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Cassini Significant Events 02/22/2012 – 02/28/2012

The most recent spacecraft tracking and telemetry data in this reporting period were acquired on Feb. 29 from the Goldstone, California, Deep Space Network 34 meter Station 26. The Cassini spacecraft is in an excellent state of health. All subsystems are operating normally except for the issues being worked with the Cassini Plasma Spectrometer and the Ultrastable Oscillator. Information on the present position of the Cassini spacecraft may be found on the "Present Position" page at: http://saturn.jpl.nasa.gov/mission/presentposition/.

During Cassini's current orbit of Saturn, many observations have centered on Magnetospheric and Plasma Science (MAPS). Measurements made this week by these direct-sensing instruments included equatorial inner magnetosphere sampling, low latitude prime pointing for MAPS as the spacecraft nears apoapsis, and Cassini Apoapses for Kronian Exploration (CAKE) observations. The objective is to acquire nearly complete and continuous measurements of Saturn's outer magnetosphere and magnetosheath. By doing this once every four to six months, MAPS can sample and measure Saturn's magnetosphere over a solar cycle, from one solar minimum to the next, and investigate magnetospheric periodicities and how the Saturn kilometric radiation (SKR) period is imposed on the magnetosphere.

Wednesday, Feb. 22 (DOY 053)

The Ultraviolet Imaging Spectrograph (UVIS) and the Visual and Infrared Mapping Spectrometer (VIMS) enjoyed a period of fixed pointing at Saturn's auroral oval, then UVIS surveyed interplanetary hydrogen from its vantage point a million kilometers above Saturn's atmosphere.

An Attitude & Articulation Control Subsystem Reaction Wheel bias maneuver was executed today, setting wheel speeds as needed while thrusters maintained the spacecraft's attitude. Last week's report skipped mention of three such maneuvers during that period.

Today's Orbit Trim Maneuver 311, a cleanup maneuver for last week's Titan T-82 flyby, was canceled. Cancellation was made possible by the T-82 miss being small and in a favorable direction.

Cassini Instrument Operations Multi Mission Image Processing Laboratory (MIPL) used a downtime today to swap the database and File Exchange Interface servers to alternate hardware to continue firmware and patch updates.

Thursday, Feb. 23 (DOY 054)

Normal MIPL processing resumed.

The feature "The Many Moods of Titan" was published on the Cassini website:

The S73 command sequence developers held a Sequence Change Request (SCR) disposition meeting. Four SCRs were approved.

A Cassini-internal meeting was held today to discuss procedure and scheduling options for turning the Cassini Plasma Spectrometer (CAPS) instrument back on (recall it was turned off last June due to concerns over some problems internal to the instrument and others associated with RTG #3). Final approval will depend on the outcome of a review with JPL upper management next week.

Friday, Feb. 24 (DOY 055)

The Composite Infrared Spectrometer (CIRS), the Imaging Science Subsystem (ISS), and VIMS carried out Titan Monitoring Campaign observations to look for long term cloud activity, then VIMS and ISS conducted Saturn Storm Watch observations. The Navigation team acquired an Optical Navigation image of Enceladus with two cataloged stars in the background. It has since been processed on the ground in preparation for the March 27 flyby of Enceladus at 75 kilometer altitude.

Saturday, Feb. 25 (DOY 056)

Viewed from anywhere on Earth these days, Saturn and Titan are a delight to see in a small telescope. With good optics you might also see moons Dione, Tethys, Rhea, and even Iapetus if it happens to have enough of its bright side facing Earth. Saturn rises in the east before midnight, and is well placed for viewing in the hours before dawn, sharing the sky with bright red Mars. Find out more about this month's night sky here: http://www.jpl.nasa.gov/video/index.cfm?id=1060

Sunday, Feb. 26 (DOY 057)

During the week the Deep Space Network carried out Cassini tracking activities from all three of its worldwide complexes using 70 and 34 meter apertures, and had zero data loss. The one-way light time to Cassini is currently one hour and fifteen minutes, and is decreasing as Earth moves closer to Saturn in its orbit around the sun.

Monday, Feb. 27 (DOY 058)

The Realtime Operations team uplinked Part 2 of the S72 background sequence and verified that the spacecraft properly received and stored all 6,114 of its commands.

A unique image is featured today. "Beside a Giant" shows Titan next to Saturn, and the small F ring shepherd moon Prometheus with its shadow on Saturn, and the shadow of the other shepherd Pandora, along with shadows of the main rings and the thin F ring. View the image here:

Cassini is discussed in a PBS OpEd article as an example of international collaboration in space:

Tuesday, Feb. 28 (DOY 059)

During the week, 454 ISS images and 41 VIMS cubes were received and distributed.