UGM-133 Trident II
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,[6] 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,[14] and its high accuracy—approaching that of land-based missiles—enables it to be used as a first strike weapon.[15][16][17]
"Trident II" redirects here. For the French fighter plane, see SNCASO Trident.UGM-133A Trident II
United States
1990–present
$30.9 million (2019)[1]
1983
130,000 lb (59,000 kg)[2]
44 ft 6.6 in (13.579 m)
6 ft 11 in (2.11 m) (1st stage)[2]
Three solid-fuel rocket motors; first & second stage – Thiokol/Hercules solid-fueled rocket; third stage – United Technologies Corp. solid-fueled rocket[6]
NEPE-75:[7] Nitrate ester, plasticized polyethylene glycol-bound HMX, Aluminum, ammonium perchlorate
Approximately 18,030 mph (29,020 km/h) (Mach 24; 8,060 m/s)[2] (terminal phase)
MK 6 astro-inertial guidance which is able to receive Global Positioning System updates[2][11]
Single movable nozzle actuated by a gas generator
Trident II missiles are carried by 14 US Ohio and 4 British Vanguard-class submarines, with 24 missiles on each Ohio class and 16 missiles on each Vanguard class (the number of missiles on Ohio-class submarines was reduced to 20, by 2017,[18][19] in compliance with the New Strategic Arms Reduction Treaty). There have been 177 successful test flights of the D5 missile since design completion in 1989,[20] the most recent being from USS Maine (SSBN-741) in February 2020.[21] There have been fewer than 10 test flights that were failures,[22] the most recent being from HMS Vanguard off the coast of Florida in January 2024.[23] The D5 is the sixth in a series of missile generations deployed since the sea-based deterrent program began 60 years ago. The Trident D5LE (life-extension) version will remain in service until 2042.[24]
