Cassini Update - February 26, 2010

[baa...@earthlink.net]

Cassini Significant Events
for 02/17/10 - 02/23/10

The most recent spacecraft telemetry was acquired on Feb. 23 from the
Deep Space Network tracking complex at Canberra, Australia. 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:
http://saturn.jpl.nasa.gov/mission/presentposition/ .

Wednesday, Feb. 17 (DOY 048)

An encounter strategy meeting was held today to cover the period
between Mar. 2 and Apr. 6, the Rhea 2 and Dione 2 flybys, and
maneuvers 239-241.

Saturn's moon Calypso was Astronomy Picture of the Day today. Check
it out here::
http://antwrp.gsfc.nasa.gov/apod/ap100217.html

Science this week included a Visual and Infrared Mapping Spectrometer
global dynamics mosaic of Saturn's equator, a Magnetometer
calibration, and a Radio Science boresight calibration. Imaging
Science (ISS) took multiple images of Iapetus, and observed the
clouds of Titan. The Composite Infrared Spectrometer (CIRS) created a
mid-infrared thermal map of Saturn to determine upper troposphere and
tropopause temperature, and measured oxygen compounds in Saturn's
stratosphere. The Cassini Plasma Spectrometer spent approximately
17.5 hrs participating in a Magnetospheric and Plasma Science survey.

The Exhibit "400 Years of Discovery: From Galileo to the Outer
Planets" commemorating the anniversary of Galileo's discovery and
highlighting the exploration of the Outer Solar System including
Cassini will debut at the 41st Lunar and Planetary Science
Conference, The Woodlands, Texas, March 1-5, 2010. The resident
Cassini EPO astronomer has done a special related podcast that
students and the public can download for free on iTunes. It is
available at
http://solarsystem.nasa.gov/news/whatsup-view.cfm?WUID=304,
under What's Up For February - 400th Anniversary of Galilean Moon
discovery, which includes NASA educational content and a two page
flier on Galileo. The NASA/Itunes link is here:
http://www.nasa.gov/multimedia/podcasting/whatsup_index.html

Wired Magazine, one of Cassini's Webby competitors for best science
website, admitted they love one of "our" moons. "Enceladus has to be
one of the most intriguing objects in the solar system. It's
definitely our favorite of Saturn's 62 moons here at Wired Science."
http://www.wired.com/wiredscience/2010/02/gallery-enceladus/
The Wired piece was most likely a direct descendant of Cassini's
Science League feature.

Thursday, Feb. 18 (DOY 049)

An AACS Periodic Engineering Maintenance (PEM) activity occurred
today. Performed approximately every 90 days, the PEM exercises a
combination of the Engine Gimbal Actuators and the backup Reaction
Wheel Assembly (RWA).

Uplink Operations sent real time commands to the spacecraft today to
perform a CIRS noise test. The files patched the CIRS flight software
to perform the noise test, and then took data during a deep space
calibration observation and a Saturn CompSit prime observation. At
the end of the observations the patch returned the instrument state
to the current flight software version. The activity ran from
051T21:33:00 to 053T04:49:05. The purpose of the patch is to see if
changes in the software can eliminate internal instrument generated noise.

Friday, Feb. 19 (DOY 050)

A 3-D image of the Saturnian moon Prometheus has been posted to the
Cassini Web page. The news note that goes with this image called
"Behold the Violent History of Saturn's White Whale Moon" explains
that this view, which resembles the white whale Moby Dick, exposes
the irregular shape and circular surface scars on Prometheus,
pointing to a violent history. This image looks different from the
"egg-cellent" raw image of Prometheus obtained on Jan. 27 because
that view shows one of the short ends of the oddly shaped moon. In
this image, the sun illuminates Prometheus at a different angle,
making the moon's elongated body visible.
http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20100219/

Monday, Feb. 22 (DOY 053):

All teams submitted Port 3 files for S60 and Port 2 files for S61 as
part of two Science Operations Plan processes. Each set of files will
be merged tomorrow and then sent back out to the teams for review.

Uplink Operations (ULO) radiated 14 Instrument Expanded Block files
to the spacecraft today in support of sequence S58. The background
sequence will go up Friday, and the sequence will begin execution on
Monday, Mar. 1.

ULO has received an absolute timed real-time command file from the
Cosmic Dust Analyzer instrument team. Starting on DOY-061T16:00, the
commands will customize the instrument's visibility to bigger
particles during the upcoming Rhea flyby on Mar. 2 and the following
periapse passage. The command approval meeting for this file is
scheduled for Thursday, Feb. 25.

Tuesday, Feb. 23 (DOY 054)

The monthly Cassini-Huygens Analysis and Results of the Mission
(CHARM) teleconference for February was held today. The topic: Boom
and Bust Cycles in Saturn's Rings. The presentation package is now on
line here:
http://saturn.jpl.nasa.gov/video/products/MultimediaProductsCharm/

Orbit Trim Maneuver (OTM) #237 was performed today. This was the
apoapsis maneuver setting up for the Rhea 2 encounter on March 2. The
Reaction Control Subsystem burn began at 9:44 AM. Telemetry
immediately after the maneuver showed a burn duration of 8.75
seconds, giving a delta-V of 15.24 mm/s. All subsystems reported
nominal performance after the maneuver.

Newly released images from last November's flyby of Enceladus
revealed a forest of new jets spraying from prominent fractures
crossing the south polar region, and yielded the most detailed
temperature map to date of one fracture. The new images also include
the best 3-D image ever obtained of a "tiger stripe," and views of
regions not well mapped previously on Enceladus, including a southern
area with crudely circular tectonic patterns. For the full story and
images link to the following:
http://saturn.jpl.nasa.gov/news/newsreleases/newsrelease20100223/

Visit the JPL Cassini home page for more information about the
Cassini Project:
http://saturn.jpl.nasa.gov/>
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