>>165I'm going to assume by your picture that you meant the Deathwatch.
They primarily fight and study xenos. Space Hulks may be rife with these, but it's the same type of threat 8 times out of ten (genestealers or Chaos) and they don't hunt relics or lost technology as much as proper chapters do, which is one of the main reasons to board a Space Hulk.
Deathwatch is all about finding new ways to combat xenos threats, and the most efficient way to fight xenos in a Space Hulk is already known (Terminators.)