[quote=Raineh Daze]
This is not either of those you mentioned, but would a techpriest be acceptable? It's not like there wouldn't have been at least one on the ship.
[/quote]

Techpreists can sometimes be in an Inquisitor's entourage, actually, so that could work, at the GM's discretion, of course. Really depends on if we're being an Inquisitor's group, or vanilla Imperial Guard.

[quote=VKAllen]
Oh damn. Not the Adeptus Astartes. I am really interested in joining, but I only know mostly Astartes stuff.
[/quote]

I'm linking you to [url=http://warhammer40k.wikia.com/wiki/Warhammer_40k_Wiki] one of the most comprehensive sites for Warhammer lore I've ever found.[/url] It's helped me a ton when I've needed to brush up on something.