From: Jet Propulsion Laboratory
Posted: Friday, January 13, 2012
The most recent spacecraft telemetry was acquired on Jan. 9 from the Deep Space Network tracking complex at Goldstone, California. The Cassini spacecraft is in an excellent state of health and with the exception of the CAPS instrument being powered off, 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. 4 (DOY 004)
A news release called "New Computer Model Explains Lakes and Storms on Titan" is available on the Caltech Media Relations web site. Saturn's largest moon, Titan, is an intriguing, alien world that's covered in a thick atmosphere with abundant methane. With an average surface temperature of a brisk -300 degrees Fahrenheit and a diameter just less than half of Earth's, Titan boasts methane clouds and fog, as well as rainstorms and plentiful lakes of liquid methane. It's the only place in the solar system, other than Earth, that has large bodies of liquid on its surface. Using a combination of ground-based and Cassini data, researchers at Caltech have developed a computer model of Titan's atmosphere and methane cycle that explains many of these phenomena in a relatively simple and coherent way. For more information on this subject link to: http://media.caltech.edu/press_releases/13484.
Thursday, Jan. 5 (DOY 005)
Science activities this week focused on a number of observations by the Imaging Science Subsystem (ISS) and other Optical Remote Sensing (ORS) instruments. On approach to periapsis, ISS took a look at Enceladus' plumes and the Composite Infrared Spectrometer (CIRS) performed a Saturn Limb Map observation to obtain stratospheric thermal structure by means of limb sounding in the mid-infrared. ISS and VIMS performed two Saturn emission angle scans by observing different emission angles in different latitude bands; these data will help to understand the photometric characteristics of Saturn at different wavelengths. ISS took a look at Titan as part of the Titan monitoring campaign, while CIRS recorded a Saturn mid-IR map to determine upper troposphere and tropopause temperatures. Concluding the week, the ORS teams made further observations of Titan, and a set of complementary observations by ISS and CIRS measured Saturn winds and composition. Meanwhile, back on Earth, members of the UVIS team met for a team meeting at Caltech, Jan 5-7, to discuss science results and plans for future observations.
Friday, Jan. 6 (DOY 006)
The Cassini Navigation team accepted formal delivery of Monte, the replacement tool for its legacy navigation software, and began using it in operations today. The purpose of the Monte software is to provide all navigation-related functions in a single, integrated system.
Saturday, Jan. 7 (DOY 007)
Members of the Science Planning and Sequence Team (SPST) supported multiple meetings with DSN schedulers and Section 317 representatives to discuss issues related to late DSN station allocation deliveries and scheduling software issues.
The Cassini Mission Assurance Manager started reviewing the Project Risk database and scheduled a meeting with the Instrument Operations Team lead to go over instrument-related risks; these risk descriptions were last updated in 2009. The MAM will work with each team lead to update the rationale and risk rating, and for next few weeks will start scheduling meetings with each team lead, while continuing to support sequence development activities as needed.
Sunday, Jan. 8 (DOY 008)
The Navigation Team is in the process of determining if the next scheduled maneuver, Orbit Trim Maneuver (OTM) #306, is needed; it's scheduled to execute on Jan. 16. OTM-306 is the sole maneuver between Titan flyby T-80 and T-81, a situation made possible by the fact that both of these are high altitude flybys.
Monday, Jan. 9 (DOY 009)
The Ultra Stable Oscillator (USO) was powered off today for 30 minutes. This was a diagnostic step in the investigation of the USO anomaly that occurred on Dec. 23. The telemetry received while turning the USO equipment off and back on was as expected. Further analysis of this anomaly is still ongoing.
Both ISS and VIMS lost some data and encountered degraded products due to the USO anomaly that started on DOY 357. The carrier tracking loop bandwidth has been changed to 10 Hz over the one-way portion of each tracking pass for which the auxiliary oscillator is now used, and as result, data quality has improved to where it was previously on the USO.
Tuesday, Jan. 10 (DOY 010)
A feature story called "Cassini Top 10 Science Highlights -- 2011" is available on the Cassini web site. All throughout 2011, the Cassini spacecraft collected science data at a rapid pace. Mission scientists provided exciting results all year long, from scrutinizing a huge new storm on Saturn, to discovering salty particles in Enceladus' plumes, to studying Saturn's rings with radio science experiments. For images and a look at last year's best science, link to: http://saturn.jpl.nasa.gov/news/cassinifeatures/feature20120110/
The Instrument Operations (IO) /Multi-Mission Image Processing Laboratory (MIPL) had a planned downtime today to switch two operations servers to backup hardware. This was done to allow firmware and patch updates to the T2 Logical Domains (LDOMs) hosting the operations and data storage (ZFS) servers.
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