Instead, Starfleet decided to scale up an existing design and mate it with Galaxy components. As it happened, the hull chosen for this was that of the refit Constitution class. The primary factor was size - the Constitution hull was exactly one half of the size necessary for the Galaxy saucer, allowing it to be scaled up by simply replacing every single deck with two. Once approved, work proceeded swiftly - although the project still suffered delays when faults emerged with the remaining Galaxy elements. Nevertheless, the first Rigel class vessel was commissioned in 2358. A four year production run put nine of these vessels into the fleet.

The Rigel is one of the relatively few Starfleet designs with three nacelles. The ship has three basic modes; all three nacelles can operate together, the upper pair can operate independently, or the lower nacelle can operate alone. By alternating between the upper pair and lower nacelle the Rigel can rest nacelles periodically whilst maintaining warp speed, so increasing the average cruise speed which can be maintained or - more importantly for deep space exploration - extending the life of the warp coils.

The Rigels have generally served on long range, long duration exploration missions where they have performed well up to expectations. They are therefore a relatively rare sight within the core worlds of the Federation, although a few have served there. Most notably the USS Tolstoy was part of the fleet which engaged the Borg at Wolf 357, where it was lost with all hands. The Rigel-class USS Akagi also served as part of the blockade fleet which prevented Romulan supplies from reaching the Duras family during the Klingon civil war.