Unprepared is a nice way to say it. I'd call it heavily damaged. And no matter how radiation resistant your hull is, it won't do any good if said hull is full of holes from a recent battle and crashjump.
Also I somehow doubt a fighter could survive very long in the 2 million degree kelvin of the sun's corona.
Well, Sara's idea has quite something to it. If it is indeed unthinkable for a fighter, why not do it as another bonus-capship mission? Or make it a specially shielded (proabably stealth) fighter, add an SEXP - as soon as your shields drop... you're mincemeat.
THAT would be a challenge even for experienced players, to keep that up if it came to a dogfight (depending on the other mission design). Combine it with failing jump drives, reactor problems that indicate your shield probably won't hold out much longer, enemies closing in and nearly discovering you - and you can create quite a sense of urgency for one mission.
You could even create urgency without enemies. Add a bunch of SEXPs, in which you have to repair something via 1,2,3,4 etc. in the right order. Always failing? The answer will be in the specifications in your tech room. Maybe a bit cruel, but it will make you either read it or go through heaps and heaps of trial and error.
