About Star Wolves 2 & 3

[Alvalio]

Hi. I'm playing the first one of the series, but I have a question: are the sequels 2 & 3 expansions or independent games? I'm playing it on hard, and I'm loving my characters(they're fine pilots), so, I lose all their learned skills in those sequels(and all the mothership's cargo - fighters, weapons, systems etc -) or can I export/import them somehow(it would make more sense, since you can play with Hero, Ace among others again)?

Thank you very much

I'm loving the game.

Regards.