> The JWST science operations will be driven by ASCII (instead of binary command blocks) on-board scripts, written in a customized version of JavaScript. The sc

> The JWST science operations will be driven by ASCII (instead of binary command blocks) on-board scripts, written in a customized version of JavaScript. The script interpreter is run by the flight software, which is written in C++. > The flight software operates the spacecraft and the science instruments. The on-board scripts will autonomously construct and issue commands, as well as telemetry requests, in real-time to the flight software, to direct the Observatory Subsystems (e.g., Science Instruments, Attitude Control, etc.). The flight software will execute the command sent by the calling on-board script and return telemetry, which will be evaluated in real-time by that on-board script. The calling script will then send status information to a higher-level on-board script, which contains the logic to skip forward in the observing plan in response to certain events (see Section 4.1).