Software for Tracking the Performance of Other Software

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.