Cassini Significant Events 01/21/2015 – 01/27/2015

Cassini is currently orbiting Saturn with a 31.9-day period in a plane inclined 19.1 degrees from the planet's equatorial plane. The most recent spacecraft tracking and telemetry data were obtained on Jan. 27 using one of the 34-meter diameter Deep Space Network stations in Australia. The spacecraft continues to be in an excellent state of health with all of its subsystems operating normally except for the instrument issues described at
http://saturn.jpl.nasa.gov/news/significantevents/anomalies .

This week, Cassini scientists, engineers, and managers met at the 65th Project Science Group meeting held at the Italian Space Agency headquarters in Tor Vergata, near Rome. One major emphasis of the meeting was Titan. Two half-day workshops covered the vast range of science results on this unique body which Cassini and Huygens both began studying in detail over 10 years ago. In commemoration of its 10th anniversary since landing (Jan. 14, 2005), the first session was devoted to results from the Huygens probe. The second session was devoted to results from the Cassini spacecraft instruments.

Another major topic was the allocation of periapsis passes to the science instruments during the Grand Finale. There are only 22 periapses in this phase where the spacecraft passes between the planet and its rings. These are precious opportunities and the scientists and planning engineers have worked out some clever techniques that allow several instruments to “share” the same spacecraft configuration; this is much the same way ride-along observations are performed now but this time with the in-situ instruments, radar, and radio science. The team is very close to settling on the final allocations for this very important mission phase.

Wednesday, Jan. 21 (DOY 021)

The Composite Infrared Spectrometer (CIRS) finished a 10-hour stare at Saturn's sunlit A ring that began the previous day, obtaining thermal infrared spectra to study the ring particles' composition. The Imaging Science Subsystem (ISS), and the Visible and Infrared Mapping Spectrometer (VIMS), rode along to make their own A-ring observations. Next, ISS directed spacecraft pointing so it could make a two-minute storm-watch observation on Saturn.

With yet another year of exploration and discovery successfully completed, the Cassini scientists' picks for the top 10 highlights and the top 10 images of 2014 have been published:
http://saturn.jpl.nasa.gov/news/cassinifeatures/topscience2014/ and http://saturn.jpl.nasa.gov/news/cassinifeatures/topimages2014/ .

Thursday, Jan. 22 (DOY 022)

After playing back data from the Solid State Recorders (SSR) over Deep Space Network (DSN) stations at Goldstone and Canberra, the spacecraft remained with its high-gain antenna pointed to Earth to let the Magnetospheric and Plasma Science instruments continue sensing the spacecraft's immediate environment.

Friday, Jan. 23 (DOY 023)

CIRS stared at the sunlit B ring for 10 hours today, studying ring particle composition. The same observation repeated the next day for nine hours. VIMS rode along for both of these. The B ring is the middle one of Saturn's three main rings easily visible from Earth.

Saturday, Jan. 24 (DOY 024)

Since Approach Science began early in 2004, there have been 332,564 ISS images and 220,903 VIMS cubes acquired, transmitted to Earth, and processed.

Sunday, Jan. 25 (DOY 025)

Cassini marked the start of its Saturn orbit #212 by passing through apoapsis today. It had gradually slowed to 5,514 kilometers per hour relative to the planet, and reached an altitude of 3.46 million kilometers. It's all "downhill" from here to the next periapsis, on Feb. 12.

Monday, Jan. 26 (DOY 026)

CIRS observed Saturn for 12 hours to better determine its atmospheric composition. All the other optical remote-sensing instruments -- ISS, VIMS, and the Ultraviolet Imaging Spectrograph (UVIS) -- used their telescopes to acquire data in ride-along mode. ISS performed an observation in the satellite orbit campaign, looking near Saturn for small objects. In between these two observations, and then again twice afterwards, ISS took the opportunity to make two-minute Saturn storm-watch observations. VIMS participated in two of the three.

With these observations complete, ISS began 13 hours of tracking and imaging the distant, irregular moon Siarnaq. Named after a giant in Inuit mythology, at about 32 kilometers in diameter, this very dark-surfaced body is the largest member of the Inuit group of Saturn's irregular satellites. Its inclined orbit reaches 17.5 million kilometers from the planet.

The tiny satellite Pandora makes its colossal trip all the way around Saturn once every 15.1 hours. It can be seen outside of the narrow, bright F ring in an image featured today, along with some interesting details visible in the outer part of the A ring:
/resources/16143 .

Tuesday, Jan. 27 (DOY 027)

The Cosmic Dust Analyzer (CDA) began a series of observations as part of the exogenous dust campaign, collecting and characterizing dust that originates outside the Saturn system. Today's lasted nine hours.

During the past week, the DSN communicated with and tracked Cassini on nine occasions, using stations in Canberra, Australia and Goldstone, California. A total of 10 individual commands were uplinked, and about 1,082 megabytes of telemetry data were downlinked and captured at rates as high as 124,426 bits per second.