SPT 21
SPT 21 was the registry number of a Federation Class C prison shuttle operated by Starfleet in 2256.

That year, SPT 21 transported four prisoners, including Michael Burnham, from a prison to Tellun. En route, the shuttle encountered Species GS54, which drained its power systems. The shuttle's pilot was disconnected from the craft and flew off into space while trying to combat the infestation, but SPT 21 was rescued by the . After three days of repair, the shuttle left the Discovery carrying all of the prisoners except Burnham. ()

Personnel 

Federation shuttles