James Webb Space Telescope Will Run JavaScript [pdf]
stsci.edu
stsci.edu
> 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. [...]
Section 3.5:
> JWST uses an extended version of JavaScript, which was developed as a COTS product called Nombas ScriptEase 5.00e. ScriptEase provides functionality common to many modern software languages and follows the ECMAScript standard. [...]
Also see the diagram in Section 3.3.