Cassini Significant Events 03/18/09 – 03/24/09

The most recent spacecraft telemetry was acquired on Mar. 24 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/operations/present-position.cfm.

Wednesday, March 18 (DOY 077):

The S48 background sequence was reactivated late last night at 2009-076T20:04:48 PDT. The only remaining activities to complete the thruster swap to the B branch are the execution of two spacecraft engineering activities originally scheduled for the time when the background sequence was deactivated.

Because the first Live Update Block (LUB) in S49 occurs within 24 hours of the start of sequence execution, the kickoff meeting was held today during S48. Teams will have the weekend to analyze the data and the Go/No Go meeting will be held on Monday.

An encounter strategy meeting was held today to cover the period between Mar. 27 and Apr. 4, Titan flybys T51 and T52, and OTM 186.

Thursday, March 19 (DOY 078):

Files for the final input port in the Science Operations Plan process for S51 were due today.

Friday, March 20 (DOY 079):

The final sequence approval meeting for S49 was held today. The background sequence will go up to the spacecraft Sunday night, and the sequence will begin execution on Thursday, Mar. 26.

A non-targeted flyby of Titan occurred today.

Cassini Outreach presented a Cassini Mission Roundup and International Year of Astronomy talk at the Thousand Oaks, CA, Discovery Center’s Super Science Sunday on Mar. 22. Over 1000 science enthusiasts of all ages visited hands-on science activities, heard several speakers, viewed Cassini images, received Cassini outreach materials, and viewed the planet Saturn as they were leaving.

On Saturday, Imaging Science continued Titan cloud monitoring observations begun the day before, the Cosmic Dust Analyzer was prime for a ring plane crossing, the plumes of Enceladus were observed in order to study their phase function, and the Composite Infrared Spectrometer (CIRS) performed a ring vertical temperature scan, this time from the opposite side of the ring plane than has been observed previously.

On Sunday another Titan monitoring observation executed which provided isolated snapshots. This type of observation is intended to improve understanding of how often there are clouds on Titan, where they are appearing as the seasons change, how fast and in what direction the winds blow, and also how the haze evolves with the seasons. Another CIRS vertical temperature scan of the rings at a different location and a Visual and Infrared Mapping Spectrometer ring stellar occultation followed this.

Monday, March 23 (DOY 082):

Because of the deactivation of the background sequence to support the thruster branch swap, the Spacecraft Periodic Engineering Maintenance activity scheduled for that time frame was canceled. The activity was converted to a series of real time commands and uplinked to the spacecraft last week for execution today.

Tuesday, March 24 (DOY 083):

Due to the excellent accuracy of Orbit Trim Maneuver (OTM) 183x last week, the first on the B-Branch thrusters, there is only a small shift in the predicted flyby point for the Titan 51 encounter relative to the planned target. In addition there are virtually no differences with respect to Optical Remote Sensing Instrument pointing for the remaining activities in S48 if OTM-184 is performed or canceled. As a result, OTM-184 has been cancelled.

Today the Spacecraft Office held an Engineering Activities Review for S54.

New flyover maps of Titan show the 3-D topography and height of the 1,200-meter mountain tops, the north polar lake country, the vast dunes more than 100 meters high that crisscross the moon, and the thick flows that may have oozed from possible ice volcanoes. The topographic maps were made from stereo pairs of radar images. For the full release and two animated flyovers, link to: http://saturn.jpl.nasa.gov/news/newsreleases/newsrelease20090324/