The USM Auriga was the United Systems Military vessel used to conduct cloning experimentation on Lieutenant Ellen Ripley in the late twenty-fourth century. The USM Auriga was 12,000 feet in length and maintained a constant crew of forty-two enlisted Security Officers and seven science officers. An artificial intelligence program, FA-TH-UR, was in charge of managing the ship's autopilot and personnel organisation systems. The Auriga had a mess hall, several reservoirs, sleeping quarters, a surgical lab and several prison pods containing genetically-grown Xenomorphs. Following the escape of several Xenomorph specimens the crew of the USM Auriga abandoned the vessel in its EEVs, although many crew members were killed in the process. The Auriga then autopiloted itself to Earth and exploded high in the atmosphere above Africa.
It is unclear why Ripley 8 and Call decided to crash the Auriga into Earth in such a potentially destructive manner. If they had the ability to reprogram the ship to speed up and crash, they must also have had the ability to change its course. They could have flown it into another planet in the Solar System, or even the Sun, which would have achieved the same aim with far less risk of collateral damage. It is never established what damage is done by the Auriga exploding over Africa, let alone whether the continent is still inhabited (although in the extended Special Edition of the film, Call remarks that she is directing the ship to an uninhabited sector).