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, 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.
| UGM-133A Trident II | |
|---|---|
A Trident II launch from a submerged Royal Navy submarine. | |
| Type | SLBM |
| Place of origin | United States |
| Service history | |
| In service | 1990–present |
| Used by | United States Navy Royal Navy |
| Production history | |
| Manufacturer | Lockheed Martin Space |
| Unit cost | $30.9 million (2019) |
| Produced | 1983 |
| Specifications | |
| Mass | 130,000 lb (59,000 kg) |
| Length | 44 ft 6.6 in (13.579 m) |
| Diameter | 6 ft 11 in (2.11 m) (1st stage) |
| Warhead | 1–12 Mk-5 RV/W88 (475 kt) or 1–14 Mk-4 RV/W76-0 (100 kt) or 1–14 Mk-4A RV/W-76-1 or(90 kt) or unknown Mk-7 RV/W93 (unknown kt) Single or multiple W76-2 (5–7 kt) |
| Engine | Three solid-fuel rocket motors; first & second stage – Thiokol/Hercules solid-fueled rocket; third stage – United Technologies Corp. solid-fueled rocket |
| Propellant | NEPE-75: Nitrate ester, plasticized polyethylene glycol-bound HMX, Aluminum, ammonium perchlorate |
Operational range | More than 7,500 mi (12,000 km) (exact is classified) |
| Maximum speed | Approximately 18,030 mph (29,020 km/h) (Mach 24; 8,060 m/s) (terminal phase) |
Guidance system | MK 6 astro-inertial guidance which is able to receive Global Positioning System updates |
Steering system | Single movable nozzle actuated by a gas generator |
| Accuracy | 100 m |
Launch platform | Ballistic missile submarine |
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, 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, the most recent being from USS Maine (SSBN-741) in February 2020. There have been fewer than 10 test flights that were failures, the most recent being from HMS Vengeance off the coast of Florida in June 2016. 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.