A crew of civilians investigates a distress beacon, but it turn out to be a warning that they were too late to heed.
Alien is another "first to get there" movie which has set the bar for its sub-genre.
It has a dirty old-but-futuristic look to it that really stretches its technological and budgetary limitations. As it turns out, this has given the movie incredible longevity. For a movie as old as this, it easily stands the test of time.