The USCSS Nostromo was a Weyland-Yutani Lockmart CM 88B Bison M-Class starfreighter used as a commercial hauler between Thedus and Earth. The Nostromo carried (or rather pulled) a massive refinery behind it for processing over 20 million raw tons of ore on the long trip to Earth. This refinery is never actually inhabited, as even the Xenomorph remained on the Nostromo itself. In effect, the Nostromo was more of a tug or a tractor truck rather than a freighter.

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