W88

W88
Diagram of the W88 warhead: In 1999, information was released showing that in the W88, the primary (top) is egg-shaped, while the secondary (bottom) is spherical.
Type	Nuclear weapon
Service history
In service	1989 to present
Used by	United States Navy
Production history
Designer	Los Alamos National Laboratory
Designed	1970s to 1980s
Manufacturer	Rocky Flats
Produced	1988 to 1989 (full production)
No. built	~400
Specifications
Mass	175-360 kg[1][2]
Length	Approximately 60 inches (150 cm)[3]
Diameter	18 inches (46 cm)[3]
Detonation mechanism	Contact, airburst
Blast yield	475 kilotons of TNT (1,990 TJ)

The W88 is an American thermonuclear warhead, with an estimated yield of 475 kilotons of TNT (1,990 TJ),^[2] and is small enough to fit on MIRVed missiles. The W88 was designed at the Los Alamos National Laboratory in the 1970s. In 1999, the director of Los Alamos who had presided over its design described it as "the most advanced U.S. nuclear warhead".^[4] As of 2021, the latest version is called the W88 ALT 370,^[5] the first unit of which came into production on 1 July, 2021, after 11 years of development.^[6] The Trident II submarine-launched ballistic missile (SLBM) can be armed with up to eight W88 warheads (Mark 5 re-entry vehicle) or twelve 100 kt W76 warheads (Mark 4 re-entry vehicle), but it is limited to eight warheads under the Strategic Offensive Reductions Treaty.