Cassini Significant Events 05/04/11 – 05/10/11

The most recent spacecraft telemetry was acquired on May 10 from the Deep Space Network tracking complex at Goldstone, California. The Cassini spacecraft is in an excellent state of health and all subsystems are operating normally. Information on the present position and speed of the Cassini spacecraft may be found on the "Present Position" page at: http://saturn.jpl.nasa.gov/mission/presentposition/.

Wednesday, May 4 (DOY 124)

The Cassini Outreach team to date has provided 194 teachers and 15,042 students in 43 states with Cassini Education and Public Outreach (E/PO) materials through the DonorsChoose project, an online charity that makes it easy to help students in need through school donations.

Thursday, May 5 (DOY 125)

An encounter strategy meeting was held today to cover the period between May 8 and June 20, Titan flybys T-76 and T-77, and maneuvers 284-286.

Orbit Trim Maneuver (OTM) #283 was performed today. This was the approach maneuver setting up for the Titan 76 encounter on May 9. The Reaction Control Subsystem (RCS) burn began at 4:30 PM PDT. Telemetry immediately after the maneuver showed a burn duration of 8.125 seconds, giving a delta-V of 0.0143 m/s. All subsystems reported nominal performance after the maneuver.

An article called “On Titan, the Sky is Falling” was posted on the Cassini web site today. It describes how the haze is falling on Titan, according to researchers working on the Cassini mission. A haze layer covering most of Titan has dropped in altitude from 500 kilometers above Titan's surface to 380 kilometers during the years spanning 2007 to 2010. The timing of this meteorological shift implicates Titan's seasonal change. This is another indication that Titan is a dynamic world, like our own. Titan can teach us more about weather and seasonal changes on Earth, Mars, and elsewhere in the Solar System. For more information on this subject, link to: http://saturn.jpl.nasa.gov/news/cassiniscienceleague/science20110505/.

Saturday, May 7 (DOY 127)

A Cassini Outreach proposal to present a workshop on "Reading, Writing & Rings" has been accepted at the 2011 California Science Education Conference in Pasadena, CA. The conference will be held on October 21-23, 2011.

Sunday, May 8 (DOY 128)

Cassini encountered Titan (T-76) today at an altitude of 1,873 kilometers and a speed of 5.9 km/sec. Closest approach occurred at 22:53:45SCET at a latitude of 0.0°. This was a post-dusk, upstream equatorial flyby, similar to the prime mission T-34 flyby. During this flyby, the visible and infrared mapping spectrometer (VIMS) acquired high resolution images of Belet and the surrounding dune fields. The imaging science subsystem (ISS) rode along with VIMS to acquire high-resolution images at low phase angle. VIMS also continued its mapping of the cloud coverage in order to detect any seasonal changes in the cloud distribution before and after the equinox. ISS did ride-along observations with VIMS as it acquired regional- and global-scale observations of Titan's trailing/anti-Saturnian hemisphere, including western Belet and Senkyo. While VIMS, UVIS and CIRS performed atmospheric and surface measurements for 19+ hours during the outbound portion of the flyby, ISS monitored Titan's haze and clouds.

Monday, May 9 (DOY 129)

This week in science, CIRS performed a 23-hour observation to map Saturn in the mid-infrared (mid-IR) in order to determine upper troposphere and tropopause temperatures; later CIRS observed Saturn for 12 hours in order to measure oxygen compounds in the stratosphere. ISS performed a 12 hour calibration using the star Vega, and then performed an observation in its Satellite Orbit Campaign, this time observing Methone, Janus, Polydeuces, Telesto, Prometheus, Pandora and Calypso. After the Titan flyby, UVIS kicked off the periapsis segment with a northern Saturn auroral movie, in which the other Optical Remote Sensing (ORS) instruments participated and during which the Cosmic Dust Analyzer (CDA) performed a ring plane crossing measurement. This was followed by a VIMS OmiCet stellar-Saturn occultation and a remote sensing observation of the Enceladus plumes.

Tuesday, May 10 (DOY 130)

A mission planning forum was held today to review propellant use in S66 and S67 and status of the propellant budgets. A consumables status is provided on a regular basis so the Project can maintain cognizance of propellant usage and end of mission margins.