From: Jet Propulsion Laboratory
Posted: Friday, February 14, 2014
Cassini is orbiting Saturn with a 31.9-day period in a plane inclined 48.1 degrees from the planet's equatorial plane. The most recent spacecraft tracking and telemetry data were obtained on Feb. 11 using the 70-meter diameter Deep Space Network (DSN) station at Canberra, Australia. Except for the science instrument issues described in previous reports (for more information search the Cassini website for CAPS and USO), 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 "Eyes on the Solar System" at http://1.usa.gov/1gwIJ9C.
Administrative staff members worked behind the scenes this week, culminating preparations for the hundred or so scientists who will visit JPL next week to attend Cassini's 62nd Project Science Group meeting. As a result, the conference room schedules, facility badging, teleconferencing setups, and many other logistics will make it easy for the science investigators to concentrate on Saturnian issues.
Wednesday, Feb. 5 (DOY 036)
The Visible and Infrared Mapping Spectrometer (VIMS) obtained two complete radial scans of the right ring ansa, parallel to the planet-shadow edge. The goal was to capture near-infrared spectra of the rings uncontaminated by Saturnshine. The other Optical Remote-Sensing (ORS) instruments also took data while VIMS controlled spacecraft pointing for about seven and one-half hours.
After the spacecraft turned and carried out a 9-hour communications session with the DSN, VIMS started a fifteen-hour observation of the narrow F ring, collecting a series of infrared spectra as a function of longitude. The Composite Infrared Spectrometer (CIRS) and the Imaging Science Subsystem (ISS) also took data in ride-along mode.
Realtime commands for Orbit Trim Maneuver (OTM)-371, the post-Titan T-98 trajectory clean up maneuver, turned Cassini and fired its small thrusters for 86 seconds today. This produced a change in velocity of 89 millimeters per second.
Thursday, Feb. 6 (DOY 037)
CIRS started an eight-hour far-infrared mapping of ring temperatures just beyond the morning edge of Saturn's shadow. ISS and VIMS rode along. The observation will aid in determining the ring-particles' thermal inertia.
Friday, Feb. 7 (DOY 038)
UVIS watched Saturn's southern aurora for eight hours while the other ORS instruments rode along.
The ISS narrow-angle and wide-angle cameras experienced a warm-start on the spacecraft today. This is a known idiosyncrasy of the instrument that occurs roughly once a year. The cameras recovered nominally and no data were lost.
Saturday, Feb. 8 (DOY 039)
The Cosmic Dust Analyzer (CDA) began a 29-hour observation of dust that orbits Saturn in the retrograde direction.
Sunday, Feb. 9 (DOY 040)
ISS began an 18-hour observation to make a movie of the D ring, which is the ring closest to Saturn. VIMS rode along. The high-phase illumination for this observation will help show off the ring's fine particles, which Cassini is planning to skirt during its proximal orbits in 2017.
Monday, Feb. 10 (DOY 041)
At JPL, the Cassini Project Science Group meeting #62 began today. Five days of team meetings, working groups, and science presentations are scheduled. There are 218 registered attendees from JPL, other NASA centers, and domestic and foreign research centers and universities.
VIMS observed the reddish star Gamma Eridani for three hours 20 minutes while it was being occulted by Saturn's rings. CIRS and ISS rode along. When this observation ended, the Cassini Navigation team used ISS to take images of Saturn's moon Iapetus for optical navigation purposes. Finally, ISS began 13 hours of high-phase observations to make a movie of particles in the Roche Division, which spans the 3,400 kilometers between the A ring and the F ring. The other ORS instruments acquired data in ride-along mode.
Saturn's F ring displays one of its many puzzles in an image featured today: http://saturn.jpl.nasa.gov/photos/imagedetails/index.cfm?imageId=4973
Tuesday, Feb. 11 (DOY 042)
With CIRS riding along, ISS began a 37-hour observation of the ring spokes while they were sunlit at a high phase angle, to make a movie and look for periodicities in the spoke-like features (http://go.usa.gov/4WGP).
This week, Cassini spent a total 44.5 hours in communication with engineers and scientists on Earth, during six sessions using DSN stations in Australia and California.
A news feature released today describes the results of NASA's campaign to study Saturn's northern and southern aurorae using observations from Cassini and the Hubble Space Telescope: http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20140211/
// end //