Royal Air Force. "Full operating capability" for the UK's carrier strike capability had been planned for 2023 (2 squadrons or 24 jets operating from one carrier). The longer-term aim remains for the ability to conduct a wide range of air operations and support amphibious operations worldwide from both carriers by 2026. They form the central part of the UK Carrier Strike Group. Future The Queen Elizabeth-class ships are expected to have service lives of 50 years. United States Current 11 CATOBAR carriers, all nuclear-powered: : ten 101,000-tonne, fleet carriers, the first of which was commissioned in 1975. A Nimitz-class carrier is powered by two nuclear reactors providing steam to four steam turbines. , one 100,000-tonne, fleet carrier. The lead of the class came into service in 2017, with another nine planned to replace the aging Nimitz-class ships. Nine amphibious assault ships carrying vehicles, Marine fighters, attack and transport helicopters, and landing craft with STOVL fighters for CAS and CAP: : a class of 45,000-tonne amphibious assault ships, although the first two ships in this class, (Flight 0) do not have a well decks, all subsequent ships (Flight I) will have well decks. Two ships are currently in service out of a planned 11 ships. Ships of this class can have a secondary mission as a light aircraft carrier with 20 AV-8B Harrier II, and in the future the F-35B Lightning II aircraft after unloading their Marine expeditionary unit. : a class of 41,000-tonne amphibious assault ships, members of this class have been used in wartime in their secondary mission as light carriers with 20 to 25 AV-8Bs after unloading their Marine expeditionary unit. Seven ship currently in service of an original eight, with one lost to fire. Future The current US fleet of Nimitz-class carriers will be followed into service (and in some cases replaced) by the . It is expected that the ships will be more automated in an effort to reduce the amount of funding required to maintain and operate the vessels. The main new features are implementation of Electromagnetic Aircraft Launch System (EMALS) (which replaces the old steam catapults) and unmanned aerial vehicles. In terms of future carrier developments, Congress has discussed the possibility of accelerating the phasing-out of one or more Nimitz-class carriers, postponing or canceling the procurement of CVN-81 and CVN-82, or modifying the purchase contract. Following the deactivation of in December 2012, the US