B61 bomb in various stages of assembly.

The B61 nuclear bomb is the primary thermonuclear weapon in the U.S. Enduring Stockpile following the end of the Cold War. In active service are the Mod 7 (up to 350 kilotons), Mod 10 (up to 170 kt), and Mod 11 (undisclosed yield). Image File history File linksMetadata B-61_bomb_(DOE). ... Image File history File linksMetadata B-61_bomb_(DOE). ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, in 1945 lifted nuclear fallout some 18 km (60,000 feet) above the epicenter. ... The mushroom cloud of the atomic bombing of Nagasaki, Japan, in 1945 lifted nuclear fallout some 18 km (60,000 feet) above the epicenter. ... Motto: Official (Latin): E pluribus unum (1789 to 1956) (Translated: Out of Many, One) In God We Trust (1956 to present) Anthem: The Star-Spangled Banner Capital Washington, D.C. Largest city New York City Official language(s) None at federal level; English de facto Government  â€¢ President  â€¢ Vice President Federal... The Enduring Stockpile is the name of the United Statess arsenal of nuclear weapons following the end of the Cold War. ... For the generic term for high-tension and / or indirect struggle between states, falling short of actual open hostilities, see cold war (war). ... A megaton or megatonne is a unit of mass equal to 1,000,000 metric tons, i. ... The explosive yield of a nuclear weapon is the amount of energy discharged when the weapon explodes, expressed in the equivalent mass of trinitrotoluene (TNT), either in kilotons (thousands of tons of TNT) or megatons (million of tons of TNT). ...

Development

The B61, originally known (prior to 1968) as the Mk 61, was designed in 1963. Testing began in 1966, with full production beginning in 1968. Total production of all versions was approximately 3,155, of which approximately 1,925 remain in service as of 2002. The warhead has changed little over the years, although early versions have been upgraded to improve their safety features. 1968 (MCMLXVIII) was a leap year starting on Monday (the link is to a full 1968 calendar). ... 1963 (MCMLXIII) was a common year starting on Tuesday (link will take you to calendar). ... 1966 (MCMLXVI) was a common year starting on Saturday (link goes to calendar) // Events January January 1 - In a coup, Colonel Jean-Bédel Bokassa ousts president David Dacko and takes over the Central African Republic. ... 1968 (MCMLXVIII) was a leap year starting on Monday (the link is to a full 1968 calendar). ... 2002 (MMII) was a common year starting on Tuesday of the Gregorian calendar. ...

The newest variant is the B61 Mod 11, deployed in 1997, which is a ground penetrating bunker buster. 1997 (MCMXCVII) is a common year starting on Wednesday of the Gregorian calendar. ... Bunker-busting nuclear weapons are a proposed type of nuclear weapon that would be designed to penetrate into soil, rock or concrete to deliver a low-yield nuclear warhead. ...

The B61 has been deployed by a very wide variety of U.S. military aircraft. Aircraft cleared for its use have included the B-1, B-2, B-52, and FB-111 strategic bomber aircraft; the F-100 Super Sabre, F-104 Starfighter, F-105 Thunderchief, F-111 and F-4 Phantom II fighter bombers; the A-4 Skyhawk, A-6 Intruder, and A-7 Corsair II attack aircraft; the F-15 Eagle and F-15E Strike Eagle, F-16, F/A-18 Hornet and Super Hornet; and the F-117. German and Italian Panavia Tornado IDS aircraft can also carry the B61. It is likely (although currently unconfirmed) that the F/A-22 Raptor and F-35 will be capable of employing the B61, likley on external pylons since the bomb is too large for either Aircraft's internal weapons bays, compromising their stealthiness. It is notable to mention that this is not the case the F-117. Military aircraft are airplanes used in warfare. ... It has been suggested that B-1R be merged into this article or section. ... The United States Air Force is the only agency in the world that operates the B-2 Spirit. ... A B-52 in flight The Boeing B-52 Stratofortress is a long-range strategic bomber flown by the United States Air Force since 1954, replacing the Convair B-36 and the Boeing B-47. ... A U.S. Air Force F-111 The General Dynamics F-111 was a long-range strategic bomber, reconnaissance, and tactical strike aircraft. ... A bomber is a military aircraft designed to attack ground targets, primarily by dropping bombs. ... The North American F-100 Super Sabre was a jet fighter aircraft that served with the USAF from 1954 to 1971 and with the ANG until 1979. ... The Lockheed F-104 Starfighter was a high-performance supersonic interceptor aircraft, capable of high speeds and climb rates. ... The Republic F-105 Thunderchief (commonly known as the Thud by its pilots) was a single-seat, supersonic fighter-bomber used by the United States Air Force. ... A U.S. Air Force F-111 The General Dynamics F-111 was a long-range strategic bomber, reconnaissance, and tactical strike aircraft. ... F-4 re-directs here; for alternate uses, see F4 The F-4 Phantom II (simply F-4 Phantom after 1990) is a two-place (tandem), supersonic, long-range, all-weather fighter-bomber built by (originally McDonnell Aircraft Corporation) McDonnell Douglas Corporation. ... A ground attack aircraft is an aircraft that is designed to operate very close to the ground, supporting infantry and tanks directly in battle. ... The A-4 Skyhawk is an attack aircraft originally designed to operate from United States Navy aircraft carriers. ... The Grumman A-6 Intruder is a US attack aircraft. ... A-7 Corsair II The Ling-Temco-Vought A-7 Corsair II was a light attack aircraft based on the F-8 Crusader. ... A ground attack aircraft is an aircraft that is designed to operate very close to the ground, supporting infantry and tanks directly in battle. ... An F-15 executing a zoom-climb takeoff in afterburner The Boeing (formerly McDonnell Douglas) F-15 Eagle is an American-built all-weather tactical fighter designed to gain and maintain air superiority in aerial combat. ... F-15E Strike Eagle The F-15E Strike Eagle is an American modern all-weather strike fighter, designed for long-range interdiction of enemy ground targets deep behind enemy lines. ... The F-16 Fighting Falcon is a modern multi-role jet fighter aircraft built in the United States and used by dozens of countries all over the world. ... April 2003: Two United States Navy F/A-18 Hornets prepare to launch from the flight deck of the aircraft carrier USS Harry S Truman. ... Four F/A-18 E/F Super Hornets assigned to the Black Aces of Strike Fighter Squadron Forty One (VFA-41) fly over the Western Pacific Ocean in a stack formation. ... The United States Air Forces F-117A Nighthawk is the worlds first operational aircraft designed to exploit low-observable stealth technology. ... The Panavia Tornado is a jet engine fighter-bomber and interceptor jointly developed as the Multi-role combat aircraft - or MRCA - by the United Kingdom, Germany and Italy. ... F/A-22 Raptors over California The F/A-22 Raptor is a highly maneuverable stealthy fighter aircraft built by Lockheed Martin Aeronautics and Boeing Integrated Defense Systems. ... The F-35 Joint Strike Fighter The F-35 Joint Strike Fighter (JSF) is a fighter plane currently in early development by Lockheed Martin (with partners Northrop Grumman and BAE SYSTEMS.) The primary customers are the United States armed forces and the United Kingdom (RN and RAF), but the Netherlands...

Approximately 480 are deployed with USAF units in the United Kingdom, Germany, and Turkey, 180 of which are held in U.S. custody for use by NATO squadrons in Belgium, Germany, Italy, the Netherlands, and Turkey under a nuclear weapons sharing agreement [1]. Seal of the Air Force. ... The NATO flag NATO 2002 Summit in Prague The North Atlantic Treaty Organisation (NATO), sometimes called North Atlantic Alliance, Atlantic Alliance or the Western Alliance, is an international organisation for defence collaboration established in 1949, in support of the North Atlantic Treaty signed in Washington, D.C., on April 4... Nuclear sharing is a concept in NATOs policy of nuclear deterrence, which involves member countries without nuclear weapons of their own in the planning for the use of nuclear weapons by NATO, and in particular provides for the armed forces of these countries to be involved in delivering these...

The B61 gravity bomb should not be confused with the MGM-1 Matador cruise missile, which originally was developed under the bomber designation B-61. Matador cruise missile launch The Matador was the first operational surface-to-surface cruise missile of the U.S. armed forces. ... A Tomahawk cruise missile A cruise missile indigenously made in Pakistan A cruise missile is a guided missile which uses a lifting wing and most often a jet propulsion system to allow sustained flight. ...

Design

A B61 bomb undergoing disassembly.

The B61 is a variable-yield bomb designed for carriage by high-speed aircraft. It has a streamlined casing capable of withstanding supersonic flight speeds. The weapon is 11 ft 8 in (3.58 m) long, with a diameter of about 13 in (33 cm). Basic weight is about 700 lb (317.5 kg), although the weights of individual weapons may vary depending on version and fuse/retardation configuration. B-61 gravity bomb from http://www. ... Dial-a-yield, an option available on most modern nuclear bombs, allows the operator to specify a bombs yield, or explosive power, allowing a single design to be used in different situations. ...

The newest variant is the B61 Mod 11, a hardened penetration bomb with a reinforced casing (according to some sources, containing depleted uranium) and a delayed-action fuse, allowing it to penetrate several metres into the ground before detonating, damaging fortified structures further underground [2]. The Mod 11 went into service in 1997 replacing the older megaton-yield B53 bomb, a limited number of which had been retained for anti-fortification use. About 50 Mod 11 bombs have been made, by converting Mod 7 bombs, to be primarily deployed by the B-2 Bomber. // Depleted uranium (DU) is uranium which contains a reduced proportion of the fissile isotope U-235. ... 1997 (MCMXCVII) is a common year starting on Wednesday of the Gregorian calendar. ... A megaton or megatonne is a unit of mass equal to 1,000,000 metric tons, i. ... The B53 was one of the most powerful nuclear weapons built by the United States, and one of the last very high-yield thermonuclear bombs in U.S. service. ... The B-2 Spirit, sometimes known as the B-2 Bomber, is an American multi_role stealth bomber capable of delivering both conventional and nuclear weapons. ...

Most versions of the B61 are equipped with a parachute retarder (currently a 24-ft (7.32 m) diameter nylon/Kevlar chute) to slow the weapon in its descent, giving the aircraft a chance to escape the blast (or to allow the weapon to survive impact with the ground in laydown mode). The B61 can be set for airburst, ground burst, or laydown detonation, and can be released at speeds up to Mach 2 and altitudes as low as 50 feet (15.24 m). Fusing for most versions is by radar. The Apollo 15 capsule landed safely despite a parachute failure. ... Kevlar (poly-paraphenylene terephthalamide) is the DuPont Company’s brand name for a synthetic material constructed of para-aramid fibers that the company claims is five times stronger than the same weight of steel, while being lightweight, flexible and comfortable. ... Laydown delivery is a mode of deploying a free-fall nuclear weapon in which the bombs fall is slowed by parachute so that it actually lands on the ground before detonating. ... An Air Burst occurs whenever an explosive device such as an anti-personnel artillery shell or a nuclear weapon is detonated in the air instead of on contact with the ground or target or a delayed armor peircing explosion. ... This long range radar antenna (approximately 40m (130ft) in diameter) rotates on a track to observe activities near the horizon. ...

The B61 is a variable-yield, kiloton-range weapon. Tactical versions (Mods 3, 4, and 10) can be set to 0.3, 1.5, 5, 10, 60, 80, or 170 kiloton explosive yield (depending on version). The strategic version (B61 Mod 7) has four yield options, with a maximum of 350 kilotons. The earth-penetrating Mod 11 apparently has a single, undisclosed yield. The early Mods 0, 1, 2, and 5 have been retired, and the Mod 10 has been moved to the inactive stockpile, leaving the Mods 3, 4, 7, and 11 as the only variants in active service. A megaton or megatonne is a unit of mass equal to 1,000,000 metric tons, i. ...

External links

• B61 information at Carey Sublette's NuclearWeaponArchive.org
• B61 information at GlobalSecurity.org
• "B61-11 Concerns and Background" from the Los Alamos Study Group, an anti-nuclear weapons organization
• "The B61 family of bombs" article by Robert S. Norris, Hans M. Kristensen, and Joshua Handler, in the Bulletin of the Atomic Scientists (2003)

The Bulletin of the Atomic Scientists is a journal concerned with global security issues, especially related to the dangers posed nuclear and other weapons of mass destruction. ...