From: French Space Agency
Posted: Sunday, February 6, 2011
The most recent spacecraft telemetry was acquired on Feb. 1 from the Deep Space Network tracking complex at Madrid, Spain. 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, Jan. 26 (DOY 026)
For years researchers have been debating whether Enceladus, a tiny moon orbiting just outside Saturn's rings, is home to a vast underground ocean. Is it wet--or not? Now, new evidence is tipping the scales in favor of yes. Not only does Enceladus likely have an ocean, that ocean is probably fizzy like a soft drink and could be friendly to microbial life. For the full story, go to the following NASA Science News report: http://science.nasa.gov/science-news/science-at-nasa/2011/26jan_fizzyocean/.
Friday, Jan. 28 (DOY 028)
In this week's science observations, the Cosmic Dust Analyzer (CDA) performed a 13-hour interstellar dust observation. The Composite Infrared Spectrometer (CIRS) performed an 11-hour observation to measure oxygen compounds in Saturn's stratosphere. The Ultraviolet Imaging Spectrograph (UVIS), along with the Visual and Infrared Mapping Spectrometer (VIMS) and ISS, performed an 11-hour observation of Saturn's auroral region to investigate variability in auroral emissions. The Radar team obtained a distant Titan radiometer observation while simultaneously collecting data for calibration. A distant UVIS-led observation of Dione was performed on approach to Saturn periapsis, which was focused on icy satellite observations, . This was followed by two sets of Enceladus plume observations led by ISS, along with a CIRS thermal mapping of Mimas. Observations of Enceladus' surface were obtained by all of the Optical Remote Sensing instruments, followed by a Mimas-Helene-Mimas observation block to probe the geology and surface compositions of these moons. The week closed with observations searching for small satellites in the Mimas L4 and L5 Lagrange points, the regions 60 degrees ahead of and behind Mimas, respectively, in its orbit around Saturn. These regions are potentially stable locations for objects; small moons orbit Saturn in the L4 and L5 points of Tethys' and Dione's orbits.
Saturday, Jan. 29 (DOY 029)
The Radio Science Subsystem (RSS) performed a Ka-band Operational Readiness Test (ORT) today over Goldstone's DSS-25 station in preparation for the upcoming Titan 74 (T-74) encounter.
Sunday, Jan. 30 (DOY 030)
The Live Inertial Vector Propagator (IVP) Update and Live Moveable Block (LMB) for DOY 030 to 031 begins execution today. The LMB provides for the update of the vectors and the timing as necessary.
Monday, Jan. 31 (DOY 031)
Orbit Trim Maneuver (OTM) #276 was performed today. This maneuver is setting up the spacecraft's trajectory for the T-74 encounter on Feb. 18. The Reaction Control Subsystem (RCS) burn began at 05:59 AM PST. Telemetry immediately after the maneuver showed a burn duration of 13.125 seconds, giving a delta-V of 0.021 m/s. All subsystems reported nominal performance after the maneuver. Non-targeted flybys of Epimetheus, Calypso, Prometheus, Enceladus, and Helene occurred today.
Tuesday, Feb. 01 (DOY 032)
A feature story called "Cassini Sends Back Postcards of Saturn Moons" is available on the Cassini web site. It describes how on Jan. 31, Cassini passed by several of Saturn's intriguing moons, snapping images along the way. Cassini passed within about 60,000 kilometers of Enceladus and 28,000 kilometers of Helene. It also caught a glimpse of Mimas in front of Saturn's rings. In one of the images, Cassini is looking at the famous jets erupting from the south polar terrain of Enceladus. For images and more information on this subject, link to: http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20110201/.
A Mission Planning (MP) forum was held today and the topic was integration and implementation of Low Gain Antenna gravity field observations during Titan flybys. The purpose of the meeting was for the Project to review the proposed processes for integrating, implementing, and approving these observations for candidate flybys as well as discuss the risks associated with switching to the low gain antenna during Titan flybys. The project identified several open issues that need to be resolved before the first low gain antenna gravity field observation is implemented.
Commands were uplinked to the spacecraft today in support of S66 for the ISS Memory Readout (MRO) planned for execution on DOY 035. This is to read an error table in response to a WAC machine error seen on DOY 023.
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