In 2277, a class of up to five space control ships was planned by Starfleet. One became the prototype transwarp vessel USS Excelsior and was reclassified as a heavy cruiser, another became the one space control ship actually built, USS Ingram. (USS Excelsior Ingram Class Plans) Historical accounts differ as to what happened to the remaining spaceframes at Spacedock.
- The George Washington-class space control ships may exist in an alternate timeline from one where the Ingram-class ships exist.
In the late 24th century, interest in the space control ship concept resurged. In one timeline branch, some Galaxy-class explorers were refit to this type, as part of the Space Control Ship Project. (Star Trek: New Order) In a different timeline, the Griffon-class space control ships came to be, with one of the vessels refit from the 80-year-old Ingram-class USS Pendragon. (Dockyard Review 4:3 (July 2370): "The Griffon Class SCS-X: Starfleet's Experimental Extended-Range Exploration Vessels")