PRE-TOS Comet Class 1

second-generation of M/AM-powered ships. At the ends of their research careers in 2165, UES FIREBALL and UES ROCKET joined Starfleet and served as couriers and diplomatic transports until 2193
UES FIREBALL and her sister ship, UES ROCKET (XL-6), continued to be used for extensive testing of propulsion theories and new technologies, which helped greatly in the development of the