News | July 2, 2013
Cassini Significant Events 06/26/2013 - 07/02/2013
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 early on July 1 using one of the 34-meter diameter Deep Space Network stations 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: http://saturn.jpl.nasa.gov/mission/presentposition/.
Sequence Implementation teams continued working on Cassini's ten-week command sequences S80 and S81, which will go active on the flight system on Aug. 14 and Oct. 22 respectively. The integrated activity plan for S82 has been in work as well. Planning also progressed for the 2016 start of the F-ring and Proximal Orbits phase.
Wednesday, June 26 (DOY 177)
A long movie of Saturn’s northern polar regions, designed to capture the complex atmospheric dynamics at work and led by the Visible and Infrared Mapping Spectrometer (VIMS), occupied Cassini for most of the day. Following this, the Imaging Science Subsystem (ISS) made a Titan Monitoring Campaign observation.
Thursday, June 27 (DOY 178)
Early in the planning process for spacecraft commanding are high-priority opportunities that enjoy early placement in the sequences; other science and engineering activities are then worked in around them. Two such Pre-Integrated Events, affectionately known to the science planners as PIEs, executed today, with the Ultraviolet Imaging Spectrograph (UVIS) leading the rest of the optical remote-sensing instruments to make low-phase observations of Saturn's moons Dione and Mimas. Observing these moons when the surface is fully illuminated is useful for understanding the surfaces' texture and other properties; the ultraviolet observations are especially significant for understanding surface composition. The day concludes with ISS staring again at Saturn's northern hemisphere.
You can now access a "Wave at Saturn" banner in many languages (some of them tongue-in-cheek) for your website or bulletin board: http://saturn.jpl.nasa.gov/news/waveatsaturn/resources. Be sure to note the time of day for your location on July 19 when light reflected from Earth will begin its trip to the open shutters of Cassini's cameras: http://saturn.jpl.nasa.gov/news/waveatsaturn/timezone.
Friday, June 28 (DOY 179)
ISS observed Mimas transiting the face of first Enceladus and then smaller Pandora. ISS made an observation in the Satellite Orbit Campaign today and again on Tuesday, looking at small known objects near Saturn, and possibly discovering more of them. ISS then watched the transit of Enceladus across Calypso. After VIMS squeezed in a two-minute Saturn storm-watch observation, the day concluded with a four-hour ISS observation of Saturn's innermost ring, the D-Ring, close in and at low phase illumination.
Saturday, June 29 (DOY 180)
The Composite Infrared Spectrometer (CIRS) mapped Saturn for ten hours in the mid-infrared to determine temperatures in the upper troposphere and the tropopause. ISS then observed the irregular moon Ijiraq, for nine hours today and 19.5 hours on Sunday. This body, named after a figure in Inuit mythology, has a very dark surface, is about ten kilometers in diameter, and orbits more than eleven million kilometers from Saturn.
Sunday, June 30 (DOY 181)
Is it a sponge or an icy moon? Today's Astronomy Picture of the Day features Cassini's close-up view of Saturn's 250-kilometer-long moon Hyperion, which, thanks to Cassini Radio Science measurements in September 2005, is known to have an average density about halfway between frozen water and empty space: http://apod.nasa.gov/apod/ap130630.html
Monday, July 1 (DOY 182)
In local Pacific Time, today marks the ninth anniversary of Cassini's successful Saturn Orbit Insertion. Annotated diagrams recount the critical operations of July 1, 2004 on this page: http://www.jpl.nasa.gov/basics/soi/
The spacecraft glided through apoapsis having slowed to 14,671 kilometers per hour relative to Saturn, about 1.4 million kilometers from the planet. This marked the start of Saturn orbit #194.
ISS performed a thirteen-hour observation of the G ring arc at low phase, and then began a sixteen-hour low-resolution movie of the F ring. An image featured today shows the small lumpy moon Janus, which orbits Saturn just outside the narrow F ring: /resources/15834
Tuesday, July 2 (DOY 183)
CIRS observed the rings for six hours to gather data on thermal energy transport between the lit and unlit sides.