11 May 2001
(Source: Jet Propulsion Laboratory)
Cassini Weekly Significant Events for 05/03/01 - 05/09/01
The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Monday May 7. The Cassini spacecraft is in an excellent state of health and is operating normally. (Subsequent to the time period covered by this report, the Cassini spacecraft entered safing. The cause is well understood, the spacecraft is in a completely safe state, and recovery efforts are underway. Details will be included in next week's report.) Information on the spacecraft's position and speed can be viewed on the "Present Position" web page at ("http://www.jpl.nasa.gov/cassini/english/where/").
Recent spacecraft activities include characterization and power-off of Solid State Recorder (SSR)-A. The characterization tests included a memory test, data formatter test and module controller interface tests. Also performed was a procedure to patch the Command & Data Subsystem (CDS) Flight Software (FSW) in the SSR-B non-default partition with an update for the Magnetometer Subsystem (MAG) replacement heater Solid State Power Switch (SSPS) algorithm. The procedure included reloading CDS-B with the newly patched FSW, and patching CDS-A FSW running in RAM with updates for the MAG heater and the Low Gain Antenna (LGA). All activities executed nominally.
Additional spacecraft activities included the a Radio and Plasma Wave Science (RPWS) High Frequency Receiver (HFR) calibration, a high water mark clear, and uplink of an Instrument Expanded Block (IEB) and execution of a sensor mode checkout minisequence for Cassini Plasma Spectrometer (CAPS).
The Radio Science (RSS) team concluded the Gravitational Wave Experiment (GWE) system test #1 this week. About 40 hours of Ka-2 coherent data, 60 hours of Ka-1 coherent data, and over 100 hours of X-band data were collected. Additionally, the team collected about 60 hours of media calibration data that will be processed into path delay files for each of the DSN tracks. The system test also provided further information for characterization of the Ka-band Translator (KaT). The RSS team, with assistance from the DSS-25 Upgrade Task, developed a new Ka-band acquisition template crucial to this effort. The template was used for all DSS-25 tracks.
Science planning tool user scenarios were presented at the Cassini Design Team meeting by the Science Planning team, and ground software tool classifications and related requirements were reviewed at the System Engineering Round Table working group.
The Cassini Mission Plan has been reorganized by the Mission Planning Team in support of a new delivery of the document at the end of May. A review of the maneuver strategy and maneuver timeline of events was held in the Mission Planning forum, and the updated Consumables Report was released.
Mission Assurance has updated the process by which anomalies are reported for Cassini to more accurately reflect current operations. An updated Anomaly Reporting Plan has been distributed for flight team review. The new process will be presented to the Cassini Design Team for approval and implementation. Mission Assurance has also begun tailoring a prototype, web-based Risk Management Tool developed for Cassini, to be consistent with the Program's risk management process. The tool is expected to be released for use within the next month.
The Instrument Operations (IO) Team developed an Event Kernel (EK) web query tool prototype and released it for evaluation by members of the EK working group. This prototype will help the EK development team further refine the requirements for EK data and an interface to that data.
The Cross-Discipline Workshop (CDW) report was published, which summarized the results of the Tour segmentation done by the Tour Splinter Groups formed during the workshop. The Atmospheres Working Group held a teleconference to work on atmospheric occultation requirements.
A group of students operating the Goldstone-Apple Valley Radio Telescope (GAVRT) in coordination with the Cassini RADAR team presented their results to JPL and NASA staff this week. Attending the presentation were RADAR Team Leader and JPL Director Charles Elachi and Cassini Program Manager Bob Mitchell, with Administrator Dan Goldin, U.S. Rep. Jerry Lewis (Redlands, CA) and GAVRT/Cassini Coordinator Scott Bolton attending via telecast from NASA HQ. The GAVRT team observed the long-term and short-term variability of Jupiter's synchrotron emission to provide a solid baseline of Jupiter's radiation belts behavior at the time of the Cassini Jupiter flyby.
Working as science partners with the Cassini RADAR team, the GAVRT team's observations will be used to calibrate the Cassini RADAR instrument. Their observations confirmed the state of Jupiter's radiation belts at the time of the experiment, and provided a unique contribution by observing before and after the flyby.
Cassini presentations were made to the Young Astronauts program on May 2nd and 3rd in Spokane, WA. The Young Astronauts webcasts are broadcast to elementary school children across the U.S. Students phone in with questions at the end of the program.
Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.
Cassini Mission to Saturn and Titan
Jet Propulsion Laboratory
California Institute of Technology
National Aeronautics and Space Administration