28 Sep 2001
(Source: Jet Propulsion Laboratory)
Cassini Weekly Significant Events for 09/20/01 - 09/26/01
The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, September 26. The Cassini spacecraft is in an excellent state of health and is operating normally. Information on the spacecraft's position and speed can be viewed on the "Present Position" web page, http://www.jpl.nasa.gov/cassini/english/where/.
Recent instrument activities include an Interplanetary Hydrogen Survey by the Ultraviolet Imaging Spectrograph, two Radio and Plasma Wave Science High Frequency Receiver calibrations, a Visual and Infrared Mapping Spectrometer timing test, and a Radio Science Subsystem (RSS) dataflow test. Engineering activities taking place onboard the spacecraft this week include an Attitude Control Subsystem (ACS) deadband test, which will provide data for a trade study on hydrazine consumption under two Reaction Control Subsystem deadband settings. A real-time command was uplinked to the spacecraft to clear the ACS high-water marks.
The eighth Huygens in-flight check-out (F8) was successfully executed this week. Onboard the spacecraft, the Probe Support Avionics were turned on and operated for several hours. The telemetry data was downlinked in real time from Cassini to the Goldstone tracking station and broadcast to the Huygens Probe Operations Center in Darmstadt, Germany, via the JPL/Cassini ground system. An initial assessment of the telemetry indicates that all sub-systems and payloads performed as expected, and the science data have already been distributed to all Huygens science teams, with preliminary reports from each team expected within the next week. The F8 Operations Report will be ready for the F8 Check-out Review, which will take place at European Space Research & Technology Centre (ESTEC) on December 5 & 6.
The RSS team conducted the first of two data flow tests this week. The objective was to further RSS Verification and Validation efforts in preparation for the Gravitational Wave Experiment (GWE). The RSS team also uplinked a Ka-band signal to the Ka-band Translator (KaT) to continue development of a final KaT operational strategy for the GWE.
The Sub-Sequence Generation (SSG) phase of the C29 sequence process has been completed and the Preliminary Sequence Integration & Validation (PSIV) phase has begun.
The Command and Data Subsystem (CDS) Flight Software (FSW) team delivered the fourth iteration of the CDS FSW v9.0 as part of the continuing development of that FSW package.
System Engineering (SE) worked with the Uplink Operations team to schedule the Mission Sequence Subsystem (MSS) D8.0 delivery. This delivery must accommodate the new command database (ACS and CDS FSW changes) and the change to the new Sun Operating System, in addition to supporting the normal cruise sequences. The plan was presented to Program Management for review.
Mission Assurance has updated the Program Review Plan & Schedule. This plan outlines the Programmatic Reviews that are scheduled to take place for the remainder of the mission, particularly those addressing readiness for Saturn Orbit Insertion and Probe Relay operations.
A paper entitled Managing Risk for Cassini During Mission Operations and Data Analysis has been written by Mission Assurance and submitted for the 2002 IEEE Aerospace Conference. This paper describes the Risk Management Process that Cassini has put in place to manage operational risks, and includes preliminary metrics and outlines what metrics will be kept to ensure that the process is effectively managing risks. The paper is scheduled to be presented at the conference in March 2002.
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