Jacobs Engineering Group (United States) is involved in the joint venture AWE-ML. They are The AWE is responsible for warhead maintenance for the UK’s Trident II-nuclear arsenal. According to reports, the AWE facility is also developing a new warhead, the Mark 4A or Mk4A. The company is also part of the consortium responsible for the US nuclear weapons test site- Nevada National Security Site (NNSS) near Las Vegas.
Lockheed Martin (United States) is responsible for the construction of the Trident II (D5) nuclear missiles for the US and the UK. It is also involved in the production and maintenance of the Minuteman III nuclear intercontinental ballistic missiles for the US, and will now be developing the new Long Range Stand-Off (LRSO) missile. It is part of the team that manages the UK Atomic Weapons Establishment, that designs, manufactures and maintains nuclear warheads for the UK. It is also engaged in US nuclear weapons modernisation at the Pantex, Savannah River and Y-12 facilities.
Serco (United Kingdom) is part the joint venture AWE-ML, which runs the UK Atomic Weapons Establishment. It is responsible for manufacturing and maintaining Trident nuclear warheads for the UK arsenal, as well as developing the new Mark4A.