Cassini Significant Events -- for 06/16/05 - 06/22/05

June 24, 2005

(Source: Cassini Project)

The most recent spacecraft telemetry was acquired Wednesday from the
Goldstone 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 .

Activities this week:

Final science activities in the S11 sequence included Composite InfraRed
Spectrometer (CIRS) and Imaging Science Subsystem (ISS) observations of the
F-Ring, ISS movies of Saturn's southern hemisphere, and low-rate
magnetospheric surveys performed by the Magnetospheric and Plasma Science
(MAPS) instruments.

Beginning on Friday, the entire suite of MAPS instruments, which include the
Cassini Plasma Spectrometer (CAPS), Cosmic Dust Analyzer (CDA), Ion and
Neutral Mass Spectrometer (INMS), Magnetometer Subsystem (MAG),
Magnetospheric Imaging Instrument (MIMI) and Radio and Plasma Wave Science
(RPWS), simultaneously performed low-rate outer magnetospheric surveys to
observe the variability of magnetospheric boundaries at several
geometrically similar apoapses.

On Saturday the RADAR instrument obtained distant full-disk radiometry of
Titan to help constrain the thermal properties of the surface.

Optical remote sensing activities this week included ISS movie feature
tracks of Saturn's winds and clouds in the southern hemisphere, a Visual and
Infrared Mapping Spectrometer (VIMS) mosaic of the entire ring system near
apoapsis, Ultraviolet Imaging Spectrograph (UVIS) observations to detect
flashes from meter-sized interplanetary impactors on Saturn's rings in order
to constrain the flux of impact population for the ring's origins and
evolution, and CIRS integrations of the rings to constrain their thermal
properties, and determine their composition.

Thursday, June 16 (DOY 167):

member of the Cassini Science Team gave a presentation on unraveling the
secrets of Saturn's moons. Because Nature often yields her secrets through
the most bizarre examples, the talk focused on the unusual satellites
Enceladus and Iapetus, the violent events that shaped these satellites,
their connection to Earth, the stars, and life itself.

The S15 Science Operations Plan update process kicked off today. It will
run for about five weeks and will conclude mid-July.

A kick-off meeting for the DOY 177 Live Inertial Vector Propagator (IVP)
update and live moveable block (LMB) process was held today. The Navigation
team delivered the orbit determination files by end of day and the flight
team will spend the next few days reviewing them. A Go/No Go meeting will
be held for the update on Monday

Uplink Operations (ULO) radiated a real-time command for an overlay to the
Reaction Wheel Assembly bias that will execute tomorrow.

Friday, June 17 (DOY 168):

The S14 Project Briefing/Waiver Disposition meeting was held today. Members
of the Science Planning team will be generating a hand-off package for the
sequence to be given to ULO. On Monday the Science and Sequence Update
Process (SSUP) will begin.

The last commands were sent today for the S11 sequence. ULO uplinked a
relative timed Immediate/Delayed Action Program to change the CDA wall
impact detection parameter, a CAPS flight software (FSW) checkout file, and
a CAPS overlay during FSW checkout to turn the actuator off for the Radio
Science Subsystem High Gain Antenna Boresight Calibration on Tuesday of next
week. CDA team members confirmed the execution of their file, and the
sequence leads confirmed the registration and activation of the CAPS FSW
checkout program.

A member of the Mission Support and Services Office presented Cassini talks
to groups of 5th and 6th grade students at a career day at Aldama Elementary
School in Los Angeles, CA. Approximately 350 students attended. Science
Planning gave a Cassini presentation to 150 middle school girls and 50
adults for Space Pioneers in Kansas City, Missouri.

Today at approximately 5:11 PM the S12 background sequence began execution.
The sequence will run for 43.9 days ending on July 31, and will contain
Orbit Trim Maneuver #25, an Enceladus targeted flyby, solar conjunction, 6
non-targeted flybys of Titan, Tethys, Pan, Telesto, Rhea, and Epimetheus,
and will contain two occultation periods occurring on DOY 177 and 196.

Cassini achieved apoapsis today and began its tenth orbit around Saturn.

Monday, June 20 (DOY 171):

At the S12 LMB/Live IVP Go/No meeting today it was decided to proceed with
the LMB but not with the Live IVP update.

The leads for S15 received the first DSN allocation file pertaining to that
sequence. It contained no changes that would cause significant impact to
the data volume, so the decision was made to cancel the S15 Science
Allocation Panel meeting scheduled for today.

A real-time command was uplinked today for an INMS patch to FSW.

Since no new requests for waivers were generated for the S13 sequence, the
waiver disposition meeting was cancelled.

Tuesday, June 21 (DOY 172):

The S14 SSUP development process kicked off today. The files for the
Sub-Sequence Generation phase were distributed to the instrument teams,
Spacecraft Operations Office (SCO), and Navigation for review.

An image of the Cassini Crater on Earth's moon was taken by the European
Space Agency's SMART-1 spacecraft, and dedicated to the Cassini-Huygens
mission team. The occasion was the European Geoscience Union conference in
Vienna, April 2005, when new results from both missions were presented.
Saturn Observation Campaign members have shown the Cassini Crater along with
Mons Huygens on the moon to star party audiences. Here is a picture of both
lunar features:
For the full story go to:

Wednesday, June 22 (DOY 173):

Today a non-targeted flyby of Titan occurred.

An image of Saturn's rings taken with the sun on the opposite side of the
ring plane is Astronomy Picture of the Day today. From this view the rings
have similarities to a photographic negative of a front view. For example,
the dark band in the middle is actually the normally bright B-ring. The ring
brightness as recorded from different angles indicates ring thickness and
particle density of ring particles.

A delivery coordination meeting was held today for the SCO tool Flight
Software Development System (FSDS) version 2.19. FSDS is a simulation
environment for the Cassini ACS subsystem.

Wrap up:

Check out the Cassini web site at for the latest
press releases and images.

The Cassini-Huygens mission 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, manages the
Cassini-Huygens mission for NASA's Science Mission Directorate, Washington,
D.C. JPL designed, developed and assembled the Cassini orbiter.