Magnificent Seven in space.
In a review of MS, "Mathewscott8" wrote that the Magnificient Seven "could be transposed to just about any genre (have we seen it in space yet?"
The answer is "yes." The film is called Battle Beyond the Stars (1980). The plot outline is "Seven futuristic mercenaries are assembled to defend a helpless farm colony from an evil overlord." Former MS actor Robert Vaughn is in it.