to
the same location within a few days.
Scientists met at Caltech for a workshop on Titan surface studies
yesterday and today, as well as for a workshop on dunes today and
Port 2 products were due today as part of the S71 Sequence
Implementation Process (SIP). The products will be merged and sent out
to the flight team for review.
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