W87

W87. The W87 is an American thermonuclear warhead, originally designed for deployment on the LGM-118 Peacekeeper intercontinental ballistic missile. Developed by scientists at the Lawrence Livermore National Laboratory, it entered the United States nuclear arsenal in the late 1980s, representing a generation of warheads emphasizing high yield, safety, and reliability. Following the retirement of the Peacekeeper under the START II treaty, the warhead was adapted for use on the LGM-30G Minuteman III, a cornerstone of the U.S. land-based strategic deterrent.

Design and development

The design effort for the W87, led by the Lawrence Livermore National Laboratory, commenced in the early 1980s as part of the Missile Experimental (MX) program, which produced the LGM-118 Peacekeeper. Key objectives included achieving a high yield-to-weight ratio and incorporating advanced safety features known as Enhanced Nuclear Detonation Safety. The warhead's development occurred during a period of intense Cold War competition with the Soviet Union, paralleling advancements in Soviet systems like the RT-23 Molodets and the R-36M. The design leveraged previous weapons physics research and was tested, likely through underground experiments at the Nevada Test Site, before its production authorization in 1986.

Specifications

The W87-0 variant is reported to have a yield of 300 kilotons of TNT. It is a modern, two-stage thermonuclear device utilizing insensitive high explosives and advanced firing systems for improved safety. The warhead is encased in a Mark 21 re-entry vehicle, which is designed for high atmospheric re-entry speeds and accuracy. Its physical specifications, including weight and dimensions, are engineered for compatibility with both the Peacekeeper and Minuteman III missile buses. The later W87-1 modification is designed for a higher yield, estimated at 475 kilotons.

Deployment history

Full-scale production and deployment of the W87 on the LGM-118 Peacekeeper began in 1986, with each missile carrying up to ten warheads. The Peacekeeper was based primarily at F. E. Warren Air Force Base in Wyoming. With the ratification of the START I treaty and the signing of START II, which banned multiple independently targetable reentry vehicles on ICBMs, the Peacekeeper force was gradually retired, a process completed in 2005. Subsequently, a program was initiated to redeploy a limited number of W87 warheads on the LGM-30G Minuteman III, replacing older warheads like the W62 and W78 in the U.S. inventory.

Variants

Two primary variants of the warhead exist. The W87-0 is the original production model with a 300-kiloton yield, now deployed on the Minuteman III. The W87-1 is a modified version under development as part of the Nuclear Modernization Program, intended to have an increased yield of approximately 475 kilotons. The W87-1 is a key component of the program to replace the aging W78 warhead and is slated for use on the future LGM-35 Sentinel intercontinental ballistic missile. These modifications involve refurbishment and life-extension activities to ensure reliability for decades to come.

Role in nuclear deterrence

As a primary warhead on the LGM-30G Minuteman III, the W87 constitutes a critical element of the United States' nuclear triad, alongside weapons carried by B-2 Spirit bombers and Ohio-class submarines. Its accuracy, yield, and reliability underpin the strategy of assured retaliation central to U.S. policy. The ongoing modernization to the W87-1 variant, managed by the National Nuclear Security Administration, is a direct response to the evolving strategic environment and the modernization of rival arsenals, such as those of the Russian Federation and the People's Republic of China. This ensures the continued credibility of the American deterrent as outlined in documents like the Nuclear Posture Review.

Category:American nuclear warheads Category:Cold War nuclear weapons of the United States