UGM-133 Trident II, or Trident D5 is a submarine-launched ballistic missile, built by Lockheed Martin Space Systems in Sunnyvale, California, and deployed with the US and Royal Navies. It was first deployed in 1990, and is still in service. It is estimated that 540 missiles will be built by 2013. The Trident D5LE (life-extension) version will remain in service until 2042.