From: Jet Propulsion Laboratory
Posted: Sunday, October 20, 2013
Cassini is orbiting Saturn with a 31.9-day period in a plane inclined 51.9 degrees from the planet's equatorial plane. The most recent spacecraft tracking and telemetry data were obtained on Oct. 2 using the 70-meter diameter Deep Space Network station at Canberra, Australia. Except for some 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 the "Present Position" page at:
Some of the inclined orbits in this part of Cassini's Saturnian tour were designed to provide passage through Saturn's magnetotail. While the direct-sensing Magnetospheric and Plasma Science (MAPS) instruments continued gathering data as usual, they were able to characterize a magnetotail crossing over the course of a few days. An artist's conception here http://saturn.jpl.nasa.gov/photos/imagedetails/index.cfm?imageId=2881 sets the stage to visualize the spacecraft's location in this magnetic region; picture Cassini about twice the distance from Saturn as is Titan, whose location is shown to scale in the image, and downstream from the planet in the direction away from the Sun (that is, toward the left of the image).
Wednesday, Sept. 25 (DOY 268)
Cassini coasted into the magnetotail today. Back on Earth, representatives of the Flight team and JPL Facilities met to determine the logistics of moving the Cassini Mission Controllers, who are members of the Realtime Operations team, back into the publicly viewable area on the first floor of the Space Flight Operations Facility, known locally as "the darkroom." The target for completion is Nov. 8 while realtime activities are at a minimum during superior conjunction. The team operated in the darkroom during launch in October of 1997, but has occupied a dedicated, third-floor operations console ever since.
Thursday, Sept. 26 (DOY 269)
The Imaging Science Subsystem (ISS) began an observation lasting early twenty hours to see the edge of Saturn's shadow on the Phoebe ring. Discovered in 2009 by the Spitzer Space Telescope, this enormous ring orbits Saturn nearly 13 million kilometers out. It is likely composed of particles ejected during micrometeoroid impacts on the small moon Phoebe, which orbits the planet in a retrograde direction along with its ring particles.
Friday, Sept. 27 (DOY 270)
The Composite Infrared Spectrometer (CIRS) spent eight hours today doing a calibration of stray light by monitoring scattered infrared solar radiation as a function of offset angle from the Sun using radial scans. During the calibration, and having slowed to 10,625 kilometers per hour while coasting "up" from Saturn, Cassini passed though apoapsis at 2.68 million kilometers from Saturn, more than twice the distance from the planet to Titan's orbit. This marked the start of Saturn Orbit #198.
Saturday, Sept. 28 (DOY 271)
A news feature and video released this week announces Cassini's finding evidence of the hydrocarbon propylene, a new piece of the "chemical-zoo" puzzle that makes up Titan's atmosphere:
Sunday, Sept. 29 (DOY 272)
The Cosmic Dust Analyzer (CDA) measured interstellar dust for fifteen hours. The day concluded with execution of Orbit Trim Maneuver (OTM) 360, which turned the spacecraft and fired the rocket thrusters for 66 seconds to provide Cassini a change in velocity of 69 millimeters per second. Performed near apoapsis, this was a targeting maneuver for the Titan T-95 fly-by coming up on Oct. 14.
Monday, Sept. 30 (DOY 273)
The Ultraviolet Imaging Spectrograph (UVIS) performed a fifteen-hour mosaic scan as part of the magnetosphere observing campaign. Rings and waves and the little moon Daphnis star in an image featured today:
Tuesday Oct. 1 (DOY 274) UVIS began another mosaic scan of Saturn's magnetosphere; this one will take thirty-seven and a quarter hours to complete.
Visit the JPL Cassini home page for more information about the Cassini Project: http://saturn.jpl.nasa.gov/
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