Cassini Significant Events 01/30/2013 - 02/05/2013 Cassini is orbiting Saturn with a period of 13.3 days in a plane inclined 53 degrees from the planet's equatorial. The most recent spacecraft tracking and telemetry data were collected on Feb. 5 by the 70 meter Deep Space Network station at Goldstone, California. Except for some science instrument issues described in previous reports, the spacecraft continues to be in an excellent state of health with all of its subsystems operating normally. 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/. This week's science observations were largely about the rings as Cassini sped through the close-in part of its orbit. Methods included passive optical remote sensing plus the active remote sensing technique of a Radio Science occultation experiment. Also this week, the spacecraft executed its first Orbit Trim Maneuver (OTM) since the beginning of December 2012. Wednesday, Jan. 30 (DOY 030) The Composite Infrared Spectrometer (CIRS) mapped ring temperatures in Saturn's shadow to measure thermal inertia. The Visible and Infrared Mapping Spectrometer (VIMS) then performed a four hour observation of the star R Cassiopeiae while it was occulted by the rings. OTM 339, the propulsive maneuver targeting to the Titan T-89 encounter coming up on Feb. 17, executed today. The 9.5 second main engine burn provided Cassini a delta-V of about 1.7 meters per second. Thursday, Jan. 31 (DOY 031) The Radio Sicence team carried out a six hour occultation experiment similar to the shorter one conducted on Jan. 18. This time though, the experiment also included observing the spacecraft's egress from behind Saturn as the spacecraft's three radio-frequency signals probed the upper troposphere and ionosphere on the way out. Following the Radio Science experiment, the Cosmic Dust Analyzer took control of spacecraft pointing and acquired data for four hours while the spacecraft ascended through Saturn's ring plane at an altitude of about 440,000 kilometers. Near the end of the day, the Imaging Science Subsystem (ISS) began a unique 17 hour survey of the "propeller belts" in the mid A ring, known to have swarms of small propellers. This area has never been systematically searched for individually trackable "giant propellers" such as the one seen here: http://go.usa.gov/YyGR An article on the massive storm that wrapped itself around Saturn last year was featured today. It may be seen here: http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20130131/ Friday, Feb. 1 (DOY 032) Cassini passed through periapsis going 41,678 kilometers per hour relative to Saturn at an altitude of about 388,000 kilometers. After periapsis, ISS observed the F ring at high resolution for four hours to study the time-variable small-scale structure in the core of the narrow ring; the resolution of this observation is about three times better than in most F ring observations. CIRS then started a seven hour radial scan of the rings to help model their directional emissivity. Saturday, Feb. 2 (DOY 033) VIMS observed an ingress occultation of the star W Hydrae as it made a radial pass across the ring system. CIRS then performed another radial scan of the rings. Late in the day ISS began an eleven hour movie focusing on the outer edge of the B ring to study edge modes and interactions between the rings and satellites. Sunday, Feb. 3 (DOY 034) ISS made a 2.5 hour observation of the D ring at low phase angles, monitoring its time-variable structures including corrugation in its outer region. Finally, ISS began 20.5 hour observation of the irregular moon Erriapus in its prograde Saturn orbit over 17.3 million kilometers away. A 34 meter Deep Space Network station in Australia participated in an operations readiness test in preparation for the Radio Science Titan gravity science experiment coming up on Feb. 17. Monday, Feb. 4 (DOY 035) ISS made an observation in the satellite orbit campaign and then took five images of Saturn's satellite Hyperion against background stars for optical navigation. ISS then began a seven hour D-Ring observation. A feature describing the behavior of aerosols in Titan's atmosphere was published today: http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20130204/ The puzzling hexagonal atmospheric feature in Saturn's northern hemisphere is seen in beautiful detail in an image featured today: http://saturn.jpl.nasa.gov/photos/imagedetails/index.cfm?imageId=4736 Tuesday Feb. 5 (DOY 036) After one more satellite orbit observation, ISS began imaging the G-ring moon Aegeaon for 21 hours at low phase illumination. ------------------------ To unsubscribe from Cassini Spacecraft Updates or to subscribe with a different email address, visit here: http://saturn.jpl.nasa.gov/news/mailinglistsignup/ ------------------------ This email address is not monitored. For comments and questions, please contact Cassini Outreach here: http://saturn.jpl.nasa.gov/feedback/ ------------------------ Visit the JPL Cassini home page for more information about the Cassini Project: ------------------------ |
