From: Jet Propulsion Laboratory
Posted: Friday, June 14, 2013
Cassini is orbiting Saturn with a 12-day period in a plane inclined 59.4 degrees from the planet's equatorial plane. The most recent spacecraft tracking and telemetry data were obtained on June 12 using the 70-meter diameter Deep Space Network station at Madrid, Spain. 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 and speed of the Cassini spacecraft may be found on the "Present Position" page at:
Sequence Implementation teams continued working on Cassini's ten-week command sequences S80 and S81, which will go active on the flight system on August 14 and October 22 respectively. The integrated activity plan for S82 will progress to sequencing work in early July. The S stands for Saturn Tour; during interplanetary cruise, sequences were designated C. Planning also progressed for the 2016 start of the F-ring and Proximal Orbits phase.
Wednesday, June 05 (DOY 156)
The Visible and Infrared Mapping Spectrometer (VIMS) spent most of the day making mosaics of the region in Saturn's southern hemisphere known as "storm alley" around 35 to 40 degrees latitude, with the Composite Infrared Spectrometer (CIRS) riding along to make thermal measurements. Of course all the Optical Remote-Sensing (ORS) instruments are rigidly mounted, so as the spacecraft turns to point one of them, all see the same target. "Riding along" means room has been allocated for the other instrument's data on Cassini's solid-state recorders, and that the instrument is executing commands internally to make observations and produce data.
Complex hydrocarbon-ring molecules in Titan's upper atmosphere that evolve into its orange-brown haze are subjects of the illustrated news feature released today:
Thursday, June 06 (DOY 157)
CIRS conducted compositional mapping to measure trace gases and isotopes in Saturn's atmosphere around storm alley, with the Ultraviolet Imaging Spectrograph (UVIS) riding along. This was the last science observation in the ten-week command sequence S78.
Friday, June 07 (DOY 158)
As the S79 commands began their 68-day control of the spacecraft, the Magnetospheric and Plasma Science (MAPS) teams began an outer magnetospheric and dust survey campaign. VIMS obtained mosaics of Saturn's southern hemisphere for a movie, while the Imaging Science Subsystem (ISS) and the other ORS instruments UVIS and CIRS rode along. The spacecraft traversed apoapsis having coasted about 1.4 million kilometers "uphill" from Saturn, slowing to 15,154 kilometers per hour relative to the planet.
Saturday, June 08 (DOY 159)
Commands for the next Orbit Trim Maneuver, OTM-351, were processed, reviewed, approved, and uplinked today, timed for execution on Tuesday. Meanwhile, VIMS took more mosaics for the south pole movie while CIRS rode along.
Sunday, June 08 (DOY 160)
The Radio Science team performed an operations readiness test with one of the 34-meter Deep Space Network (DSN) stations in Australia to demonstrate preparedness to support the Saturn rings occultation experiment coming up on June 24. This DSN pass was one of six communications and tracking sessions with Cassini during the week.
VIMS conducted mapping of Saturn's south polar aurora with the other ORS instruments riding along, then UVIS took control of spacecraft pointing, to image the aurora with a series of rapid slews. VIMS rode along.
Monday, June 10 (DOY 161)
ISS led the ORS teams with a distant observation of Titan's haze as part of the ongoing Titan monitoring campaign. VIMS then watched the red star R Cassiopeia as it was occulted by the F-ring and the A-ring, CIRS riding. Finally, CIRS imaged Saturn's southern aurora by staring at one location to derive composition, while UVIS and VIMS also took data.
A good view of Saturn's innermost ring, the faint and still fairly mysterious D ring, is the subject of an image featured today. Later in the mission, the periapse of Cassini's "proximal" orbits will come between this ring and Saturn's atmosphere:
Tuesday, June 11 (DOY 162)
OTM 351, targeting the Titan T92 close encounter on July 10, executed today using Cassini's 400-newton main engine. The 4.7-second burn provided Cassini a change in velocity of 817 millimeters per second. With periapsis only two days away, Saturn's inner magnetosphere became the subject of the MAPS instruments' survey.
Visit the JPL Cassini home page for more information about the
Cassini Project: http://saturn.jpl.nasa.gov/
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