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Cassini Significant Events 06/03/09 – 06/09/09

The most recent spacecraft telemetry was acquired on June 9 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, June 3 (DOY 154)

Science observations for today were few, but ran for long durations.
Imaging Science (ISS) observed the rotation light curve for Kiviuq, one of the satellites of Saturn, for 10h34m. The Ultraviolet Imaging Spectrograph (UVIS) then mosaicked Saturn¹s magnetosphere for 8h, and the Magnetometer (MAG) performed a regularly scheduled instrument calibration for 5h40m.

Friday, June 5 (DOY 156)

Late this evening Uplink Operations sent six Instrument Expanded Block (IEB) files to the spacecraft in support of S51. The remaining three IEBs will go up late Sunday evening, and the background sequence will be transmitted Wednesday of next week. S51 begins execution on Friday, June 12.

Saturday, June 6 (DOY 157):

Today Cassini passed Titan for the T56 flyby with closest approach at approximately 6:02 PM PDT, traveling at 6 km/sec, an altitude of 968 km, and latitude 32.1 degrees S. T56 provided the only dusk side observations at mid-southern latitudes, and the Ion and Neutral Mass Spectrometer (INMS) took advantage of that, riding along with RADAR at closest approach. It is also the only time in the mission when the spacecraft will obtain simultaneous coverage of the dusk side while in the wake magnetospheric interaction region.

The RADAR instrument captured synthetic aperture RADAR (SAR), outbound altimetry, scatterometry, and radiometry data during this flyby. The SAR swath ran parallel to, and partly overlapped, the swath captured in T55, over Tortola Facula, 'the snail', and down through Shangri-La to high southern latitudes.

The Composite Infrared Spectrometer (CIRS) measured distant stratospheric composition and performed temperature mapping to search for seasonal changes, and the Magnetospheric Imaging Instrument (MIMI) measured energetic ion and electron energy input to Titan¹s atmosphere.

The Visual and Infrared Mapping Spectrometer (VIMS) rode along with UVIS for a stellar occultation that will provide information on the composition of Titan's atmosphere, then rode along with UVIS and CIRS to observe the south polar region.

ISS rode along with VIMS to observe eastern Tsegihi and to monitor clouds over Titan's trailing hemisphere at mid-southern latitudes.

UVIS observations at T56 were part of an ongoing sequence to acquire latitude, phase angle, and time coverage of atmospheric composition, including Titan¹s haze. UVIS is a box of four telescopes that can see ultraviolet light. There are three slits each on the Extreme Ultraviolet
(EUV) and Far Ultraviolet (FUV) telescopes that allow light into the instrument to be measured. This particular flyby included a stellar occultation and an EUV/FUV image. The instrument obtained an image 'cube' of Titan's atmosphere at EUV and FUV wavelengths by sweeping the slit across the disk. These cubes provide spectral and spatial information on nitrogen emissions, H emission and absorption, absorption by simple hydrocarbons, and the scattering properties of haze aerosols. This is one of many such cubes gathered over the course of the mission to provide latitude and seasonal coverage of Titan's middle atmosphere and stratosphere.

As in T55, measurements at T56 by the Magnetometer (MAG) provided a description of the draping and the pileup of the external magnetic field around Titan on the night side hemisphere. It also complemented data obtained at T52, T53, T54 and T55 in order to characterize the background field for a similar local time with respect to Saturn and different Saturn Kilometric Radiation longitudes

Finally, the Radio and Plasma Wave Science instrument measured thermal plasmas in Titan's ionosphere and surrounding environment, searched for lightning in Titan's atmosphere, and investigated the interaction of Titan with Saturn's magnetosphere.

For more information on the T56 encounter, link to:

An AACS Periodic Engineering Maintenance activity occurred today. Performed every 90 days, this activity exercised the main engine gimbal actuators and the Reaction Wheel Assembly (RWA) backup wheel RWA-3. For the RWA wheel, it was commanded to +100 rpm, -100 rpm, 0 rpm, then turned back off.

Monday, June 8 (DOY 159):

Members of the Cassini Outreach team accepted a 2009 Webby Award for Best Science website from the International Academy of Digital Arts and Sciences.
For more information on this award link to:

All participating teams submitted files today for the second input port as part of the S54 Science Operations Plan process.

Today was the birthday of Giovanni Domenico Cassini, born in 1625. Cassini, namesake of the Cassini orbiter, discovered four moons of Saturn and the large gap in Saturn's rings, now called the Cassini division. For more information link to:

Tuesday, June 9 (DOY 160)

Once a year, NASA honors individuals and groups for managerial and technical excellence, and outstanding performance on demanding projects during the year. At a ceremony on the JPL mall today celebrating the 2009 NASA Honor Awards, the following nineteen Cassini teams were recognized with group achievement awards for their support of the Cassini Saturn Prime Mission:

Composite Infrared Spectrometer Team
Cosmic Dust Analyzer Team
Cross-Discipline Target Working Team
Imaging Science Team
Interdisciplinary Scientist Team
Ion and Neutral Mass Spectrometer Team
Magnetometer Team
Magnetospheric Target Working Team
Magnetospheric Imaging Instrument Team
Plasma Spectrometer Team
Radio and Plasma Wave Science Team
Radio Science Team
Rings Target Working Team
Satellite Orbiter Science Team
Saturn Target Working Team
Saturn Tour Flight Team
Titan Orbiter Science Team
Ultraviolet Imaging Spectrograph Team
Visual and Infrared Mapping Spectrometer Team

In addition, twelve past and current members of the Cassini Flight Team were awarded individual medals in recognition of their contributions to the Cassini Project.