A Starfleet science class of the 2250s whose two ships, Discovery and Glenn, were built to test the experimental displacement-activated spore drive.
The Crossfield-class is a Starfleet science vessel class of the 2250s. Its ships have a large saucer, an angular secondary hull and a rotating section linked to their most unusual feature, the displacement-activated spore drive. This drive uses the mycelial network to jump across vast distances almost instantly.
Only two ships of the class are known: the USS Discovery and the USS Glenn. The Glenn's crew died in a spore drive experiment gone wrong, leaving Discovery as the sole working example. Under Captain Gabriel Lorca, Lieutenant Paul Stamets developed the drive further, and it became one of Starfleet's strongest weapons during the Klingon War. Discovery later travelled to the 32nd century, where it was refitted with the latest technology.
The Crossfield-class is central to Star Trek: Discovery and its exploration of the spore drive. Its powerful but risky technology led Starfleet to classify the drive and its ships, and its story drives much of the show's plot across centuries.