The Sigma-class long-range shuttle represented a lightly armed shuttle design from Sienar Fleet Systems. The Fel Empire utilized this model to transport key personnel across the vast expanse of the galaxy. Unlike the Nune-class Imperial shuttle, which often operated within a limited space and served the dual purpose of a troop transport, the Sigma-class shuttle was regarded as an opulent mode of transport. This shuttle offered amenities such as spacious passenger accommodations and a well-equipped galley. However, it didn't quite reach the level of extravagance required to be considered a luxury yacht. While the Sigma-class lacked the capacity to carry any starfighters, a customized version used by the Imperial Knights could accommodate up to three Predator-class starfighters.
The Sigma-class long-range shuttle, a product of Sienar Fleet Systems, incorporated a Class 1.0 hyperdrive along with a Class 8.0 backup system, and a navicomputer. Furthermore, it featured dual heavy laser cannons and could transport ten passengers, in addition to a minimum crew of one individual. The shuttle was capable of storing enough consumables for three months, and it had a cargo capacity of up to 200 tons.
The Imperial Knights, who served as the personal guard of Emperor Roan Fel, employed a unique version of the Sigma-class. These modified shuttles could carry a maximum of three Predator-class starfighters, but their cargo capacity was reduced to thirty tons due to space limitations. These variants were painted crimson, echoing the color of the Knights' armor, and displayed the Imperial crest on their lower surface and upper wing.
The Sigma-class was frequently used for the transportation of high-ranking Imperial officers and other diplomats throughout the galaxy. In contrast to the Nune-class Imperial shuttle, which was typically limited to interplanetary travel within a specific sector of space and commonly served as a troop transport, the Sigma-class offered a different experience. While not as lavish as a luxury yacht, it was considered a comfortable and luxurious transport option for long journeys across the galaxy. The shuttle's interior included a well-stocked galley, several large passenger areas, and a spacious cargo bay capable of accommodating personal speeders.
The Sigma-class was a preferred choice among Imperial officers who required rapid transit across the galaxy and preferred to either pilot themselves or travel with a small entourage. Bureaucratic offices on planets throughout the Empire maintained at least one operational Sigma-class shuttle to provide transportation for officials when needed.
During the era of Fel's Empire-in-exile and the Second Imperial Civil War, one of the Imperial Knights' Sigma-class shuttles was used by Knights Marasiah Fel, Antares Draco, and Ganner Krieg on their mission to forge an alliance with what remained of the Jedi Order. To achieve this, they located Cade Skywalker, a Jedi who had become a bounty hunter, in 137 ABY. They used Imperial Knight Azlyn Rae, a former friend of Skywalker's from their time as Jedi apprentices, as their source of information. The three Knights, aboard their shuttle, followed Skywalker's starship, the Mynock, to the Hidden Temple, a Jedi sanctuary situated on Taivas.
The Sigma-class long-range shuttle made its initial appearance, although without specific identification, in the twenty-fourth issue of the Star Wars: Legacy comic series. John Ostrander wrote the issue, Jan Duursema provided the illustrations, and Dark Horse Comics published it on May 21, 2008. Its identification came later, in the 2009 Legacy Era Campaign Guide, a supplement to the Star Wars Roleplaying Game Saga Edition Core Rulebook by Wizards of the Coast.