The Flight Software Memory Tracker (FMT) computer program is a collection of utility subprograms developed for use on the ground to track images of the flight software (FSW) in the computers aboard the Cassini spacecraft. [As used here, "images" signifies both (1) the memory load and updatable parameters in the spacecraft computers and (2) logically equivalent representations thereof.] FMT maintains a history of every FSW image aboard the spacecraft ("FSW image" for short), updating the ground copies of the images ("FMT images" for short) whenever the FSW images are updated. When FSW images are updated by uplink commands transmitted to the spacecraft, FMT can translate the commands into update data groups to be appended to FMT images. FMT images can also be updated by readout from spacecraft computer-memory addresses, which readout is performed in addition to normal telemetry downlink. FMT can also generate commands to update both FSW and FMT images at a specified time. The FMT images can be evaluated at any historic time, can be queried for history and statistics, and can be processed to obtain, for example, human-readable values of parameters in engineering units. FMT, which is written in Java, can be ported to computers, with various architectures and operating systems, that are equipped with Java interpreters.

This program was written by Edwin Kan, Allan Wax, and Hal Uffelman of Caltech for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at under the Computer Software category, or circle no. 147on the TSP Order Card in this issue to receive a copy by mail ($5 charge).


This Brief includes a Technical Support Package (TSP).
Software for tracking the performance of other software

(reference NPO20200) is currently available for download from the TSP library.

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