I'm really surprised on a forum like HN that there isn't more questioning of what the Joint Simulation Environment is really supposed to do and why the development of a simulation should hold up the full production of a tactical aircraft.

JSE is really interesting, it's meant to be a high-fidelity electronic warfare simulation with actual aircraft software in the simulation loop. The F-35 that's present in the JSE is the same code that is running on a real jet, with sensor models specifically developed by all the sensor vendors. All this is fed with the latest intelligence data on threat aircraft and emitters. The point of all this is, the US should be able to better develop the aircraft -- and other aircraft types -- in the future if it has a high tech digital testing ground that it can step through iterations with very quickly.

As far as I can tell nothing like this has been done before so it's no wonder that it's taking a while.

Here's a US Navy PDF briefing on the JSE: https://ndiastorage.blob.core.usgovcloudapi.net/ndia/2018/te...