The USM (United Systems Military) Auriga is a fictional spaceship depicted in the fourth installment of the Alien quadrilogy, Alien: Resurrection and is by far the largest vessel depicted in the Alien series. A large, well-equipped military vessel, the Auriga is primarily used for illegal medical research and biological weapons development. It has a small crew of medical scientists and security personnel, and is commanded by the corrupt USM General, Ramón Perez.