The UGM-133A Trident II, or Trident D5 is a submarine-launched ballistic missile (SLBM), built by Lockheed Martin Space in Sunnyvale, California, and deployed with the United States and Royal Navy. It was first deployed in March 1990, and remains in service. The Trident II Strategic Weapons System is an improved SLBM with greater accuracy, payload, and range than the earlier Trident C-4. It is a key element of the U.S. strategic nuclear triad and strengthens U.S. strategic deterrence. The Trident II is considered to be a durable sea-based system capable of engaging many targets. It has payload flexibility that can accommodate various treaty requirements, such as New START. The Trident II's increased payload allows nuclear deterrence to be accomplished with fewer submarines, and its high accuracy—approaching that of land-based missiles—enables it to be used as a first strike weapon.
A Trident II launch from a submerged Royal Navy submarine.[citation needed]
USS Kentucky firing a Trident II SLBM in 2015 as part of the DASO 26 test launch
USS Kentucky, an Ohio-class submarine of the US Navy
HMS Vigilant, a Vanguard-class submarine of the Royal Navy
Submarine-launched ballistic missile
A submarine-launched ballistic missile (SLBM) is a ballistic missile capable of being launched from submarines. Modern variants usually deliver multiple independently targetable reentry vehicles (MIRVs), each of which carries a nuclear warhead and allows a single launched missile to strike several targets. Submarine-launched ballistic missiles operate in a different way from submarine-launched cruise missiles.
A UGM-96 Trident I clears the water after launch from a US Navy submarine in 1984.
Polaris A-1
A Trident II missile just after launch.
Montage of the launch of a Trident I C-4 SLBM and the paths of its reentry vehicles