Yeah, you can edit the class name easily (as Mr. Long Name indicated), but actually changing the ship's name is not possible in FRED. I think there is a script that sort of allows you to do that, but all it does it remove the old ship and makes a new one copying all attributes. Which mission/part in Vassago are you talking about? (Btw you can use [ spoiler][/ spoiler] tags for spoilers (without that space))
Thanks for the tip!
I'm talking about that one mission where you play as a Shivan. It's like a dream, I think? Intermezzo?
Wait, will filling in the "alt name" field in the Ship Edit window replace the ship class name? And what does the "callsign" field do?