NASA Cassini Significant Events 02/27/2013 – 03/05/2013
Cassini is orbiting Saturn with a twelve-day period in a plane inclined 57.1 degrees from the planet’s equatorial. The most recent spacecraft tracking and telemetry data were collected on March 6 by a 34-meter Deep Space Network station at Canberra, Australia. Except for some science instrument issues described in previous reports, 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/.
Commands from the on-board S77 command sequence controlled the spacecraft’s activities this week while Sequence Implementation teams continued working on the ten-week sequences S78 and S79. These will go active on the flight system on March 26 and June 7 respectively. Planning also progressed for the 2016 start of the F-ring and Proximal Orbits phase. Cassini’s next encounter will be the mission’s final targeted flyby of the 1500-kilometer diameter moon Rhea. Information about this March 9 event that will emphasize gravity science may be found on the R-4 web page: http://saturn.jpl.nasa.gov/mission/flybys/rhea20130309/
The outreach team hopes you’ll like Cassini’s official Facebook page, which is debuting this week: http://www.facebook.com/NASACassini
Wednesday, Feb. 27 (DOY 058)
The Ultraviolet Imaging Spectrograph (UVIS) observed Saturn’s northern auroral zones for a total of six hours. Following this, the Imaging Science Subsystem (ISS) carried out a Saturn “feature track”, with collaboration from the Visible and Infrared Mapping Spectrometer (VIMS), taking data at various latitudes and emission angles.
Thursday, Feb. 28 (DOY 059)
ISS observed the irregular moon Hati for six hours. Discovered in 2004, this object has a radius of about three kilometers and is in a retrograde orbit about Saturn.
Friday, March 1 (DOY 060)
The dark, four-kilometer radius irregular moon Erriapus (or Erriapo) was ISS’s target for eight hours today, followed by another eleven hours on Hati.
Orbit Trim Maneuver (OTM) 342, the maneuver targeting to the upcoming Rhea (R-4) fly-by, executed today using the main engine. The 1.6-second burn provided a delta-V of about 264 millimeters per second.
Saturday, March 2 (DOY 061)
The Cosmic Dust Analyzer (CDA) performed a fifteen-hour observation in the campaign to characterize dust that orbits Saturn in a retrograde direction.
Sunday, March 3 (DOY 062)
The Composite Infrared Spectrometer (CIRS) began a thirteen-hour Saturn observation to measure oxygen compounds (H2O, CO2) in the stratosphere.
Monday, March 4 (DOY 063)
Cassini passed through apoapsis, having coasted 1.5 million kilometers “above” the planet and slowing to 12,419 kilometers per hour relative to Saturn. This marked the beginning of Cassini’s orbit #183.
ISS performed another observation in the Satellite Orbit Campaign, looking at small satellites near Saturn; ISS and VIMS took advantage of the near-Saturn pointing to do a two-minute storm watch. ISS then started a twelve-hour low-resolution movie of the narrow F ring.
The planet Venus appears as a bright white dot amid Saturn’s rings in the image featured here: http://saturn.jpl.nasa.gov/news/newsreleases/newsrelease20130304/
Relatively fresh fractures appear as wisps on the surface of Saturn’s large icy moon Dione in this image, posted today: http://saturn.jpl.nasa.gov/photos/imagedetails/index.cfm?imageId=4746
Tuesday, March 5 (DOY 064)
After the F ring movie, ISS took two minutes for another storm watch on Saturn. CIRS then initiated a fifteen-hour observation of ring particles as their orbits carried them into Saturn’s shadow, mapping temperatures to help determine the particles’ thermal inertia.
