The James Webb Space Telescope (JWST) Integrated Simulation and Test (JIST) environment is a software-only system simulator that provides an environment to exercise JWST flight software subsystems and interfaces. JIST is capable of executing the unmodified flight software binaries in an operational environment that can be configured on a single personal computer. JIST utilizes the JWST ground system, ground system command and telemetry databases, simulated flight computers, instrument simulators, and environment simulators. Some of the capabilities provided by JIST include the ability to load and run any version of the flight software, inject errors (faults) from ground system test procedures, save simulation state (processor and simulators), and simulate external hardware devices. Many components are potentially reusable on future missions. In addition, the modeling techniques and models have potential commercial applications for projects that deploy similar hardware solutions.
The IV&V Program does not have a means to exercise the JWST flight software subsystems in a repeatable and consistent fashion, and the IV&V Program does not have sufficient budget to set up a hardware-in-the-loop test environment. JIST provides a mechanism to set up a test environment for the IV&V Program to dynamically validate flight software behaviors and examine unexpected flight software behaviors (independent tests). JIST also has the potential to provide a means to validate new test procedures prior to executing on hardware-in-the-loop environments, decrease procedure development time, and provide a ground operations training platform.
JIST provides a cost-effective means for the IV&V Program to perform dynamic analysis on software systems; provides a test framework for mission operations teams; provides a cutting-edge test environment with accompanying tools; and makes testing embedded flight software test environments more accessible and convenient for users and testers.
JIST can be configured to execute on a single personal computer, and can test hardware faults in nominal and off-nominal conditions. It can save and reload test scenarios at any point during a test, integrate easily with commercial debuggers, utilize unmodified flight binaries, and not require hardware acquisition or maintenance.
This work was done by Brandon Bailey, Justin Morris and Mark Pitts of Goddard Space Flight Center; Daniel Nawrocki of Athena Sciences; Steven Seeger of MPL; Justin McCarty and Scott Zemerick of Galaxy Global Corporation; Jeffery Joltes and Tim Riley of Allegheny Science & Technology Corporation; and Charles Rogers of Embedded Flight Systems, Inc. GSC-16739-1