Sorry to be a bit late on this but the javelin seems more like a TL7 missile.

At TL6, I’m thinking of an SA-2 Guideline/S-75 Dvina or a Bloodhound.

https://en.m.wikipedia.org/wiki/S-75_Dvina
https://en.m.wikipedia.org/wiki/Bloodhound_(missile)

I choose those two because of the Airfix plastic models that I built.

These are big anti-aircraft missiles but the SA-2 is mobile and the Mk4 Bloodhound would have been.

Both have a 200kg warhead (proximity fuse) which could worry the PCs, although not as much as the 6kt nuke option!

They also have a much better speed, range and altitude.

Hi-tech military should have no problem shooting them down with point defence lasers or just confusing their guidance systems but if the player’s ship is targeted they’ll only have perhaps 10-20 seconds to decide what to do if there isn’t an automatic defence program running.

Phil Kitching