The Prometheus and Daedalus are both fictitious interstellar starships in the Stargate TV series

The Prometheus was the first starship that Earth built. The project was code named Prometheus, but that later became the name of the ship. It was built from a mix of alien and human technology at Area 51 (ring rooms throughout the ship, Asgard shields and hyperdrive, human railguns and missiles). While it was being completed, a rogue group of NID made off with the ship (Prometheus, Part 1 and 2). The Asgard took it back, and utilized it and SG-1 to defeat the Replicators. Prometheus led a force of F-302 fighters to combat Anubis's fleet in the battle above Antartica (Lost City, Part 2). Lastly, Prometheus was sent on a mission to contact Atlantis Base in the Pegasus Galaxy, but was forced to turn back (Prometheus Unbound). It is uncertain whenter we will see Prometheus in the seasons to come, simply because it has been rendered somewhat obsolete by the second generation battlecruiser the Daedalus.

The Daedalus is the sister ship to the Prometheus. It has better systems, although the actual systems retain their place of origin i.e: the shields and hyperdrive are still Asgard, etc. It is on it's way to save Atlantis in the Pegasus Galaxy.