Cassini Significant Events 03/02/11 – 03/08/11

The most recent spacecraft telemetry was acquired on Mar. 7 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, March 2 (DOY 061)

Orbit Trim Maneuver (OTM) #279 was performed today. This was the apoapsis maneuver setting up for the Titan 75 encounter on April 19. The Reaction Control Subsystem (RCS) burn began at 3:30 AM PST. Telemetry immediately after the maneuver showed a burn duration of 89.25 seconds, giving a delta-V of 0.1001 m/s. All subsystems reported nominal performance after the maneuver.

Thursday, March 3 (DOY 062)

The SPST office leads held a meeting today to discuss staffing plans for the DSN schedulers for the rest of FY11 and FY12. Staffing plans are not yet worked for FY12. For the remainder of FY11, there may be a loss of one DSN scheduler but that is still to be determined; support would still be provided by two other schedulers.

Friday, March 4 (DOY 063)

This week the spacecraft was near the apoapsis portion of the orbit, so most of the science observations focused on distance views of the planet and Titan. The Ultraviolet Imaging Spectrograph (UVIS) performed three sets of slow scans across Saturn to form spectral images and probe the upper atmospheric composition. The Magnetospheric and Plasma Science (MAPS) instruments were occupied this week with a magnetospheric boundaries campaign, while the Optical Remote Sensing (ORS) teams made a series of Titan observations as part of the cloud monitoring campaign, which helps in investigating and monitoring weather on Titan. The Composite Infrared Spectrometer (CIRS) made two sets of observations to measure oxygen compounds in Saturn’s stratosphere as a function of latitude. The Magnetometer (MAG) performed a calibration that consisted of a spacecraft roll for determination of sensor offsets. Imaging Science (ISS) and the Visual and Infrared Mapping Spectrometer (VIMS) continued to build their Saturn wind speed template by performing cloud tracking measurements.

Saturday, March 5 (DOY 064)

A Simulation Coordination Meeting was held Feb. 28 for the S68 RADAR Integrated Test Lab testing, which was successfully completed over the weekend.

Monday, March 7 (DOY 066)

The Reaction Wheel Assembly (RWA)-3 was successfully swapped in for RWA-4 today in preparation for S67. Performance on RWA-3 will be closely monitored throughout the S67 sequence. The S67 Reaction Wheel Assembly Bias Optimization Tool (RBOT) design was done using 300 RPM as the lower limit for all three wheels. The previous low RPM limits were 500, 400, and 300 for RWA-1, 2, and 4 respectively.

The S67 sequence began execution today at 2011-066T13:02:00. The sequence will run for 49 days and conclude on April 25. During that time there will be one targeted encounter of Titan and three non-targeted flybys – one each of Telesto, Aegaeon, and Helene. Two OTMs are scheduled, numbered 280 and 281.

A news release called “Cassini Finds Enceladus is a Powerhouse” is available on the Cassini web site. Heat output from the south polar region of Saturn’s moon Enceladus is much greater than was previously thought possible, according to a new analysis of data collected by the Cassini spacecraft. Data from Cassini's composite infrared spectrometer of Enceladus’ south polar terrain indicate that the internal heat-generated power is about 15.8 gigawatts, approximately 2.6 times the power output of all the hot springs in the Yellowstone region, or comparable to 20 coal-fueled power stations. For more information on this subject link to: http://saturn.jpl.nasa.gov/news/newsreleases/newsrelease20110307/.

Tuesday, March 8 (DOY 067)

The S70 Engineering Activities Review took place today. At this review, Spacecraft Office personnel take a look at all spacecraft activities to be performed during the S70 sequence.

An image of Titan overlain on Saturn’s rings was Astronomy Picture of the Day today. Check it out at: http://apod.nasa.gov/apod/ap110308.html