What was the name of the spaceship in the original film 'Alien'?

In the 1979 film 'Alien', the USCSS Nostromo is a working class freighter. Here the crew are trying to make a living, tugging a refinery through deep space. The corporation that owns this ship is Weyland-Yutani. It is a corporation that is willing to take advantage of the hard work of its blue collar employees.

It is also Weyland-Yutani that has knowledge of what awaits the Nostromo on the mining planet, LV-426. Weyland-Yutani has the ultimate purpose of bringing the xenomorph XX121 life form back to Earth for experimentation and implementation as a biological weapon.

The film 'Alien' is a science fiction horror story about Lieutenant Ellen Ripley (played by Sigourney Weaver) and her battle with the extraterrestrial species Xenomorph XX121, commonly referred to as "the Alien". When the characters specifically focus upon the ship, the ship's name is used to echo many of the themes and ideas allowing or causing intrigue, action, and development in the movie.