News | November 20, 2014
Cassini Significant Events 11/12/2014 - 11/18/2014
Cassini is currently orbiting Saturn with a 47.8-day period in a plane inclined 33.1 degrees from the planet's equatorial plane. The most recent spacecraft tracking and telemetry data were obtained on November 19 using one of the 34-meter diameter Deep Space Network (DSN) 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. Information on the present position of the Cassini spacecraft may be found on "Eyes on the Solar System".
While Cassini lingered near its greatest distance from Saturn in the current orbit, the 10-week command sequence S86 controlled activities from onboard memory. As the spacecraft neared superior conjunction, the level of on-board activities slowed. (During superior conjunction, Cassini’s radio signal passes very near the sun, which limits the data playback rate.) Meanwhile back on Earth, sequence implementation teams worked on developing the command sequences S87, S88, and S89, while work proceeded on activities for the Grand Finale Mission events of 2017.
Note that the Cassini Significant Events will not be issued during the week of Thanksgiving (a national holiday in the U.S.).
Wednesday, Nov. 12 (DOY 316)
The Cosmic Dust Analyzer (CDA) completed a 36-hour long direct-sensing observation of dust that orbits Saturn in the retrograde dust direction.
Today happens to be the anniversary of Voyager-1's groundbreaking, fast-flyby encounter with Saturn in 1980.
Thursday, Nov. 13 (DOY 317)
CDA began another observation of retrograde dust; this one lasted 33 hours.
Friday, Nov. 14 (DOY 318)
Cassini coasted through apoapsis late in the day today, marking the start of its Saturn orbit #210. The spacecraft had reached a distance of 4.4 million kilometers, and slowed to 5,367 kilometers per hour relative to the planet. Cassini then began gaining speed for its 24-day long plunge toward periapsis.
Saturday, Nov. 15 (DOY 319)
The spacecraft turned to keep the high-gain antenna dish pointing to Earth for several days, and switched to the small rocket thrusters for attitude control; this will relax demands on Cassini's reaction wheels for a few days while passing around the far side of the Sun as seen from Earth. While Cassini's primary axis pointed to Earth, its secondary axis was chosen to best suit the Magnetospheric and Plasma Science (MAPS) instruments in an effort to obtain additional magnetotail data.
Sunday, Nov. 16 (DOY 320)
With Cassini remaining Earth-pointed, the Radio Science team utilized its downlink signals to probe the Sun's corona at different frequencies, assessing the electron content and possible Faraday rotation.
Monday, Nov. 17 (DOY 321)
An image featured today uses the Imaging Science Subsystem's red filter to show some of Saturn's amazing cloud features:
NASA's Image of the Day included this one, as well as other images from Cassini this week: http://www.nasa.gov/multimedia/imagegallery/iotd.html
A member of Cassini's Realtime Operations team gave a presentation tonight about Cassini's 20-year mission to an enthusiastic audience at the Griffith Observatory in Los Angeles.
Tuesday, Nov. 18 (DOY 322)
Today Saturn, and Cassini, aligned with the Sun to mark the moment of superior conjunction. Its angular distance from the Sun's center, as viewed form Earth, was 2.02 degrees to the north (the Sun's apparent diameter is 0.5 degrees).
This week, the DSN communicated with and tracked Cassini on four occasions, using stations in Australia. Each also participated in Cassini's Radio Science superior conjunction experiment. A total of four individual commands were uplinked, and about 870 megabytes of telemetry data were downlinked and captured at rates as high as 110,601 bits per second.