Risk Reduction Scenarios

One type of Independent Testing, provided by the JSTAR team and performed by the NASA IV&V Program, is Risk Reduction Scenarios. These are scenarios (or actions that the spacecraft must perform) that have been identified as needing additional testing due to their mission critical status. Risk reduction tests are performed by utilizing the JSTAR simulators to run the tests and verify the flight software behaviors.

A test bed for Risk Reduction Scenarios for the James Webb Space Telescope is its JSTAR developed simulation software, the JWST Integrated Simulation and Test (JIST) environment. Examples of risk reduction scenarios that have been running for this project include software response to a stuck thruster, the failing of a primary computer and the system’s switch to a backup computer, communication timing between different computers controlling the spacecraft telescope and the observational data it collects, and launch and ascent software actions. These items require additional testing because if the software fails then the mission could be considered a loss.

JSTAR facilitates the ability of NASA IV&V to perform Risk Reduction Scenarios by its development of simulation environments, such as JIST’s role for the James Webb Space Telescope.