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140-482: Operation Crossroads was a pair of nuclear weapon tests conducted by the United States at Bikini Atoll in mid-1946. They were the first nuclear weapon tests since Trinity on July 16, 1945, and the first detonations of nuclear devices since the atomic bombing of Nagasaki on August 9, 1945. The purpose of the tests was to investigate the effect of nuclear weapons on warships. The Crossroads tests were

280-399: A brigade ; however, over the course of the 19th and 20th centuries, the responsibilities of the rank expanded significantly. During the period from March 16, 1802, to January 11, 1812, the rank of major general was abolished and brigadier general became the highest rank in the U.S. Army. Foreseeing the need for an expanded general staff in case of war, which seemed imminent, Congress restored

420-513: A misnomer , as their energy comes from the nucleus of the atom, just as it does with fusion weapons. In fission weapons, a mass of fissile material ( enriched uranium or plutonium ) is forced into supercriticality —allowing an exponential growth of nuclear chain reactions —either by shooting one piece of sub-critical material into another (the "gun" method) or by compression of a sub-critical sphere or cylinder of fissile material using chemically fueled explosive lenses . The latter approach,

560-518: A nuclear explosion . Both bomb types release large quantities of energy from relatively small amounts of matter . The first test of a fission ("atomic") bomb released an amount of energy approximately equal to 20,000 tons of TNT (84  TJ ). The first thermonuclear ("hydrogen") bomb test released energy approximately equal to 10 million tons of TNT (42 PJ). Nuclear bombs have had yields between 10 tons TNT (the W54 ) and 50 megatons for

700-665: A policy of deliberate ambiguity , it does not acknowledge having them. Germany , Italy , Turkey , Belgium , the Netherlands , and Belarus are nuclear weapons sharing states. South Africa is the only country to have independently developed and then renounced and dismantled its nuclear weapons. The Treaty on the Non-Proliferation of Nuclear Weapons aims to reduce the spread of nuclear weapons, but there are different views of its effectiveness. There are two basic types of nuclear weapons: those that derive

840-696: A conference—called for in the manifesto—in Pugwash, Nova Scotia , Eaton's birthplace. This conference was to be the first of the Pugwash Conferences on Science and World Affairs , held in July 1957. By the 1960s, steps were taken to limit both the proliferation of nuclear weapons to other countries and the environmental effects of nuclear testing . The Partial Nuclear Test Ban Treaty (1963) restricted all nuclear testing to underground nuclear testing , to prevent contamination from nuclear fallout, whereas

980-458: A faster and less vulnerable attack, the development of long-range intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs) has given some nations the ability to plausibly deliver missiles anywhere on the globe with a high likelihood of success. More advanced systems, such as multiple independently targetable reentry vehicles (MIRVs), can launch multiple warheads at different targets from one missile, reducing

1120-614: A few nations possess such weapons or are suspected of seeking them. The only countries known to have detonated nuclear weapons—and acknowledge possessing them—are (chronologically by date of first test) the United States , the Soviet Union (succeeded as a nuclear power by Russia ), the United Kingdom , France , China , India , Pakistan , and North Korea . Israel is believed to possess nuclear weapons, though, in

1260-492: A fission bomb to initiate them. Such a device might provide a simpler path to thermonuclear weapons than one that required the development of fission weapons first, and pure fusion weapons would create significantly less nuclear fallout than other thermonuclear weapons because they would not disperse fission products. In 1998, the United States Department of Energy divulged that the United States had, "...made

1400-421: A fusion weapon as of January 2016 , though this claim is disputed. Thermonuclear weapons are considered much more difficult to successfully design and execute than primitive fission weapons. Almost all of the nuclear weapons deployed today use the thermonuclear design because it results in an explosion hundreds of times stronger than that of a fission bomb of similar weight. Thermonuclear bombs work by using

1540-505: A large number of targets widely dispersed over a large area. A quarter century earlier, in 1921, the Navy had suffered a public relations disaster when General Billy Mitchell 's bombers sank every target ship the Navy provided for the Project B ship-versus-bomb tests. The Strauss test would be designed to demonstrate ship survivability . In August 1945, Senator Brien McMahon , who within

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1680-406: A mark where the 27,000-ton battleship USS  Arkansas was. As with Able , any ships that remained afloat within 1,000 yards (900 m) of the detonation were seriously damaged, but this time the damage came from below, from water pressure rather than air pressure. The greatest difference between the two shots was the radioactive contamination of all the target ships by Baker . Regardless of

1820-472: A nation's economic electronics-based infrastructure. Because the effect is most effectively produced by high altitude nuclear detonations (by military weapons delivered by air, though ground bursts also produce EMP effects over a localized area), it can produce damage to electronics over a wide, even continental, geographical area. Research has been done into the possibility of pure fusion bombs : nuclear weapons that consist of fusion reactions without requiring

1960-537: A new nuclear strategy, one that is distinct from that which gave relative stability during the Cold War. Since 1996, the United States has had a policy of allowing the targeting of its nuclear weapons at terrorists armed with weapons of mass destruction . Robert Gallucci argues that although traditional deterrence is not an effective approach toward terrorist groups bent on causing a nuclear catastrophe, Gallucci believes that "the United States should instead consider

2100-425: A nuclear war between two nations would result in mutual annihilation. From this point of view, the significance of nuclear weapons is to deter war because any nuclear war would escalate out of mutual distrust and fear, resulting in mutually assured destruction . This threat of national, if not global, destruction has been a strong motivation for anti-nuclear weapons activism. Critics from the peace movement and within

2240-411: A nuclear weapon from another country by threatening nuclear retaliation is known as the strategy of nuclear deterrence . The goal in deterrence is to always maintain a second strike capability (the ability of a country to respond to a nuclear attack with one of its own) and potentially to strive for first strike status (the ability to destroy an enemy's nuclear forces before they could retaliate). During

2380-465: A nuclear weapon is a gravity bomb dropped from aircraft ; this was the method used by the United States against Japan in 1945. This method places few restrictions on the size of the weapon. It does, however, limit attack range, response time to an impending attack, and the number of weapons that a country can field at the same time. With miniaturization, nuclear bombs can be delivered by both strategic bombers and tactical fighter-bombers . This method

2520-409: A nuclear weapon to its target is an important factor affecting both nuclear weapon design and nuclear strategy . The design, development, and maintenance of delivery systems are among the most expensive parts of a nuclear weapons program; they account, for example, for 57% of the financial resources spent by the United States on nuclear weapons projects since 1940. The simplest method for delivering

2660-433: A nuclear weapon with suitable materials (such as cobalt or gold ) creates a weapon known as a salted bomb . This device can produce exceptionally large quantities of long-lived radioactive contamination . It has been conjectured that such a device could serve as a "doomsday weapon" because such a large quantity of radioactivities with half-lives of decades, lifted into the stratosphere where winds would distribute it around

2800-415: A one-star billet is two to four years. Other than voluntary retirement, statute sets a number of mandates for retirement. All brigadier generals must retire after five years in grade or 30 years of service, whichever is later, unless selected or appointed for promotion, or reappointed to grade to serve longer. Otherwise, all general and flag officers must retire the month after their 64th birthday. However,

2940-421: A policy of expanded deterrence, which focuses not solely on the would-be nuclear terrorists but on those states that may deliberately transfer or inadvertently leak nuclear weapons and materials to them. By threatening retaliation against those states, the United States may be able to deter that which it cannot physically prevent.". Graham Allison makes a similar case, arguing that the key to expanded deterrence

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3080-428: A rapidly expanding hot gas bubble that pushed against the water, generating a supersonic hydraulic shock wave which crushed the hulls of nearby ships as it spread out. Eventually it slowed to the speed of sound in water, which is one mile per second (1,600 m/s), five times faster than that of sound in air. On the surface, the shock wave was visible as the leading edge of a rapidly expanding ring of dark water, called

3220-425: A safe distance from the detonations. The drones could fly into radiation environments, such as Able's mushroom cloud , which would have been lethal to crew members. All the land-based detonation-sequence photographs were taken by remote control from tall towers erected on several islands of the atoll. In all, Bikini cameras took 50,000 still pictures and 1,500,000 feet (460,000 m) of motion picture film. One of

3360-447: A significant portion of their energy from fission reactions used to "trigger" fusion reactions, and fusion reactions can themselves trigger additional fission reactions. Only six countries—the United States , Russia , the United Kingdom , China , France , and India —have conducted thermonuclear weapon tests. Whether India has detonated a "true" multi-staged thermonuclear weapon is controversial. North Korea claims to have tested

3500-550: A substantial investment" in the past to develop pure fusion weapons, but that, "The U.S. does not have and is not developing a pure fusion weapon", and that, "No credible design for a pure fusion weapon resulted from the DOE investment". Nuclear isomers provide a possible pathway to fissionless fusion bombs. These are naturally occurring isotopes ( Hf being a prominent example) which exist in an elevated energy state. Mechanisms to release this energy as bursts of gamma radiation (as in

3640-561: A year would write the Atomic Energy Act and organize and chair the Congressional Joint Committee on Atomic Energy , made the first public proposal for such a test, but one designed to demonstrate the vulnerability rather than survivability of ships. He proposed dropping an atomic bomb on captured Japanese ships and suggested, "The resulting explosion should prove to us just how effective the atomic bomb

3780-587: Is O-7. It is equivalent to the rank of rear admiral (lower half) in the other United States uniformed services which use naval ranks . It is abbreviated as BG in the Army, BGen in the Marine Corps, and Brig Gen in the Air Force and Space Force. The Civil Air Patrol also uses this grade for its National Vice Commander and some past National commanders. The rank of brigadier general has existed in

3920-420: Is a thermonuclear weapon that yields a relatively small explosion but a relatively large amount of neutron radiation . Such a weapon could, according to tacticians, be used to cause massive biological casualties while leaving inanimate infrastructure mostly intact and creating minimal fallout. Because high energy neutrons are capable of penetrating dense matter, such as tank armor, neutron warheads were procured in

4060-456: Is analogous to identifying a criminal by fingerprints. "The goal would be twofold: first, to deter leaders of nuclear states from selling weapons to terrorists by holding them accountable for any use of their weapons; second, to give leaders every incentive to tightly secure their nuclear weapons and materials." According to the Pentagon's June 2019 " Doctrine for Joint Nuclear Operations " of

4200-403: Is coming up with ways of tracing nuclear material to the country that forged the fissile material. "After a nuclear bomb detonates, nuclear forensics cops would collect debris samples and send them to a laboratory for radiological analysis. By identifying unique attributes of the fissile material, including its impurities and contaminants, one could trace the path back to its origin." The process

4340-481: Is for the purpose of achieving different yields for different situations , and in manipulating design elements to attempt to minimize weapon size, radiation hardness or requirements for special materials, especially fissile fuel or tritium. Some nuclear weapons are designed for special purposes; most of these are for non-strategic (decisively war-winning) purposes and are referred to as tactical nuclear weapons . The neutron bomb purportedly conceived by Sam Cohen

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4480-503: Is no evidence that it is feasible beyond the military domain. However, the U.S. Air Force funded studies of the physics of antimatter in the Cold War , and began considering its possible use in weapons, not just as a trigger, but as the explosive itself. A fourth generation nuclear weapon design is related to, and relies upon, the same principle as antimatter-catalyzed nuclear pulse propulsion . Most variation in nuclear weapon design

4620-409: Is not a fusion bomb. In the boosted bomb, the neutrons produced by the fusion reactions serve primarily to increase the efficiency of the fission bomb. There are two types of boosted fission bomb: internally boosted, in which a deuterium-tritium mixture is injected into the bomb core, and externally boosted, in which concentric shells of lithium-deuteride and depleted uranium are layered on the outside of

4760-490: Is not clear that this has ever been implemented, and their plausible use in nuclear weapons is a matter of dispute. The other basic type of nuclear weapon produces a large proportion of its energy in nuclear fusion reactions. Such fusion weapons are generally referred to as thermonuclear weapons or more colloquially as hydrogen bombs (abbreviated as H-bombs ), as they rely on fusion reactions between isotopes of hydrogen ( deuterium and tritium ). All such weapons derive

4900-454: Is the primary means of nuclear weapons delivery; the majority of U.S. nuclear warheads, for example, are free-fall gravity bombs, namely the B61 , which is being improved upon to this day. Preferable from a strategic point of view is a nuclear weapon mounted on a missile , which can use a ballistic trajectory to deliver the warhead over the horizon. Although even short-range missiles allow for

5040-785: Is when used against the giant naval ships." On September 19, the Chief of the United States Army Air Forces (USAAF), General of the Army Henry H. Arnold , asked the Navy to set aside 10 of the 38 captured Japanese ships for use in the test proposed by McMahon. Meanwhile, the Navy proceeded with its own plan, which was revealed at a press conference on October 27 by the Commander in Chief, United States Fleet , Fleet Admiral Ernest King . It involved between 80 and 100 target ships, most of them surplus U.S. ships. As

5180-469: The 187th Infantry Brigade ). While separate brigades (e.g. the 187th, commanded by then-BG William Westmoreland in Korea) were traditionally commanded by brigadier generals, this practice has ceased in recent history. Today, an Army or Marine Corps "BG" or "BGen," respectively, typically serves as deputy commander to the commanding general of a division or division-sized units and assists in overseeing

5320-453: The 509th Bombardment Group on July 1, 1946. It detonated 520 feet (158 m) above the target fleet and caused less than the expected amount of ship damage because it missed its aim point by 2,130 feet (649 m). The second test was Baker . The bomb was known as Helen of Bikini and was detonated 90 feet (27 m) underwater on July 25, 1946. Radioactive sea spray caused extensive contamination. A third deep-water test named Charlie

5460-476: The Baker shot. Fire caused serious damage to ship #10, the aircraft carrier Saratoga , more than 1 mile (1.6 km) from the blast. For test purposes, all the ships carried sample amounts of fuel and ordnance, plus airplanes. Most warships carried a seaplane on deck which could be lowered into the water by crane, but Saratoga carried several airplanes with highly volatile aviation fuel , both on deck and in

5600-427: The Baker test proceeded on schedule. 57 guinea pigs, 109 mice, 146 pigs, 176 goats, and 3,030 white rats had been placed on 22 target ships in stations normally occupied by people. 35% of these animals died or were euthanised in the three months following the explosion: 10% were killed by the air blast, 15% were killed by radiation, and 10% were killed by the researchers as part of later study. The most famous survivor

5740-496: The Deputy Chief of Naval Operations for Special Weapons, Vice Admiral William H. P. Blandy , whom Parsons proposed for the role. This recommendation was accepted, and on January 11, 1946, President Harry S. Truman appointed Blandy as head of Army/Navy Joint Task Force One (JTF-1), which was created to conduct the tests. Parsons became Deputy Task Force Commander for Technical Direction. USAAF Major General William E. Kepner

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5880-537: The Manhattan Project which built the bombs, did not get the job. The Joint Chiefs of Staff decided that because the Navy was contributing the most men and materiel , the test should be headed by a naval officer. Commodore William S. "Deak" Parsons was a naval officer who had worked on the Manhattan Project and participated in the bombing of Hiroshima . He had been promoted to assistant to

6020-642: The Marshall Islands , arrived by seaplane from Kwajalein . Referring to Biblical stories which they had learned from Protestant missionaries, he compared them to "the children of Israel whom the Lord saved from their enemy and led into the Promised Land." He also claimed it was "for the good of mankind and to end all world wars." There was no signed agreement, but he reported by cable "their local chieftain , referred to as King Juda, arose and said that

6160-558: The National Cancer Institute . Amphibious target ships were beached on Bikini Island. A support fleet of more than 150 ships provided quarters, experimental stations, and workshops for most of the 42,000 men (more than 37,000 of whom were Navy personnel) and the 37 female nurses. Additional personnel were located on nearby atolls such as Eniwetok and Kwajalein. Navy personnel were allowed to extend their service obligation for one year if they wanted to participate in

6300-695: The Starfish Prime high-altitude nuclear test in 1962, an unexpected effect was produced which is called a nuclear electromagnetic pulse . This is an intense flash of electromagnetic energy produced by a rain of high-energy electrons which in turn are produced by a nuclear bomb's gamma rays. This flash of energy can permanently destroy or disrupt electronic equipment if insufficiently shielded. It has been proposed to use this effect to disable an enemy's military and civilian infrastructure as an adjunct to other nuclear or conventional military operations. By itself it could as well be useful to terrorists for crippling

6440-495: The Treaty on the Non-Proliferation of Nuclear Weapons (1968) attempted to place restrictions on the types of activities signatories could participate in, with the goal of allowing the transference of non-military nuclear technology to member countries without fear of proliferation. Brigadier general (United States) A brigadier general ranks above a colonel and below a major general . The pay grade of brigadier general

6580-554: The Tsar Bomba (see TNT equivalent ). A thermonuclear weapon weighing as little as 600 pounds (270 kg) can release energy equal to more than 1.2 megatonnes of TNT (5.0 PJ). A nuclear device no larger than a conventional bomb can devastate an entire city by blast, fire, and radiation . Since they are weapons of mass destruction , the proliferation of nuclear weapons is a focus of international relations policy. Nuclear weapons have been deployed twice in war , both by

6720-676: The Tsar Bomba of the USSR, which released an energy equivalent of over 50 megatons of TNT (210 PJ), was a three-stage weapon. Most thermonuclear weapons are considerably smaller than this, due to practical constraints from missile warhead space and weight requirements. In the early 1950s the Livermore Laboratory in the United States had plans for the testing of two massive bombs, Gnomon and Sundial , 1 gigaton of TNT and 10 gigatons of TNT respectively. Fusion reactions do not create fission products, and thus contribute far less to

6860-403: The base surge ) and outside the 1000-yard circle, escaped serious contamination and hull damage and was successfully decontaminated, repaired, and briefly returned to service. The Baker shot produced so many unusual phenomena that a conference was held two months later to standardize nomenclature and define new terms for use in descriptions and analysis. The underwater fireball took the form of

7000-424: The hafnium controversy ) have been proposed as possible triggers for conventional thermonuclear reactions. Antimatter , which consists of particles resembling ordinary matter particles in most of their properties but having opposite electric charge , has been considered as a trigger mechanism for nuclear weapons. A major obstacle is the difficulty of producing antimatter in large enough quantities, and there

7140-519: The hangars below. The fire was extinguished, and Saratoga was kept afloat for use in the Baker shot. As with Little Boy (Hiroshima) and Fat Man (Nagasaki), the Crossroads Able shot was an air burst . These were purposely detonated high enough in the air to prevent surface materials from being drawn into the fireball. The height-of-burst for the Trinity test was 100 feet (30 m);

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7280-614: The head of government or head of state . Despite controls and regulations governing nuclear weapons, there is an inherent danger of "accidents, mistakes, false alarms, blackmail, theft, and sabotage". In the late 1940s, lack of mutual trust prevented the United States and the Soviet Union from making progress on arms control agreements. The Russell–Einstein Manifesto was issued in London on July 9, 1955, by Bertrand Russell in

7420-410: The stratosphere and become part of the global, rather than the local, environment. Air bursts were officially described as "self-cleansing." There was no significant local fallout from Able . There was an intense transitory burst of fireball radiation lasting a few seconds. Many of the closer ships received doses of neutron and gamma radiation that could have been lethal to anyone on the ship, but

7560-436: The tropopause into the stratosphere , where the calm non-turbulent winds permit the debris to travel great distances from the burst, eventually settling and unpredictably contaminating areas far removed from the target of the explosion. There are other types of nuclear weapons as well. For example, a boosted fission weapon is a fission bomb that increases its explosive yield through a small number of fusion reactions, but it

7700-537: The "implosion" method, is more sophisticated and more efficient (smaller, less massive, and requiring less of the expensive fissile fuel) than the former. A major challenge in all nuclear weapon designs is to ensure that a significant fraction of the fuel is consumed before the weapon destroys itself. The amount of energy released by fission bombs can range from the equivalent of just under a ton to upwards of 500,000 tons (500 kilotons ) of TNT (4.2 to 2.1 × 10  GJ). All fission reactions generate fission products ,

7840-415: The "slick" for its resemblance to an oil slick. Close behind the slick was a visually more dramatic but less destructive whitening of the water surface called the "crack". When the gas bubble's diameter equaled the water depth, 180 feet (55 m), it hit the sea floor and the sea surface simultaneously. At the bottom, it created a shallow crater 30 feet (9 m) deep and 2,000 feet (610 m) wide. At

7980-409: The 1946 movie, Gilda . The Baker bomb was Helen of Bikini. This femme-fatale theme for nuclear weapons, combining seduction and destruction, is epitomized by the use in all languages, starting in 1946, of " bikini " as the name for a woman's two-piece bathing suit . The United States' test series summary table is here: United States' nuclear testing series . At 09:00 on July 1, 1946, Gilda

8120-586: The 1980s (though not deployed in Europe) for use as tactical payloads for US Army artillery shells (200 mm W79 and 155 mm W82 ) and short range missile forces. Soviet authorities announced similar intentions for neutron warhead deployment in Europe; indeed, they claimed to have originally invented the neutron bomb, but their deployment on USSR tactical nuclear forces is unverifiable. A type of nuclear explosive most suitable for use by ground special forces

8260-418: The Army and the Navy maneuvered for control of the tests, Assistant Secretary of War Howard C. Peterson observed, "To the public, the test looms as one in which the future of the Navy is at stake ... if the Navy withstands [the tests] better than the public imagines it will, in the public mind the Navy will have 'won. ' " The Army's candidate to direct the tests, Major General Leslie Groves , head of

8400-574: The Bikini Lagoon as the site for the two 1946 detonations, Able and Baker . The deep underwater test, Charlie , scheduled for early 1947, would take place in the ocean west of Bikini. Of the possible places given serious consideration, including Ecuador's Galápagos Islands , Bikini offered the most remote location with a large protected anchorage, suitable but not ideal weather, and a small, easily moved population. It had come under exclusive United States control on January 15, when Truman declared

8540-425: The Cold War, policy and military theorists considered the sorts of policies that might prevent a nuclear attack, and they developed game theory models that could lead to stable deterrence conditions. Different forms of nuclear weapons delivery (see above) allow for different types of nuclear strategies. The goals of any strategy are generally to make it difficult for an enemy to launch a pre-emptive strike against

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8680-535: The JTF-1 replied that "it is regretted that such ships as the USS ; New York cannot be spared." A series of three tests was recommended to study the effects of nuclear weapons on ships, equipment, and materiel. The test site had to be in territory controlled by the United States. The inhabitants would have to be evacuated, so it was best if it was uninhabited, or nearly so, and at least 300 miles (500 km) from

8820-594: The Japanese cruiser Sakawa , the battleship Nagato , and the German cruiser Prinz Eugen . The ships carried sample amounts of fuel and ammunition, plus scientific instruments to measure air pressure , ship movement, and radiation . The live animals on some of the target ships were supplied by the support ship USS  Burleson , which brought 200 pigs, 60 guinea pigs, 204 goats, 5,000 rats, 200 mice, and grains containing insects to be studied for genetic effects by

8960-494: The Joint Chiefs of Staffs website Publication, "Integration of nuclear weapons employment with conventional and special operations forces is essential to the success of any mission or operation." Because they are weapons of mass destruction, the proliferation and possible use of nuclear weapons are important issues in international relations and diplomacy. In most countries, the use of nuclear force can only be authorized by

9100-503: The Nuclear Age (1961) that mere possession of a nuclear arsenal was enough to ensure deterrence, and thus concluded that the spread of nuclear weapons could increase international stability . Some prominent neo-realist scholars, such as Kenneth Waltz and John Mearsheimer , have argued, along the lines of Gallois, that some forms of nuclear proliferation would decrease the likelihood of total war , especially in troubled regions of

9240-494: The President nominates an officer for appointment to fill that position. For all five uniformed services, because the grade of brigadier general is a permanent rank, the nominee may still be screened by an in-service promotion board. The rank does not expire when the officer vacates a one-star position. Tour length varies depending on the position, by statute, or when the officer receives a new assignment. The average tour length of

9380-483: The Secretary of Defense can defer a general or flag officer's retirement until the officer's 66th birthday and the President can defer it until the officer's 68th birthday. Because there are a finite number of General officer positions, one officer must retire before another can be promoted. As a result, General and flag officers typically retire well in advance of the statutory age and service limits, so as not to impede

9520-473: The Soviet Union's position against acceptance of the Acheson–Lilienthal Plan , which discussed possible methods for the international control of nuclear weapons and the avoidance of future nuclear warfare. At a March 22 cabinet meeting he said, "from the standpoint of international relations it would be very helpful if the test could be postponed or never held at all." He prevailed on Truman to postpone

9660-609: The U.S. military since the inception of the Continental Army in June 1775. To prevent mistakes in recognizing officers, a general order was issued on July 14, 1775, establishing that brigadier generals would wear a ribbon, worn across the breast, between coat and waistcoat, pink in color. Later, on June 18, 1780, it was prescribed that brigadier generals would instead wear a single silver star on each epaulette . At first, brigadier generals were infantry officers who commanded

9800-608: The USAAF detonated a plutonium implosion-type fission bomb nicknamed " Fat Man " over the Japanese city of Nagasaki . These bombings caused injuries that resulted in the deaths of approximately 200,000 civilians and military personnel . The ethics of these bombings and their role in Japan's surrender are to this day, still subjects of debate . Since the atomic bombings of Hiroshima and Nagasaki , nuclear weapons have been detonated over 2,000 times for testing and demonstration. Only

9940-777: The USAF AIR-2 Genie , the AIM-26 Falcon and US Army Nike Hercules . Missile interceptors such as the Sprint and the Spartan also used small nuclear warheads (optimized to produce neutron or X-ray flux) but were for use against enemy strategic warheads. Other small, or tactical, nuclear weapons were deployed by naval forces for use primarily as antisubmarine weapons. These included nuclear depth bombs or nuclear armed torpedoes. Nuclear mines for use on land or at sea are also possibilities. The system used to deliver

10080-444: The United States against the Japanese cities of Hiroshima and Nagasaki in 1945 during World War II . Nuclear weapons have only twice been used in warfare, both times by the United States against Japan at the end of World War II . On August 6, 1945, the United States Army Air Forces (USAAF) detonated a uranium gun-type fission bomb nicknamed " Little Boy " over the Japanese city of Hiroshima ; three days later, on August 9,

10220-662: The United States to be the sole trustee of all the Pacific islands captured from Japan during the war. The Navy had been studying test sites since October 1945 and was ready to announce its choice of Bikini soon after Truman's declaration. On February 6, the survey ship Sumner began blasting channels through the Bikini reef into the lagoon . The local residents were not told why. The 167 Bikini islanders first learned their fate four days later, on Sunday, February 10, when Navy Commodore Ben H. Wyatt, United States military governor of

10360-526: The United States. Small, two-man portable tactical weapons (somewhat misleadingly referred to as suitcase bombs ), such as the Special Atomic Demolition Munition , have been developed, although the difficulty of combining sufficient yield with portability limits their military utility. Nuclear warfare strategy is a set of policies that deal with preventing or fighting a nuclear war. The policy of trying to prevent an attack by

10500-544: The advice of the Secretary of Defense, the service secretary, and if applicable, the service's chief of staff or commandant. The President may nominate any eligible officer who is not on the recommended list if it serves in the interest of the nation, but this is uncommon. The Senate must then confirm the nominee before the officer can be promoted. Once the nominee is confirmed, they are promoted to that rank once they assume or hold an office that requires or allows an officer of that rank. For positions of office reserved by statute,

10640-456: The aim point for Able and was painted orange, with white gun barrels and gunwales , to make her stand out in the central cluster of target ships. There were eight ships within 400 yards (366 m) of it. Had the bomb exploded over the Nevada as planned, at least nine ships, including two battleships and an aircraft carrier, likely would have sunk. The actual detonation point, west-northwest of

10780-508: The air. The submarine USS  Skipjack was the only sunken ship successfully raised at Bikini. She was towed to California and sunk again, as a target ship off the coast, two years later. Three other ships, all in sinking condition, were towed ashore at Bikini and beached: attack transport USS  Fallon , ship #25; destroyer USS  Hughes , ship #27; and submarine USS  Dentuda , ship #24. Dentuda , with her crew safely away from their submarine, being submerged (thus avoiding

10920-533: The blast, shut their eyes, and cradle their arm across their face for additional protection. A few observers who disregarded the recommended precautions advised the others when the bomb detonated. Most shipboard observers reported feeling a slight concussion and hearing a disappointing little "poom". On July 26, 2016, the National Security Archive declassified and released the entire stock of footage shot by surveillance aircraft that flew over

11060-469: The cameras could shoot 1,000 frames per second. Before the first test, all personnel were evacuated from the target fleet and Bikini Atoll. They boarded ships of the support fleet, which took safe positions at least 10 nautical miles (19 km) east of the atoll. Test personnel were issued special dark glasses to protect their eyes, but a decision was made shortly before Able that the glasses might not be adequate. Personnel were instructed to turn away from

11200-485: The chance of a successful missile defense . Today, missiles are most common among systems designed for delivery of nuclear weapons. Making a warhead small enough to fit onto a missile, though, can be difficult. Tactical weapons have involved the most variety of delivery types, including not only gravity bombs and missiles but also artillery shells, land mines , and nuclear depth charges and torpedoes for anti-submarine warfare . An atomic mortar has been tested by

11340-435: The creation of nuclear fallout than fission reactions, but because all thermonuclear weapons contain at least one fission stage, and many high-yield thermonuclear devices have a final fission stage, thermonuclear weapons can generate at least as much nuclear fallout as fission-only weapons. Furthermore, high yield thermonuclear explosions (most dangerously ground bursts) have the force to lift radioactive debris upwards past

11480-455: The decision process. The prospect of mutually assured destruction might not deter an enemy who expects to die in the confrontation. Further, if the initial act is from a stateless terrorist instead of a sovereign nation, there might not be a nation or specific target to retaliate against. It has been argued, especially after the September 11, 2001, attacks , that this complication calls for

11620-567: The degree of damage, only nine surviving Baker target ships were eventually decontaminated and sold for scrap. The rest were sunk at sea after decontamination efforts failed. Prinz Eugen , ship #36, survived both the Able and Baker tests but was too radioactive to have leaks repaired. In September 1946 she was towed to Kwajalein Atoll , where she capsized in shallow water on December 22. She remains there today, with starboard propeller blades in

11760-421: The destroyer USS  Lamson , which sank, was farther away than seven ships that stayed afloat. Lamson was broadside to the blast, taking the full impact on her port side, while the seven closer ships were anchored with their sterns toward the blast, somewhat protecting the most vulnerable part of the hull. The only large ship inside the 1000-yard radius which sustained moderate rather than serious damage

11900-434: The device was mounted on a tower. It made a crater 6 feet (1.8 m) deep and 500 feet (150 m) wide, and there was some local fallout . The test was conducted in secret, and the world at large learned nothing about the radioactive fallout at the time. To be a true air burst with no local fallout, the Trinity height-of-burst needed to be 580 feet (180 m). With an air burst, the radioactive fission products rise into

12040-469: The energy of a fission bomb to compress and heat fusion fuel. In the Teller-Ulam design , which accounts for all multi-megaton yield hydrogen bombs, this is accomplished by placing a fission bomb and fusion fuel ( tritium , deuterium , or lithium deuteride ) in proximity within a special, radiation-reflecting container. When the fission bomb is detonated, gamma rays and X-rays emitted first compress

12180-414: The first of many nuclear tests held in the Marshall Islands and the first to be publicly announced beforehand and observed by an invited audience, including a large press corps . They were conducted by Joint Army/Navy Task Force One, headed by Vice Admiral William H. P. Blandy rather than by the Manhattan Project , which had developed nuclear weapons during World War II . A fleet of 95 target ships

12320-547: The first test for six weeks, from May 15 to July 1. For public consumption, the postponement was explained as an opportunity for more Congressional observers to attend during their summer recess. When Congressmen complained about the destruction of $ 450 million worth of target ships, Blandy replied that their true cost was their scrap value at $ 10 per ton, only $ 3.7 million. Veterans and legislators from New York and Pennsylvania requested to keep their namesake battleships as museum ships , as Texas had done with USS  Texas , but

12460-455: The fission bomb core. The external method of boosting enabled the USSR to field the first partially thermonuclear weapons, but it is now obsolete because it demands a spherical bomb geometry, which was adequate during the 1950s arms race when bomber aircraft were the only available delivery vehicles. The detonation of any nuclear weapon is accompanied by a blast of neutron radiation . Surrounding

12600-480: The following day. Some of the 114 press observers expressed disappointment at the effect on ships. The New York Times reported, prematurely, that "only two were sunk, one capsized, and eighteen damaged." The next day, the Times carried an explanation by Forrestal that "heavily built and heavily armored ships are difficult to sink unless they sustain underwater damage." The main cause of less-than-expected ship damage

12740-420: The fusion fuel, then heat it to thermonuclear temperatures. The ensuing fusion reaction creates enormous numbers of high-speed neutrons , which can then induce fission in materials not normally prone to it, such as depleted uranium . Each of these components is known as a "stage", with the fission bomb as the "primary" and the fusion capsule as the "secondary". In large, megaton-range hydrogen bombs, about half of

12880-535: The globe, would make all life on the planet extinct. In connection with the Strategic Defense Initiative , research into the nuclear pumped laser was conducted under the DOD program Project Excalibur but this did not result in a working weapon. The concept involves the tapping of the energy of an exploding nuclear bomb to power a single-shot laser that is directed at a distant target. During

13020-497: The grounds of the David Taylor Model Basin outside Washington, DC, dress rehearsals for Baker were conducted with dynamite and model ships in a pond named "Little Bikini." A fleet of 93 target vessels was assembled in Bikini Lagoon. At the center of the target cluster, the density was 20 ships per square mile (7.7 per km), three to five times greater than military doctrine would allow. The stated goal

13160-647: The island on board the LST-861 , with most moving to the Rongerik Atoll . In the 1950s, a series of large thermonuclear tests rendered Bikini unfit for subsistence farming and fishing because of radioactive contamination . Bikini remains uninhabited as of 2017, though it is occasionally visited by sport divers . Planners attempted to protect participants in the Operation Crossroads tests against radiation sickness , but one study showed that

13300-530: The life expectancy of participants was reduced by an average of three months. The Baker test's radioactive contamination of all the target ships was the first case of immediate, concentrated radioactive fallout from a nuclear explosion. Chemist Glenn T. Seaborg , the longest-serving chairman of the Atomic Energy Commission , called Baker "the world's first nuclear disaster." The first proposal to test nuclear weapons against naval warships

13440-496: The majority of their energy from nuclear fission reactions alone, and those that use fission reactions to begin nuclear fusion reactions that produce a large amount of the total energy output. All existing nuclear weapons derive some of their explosive energy from nuclear fission reactions. Weapons whose explosive output is exclusively from fission reactions are commonly referred to as atomic bombs or atom bombs (abbreviated as A-bombs ). This has long been noted as something of

13580-498: The mice were placed outside the expected lethal zone in order to study possible mutations in future generations. Although Gilda missed its target Nevada by nearly half a mile (800 meters), and it failed to sink or to contaminate the battleship, a crew would not have survived. Goat #119, tethered inside a gun turret and shielded by armor plate , received enough fireball radiation to die four days later of radiation sickness having survived two days longer than goat #53, which

13720-407: The midst of the Cold War. It highlighted the dangers posed by nuclear weapons and called for world leaders to seek peaceful resolutions to international conflict. The signatories included eleven pre-eminent intellectuals and scientists, including Albert Einstein , who signed it just days before his death on April 18, 1955. A few days after the release, philanthropist Cyrus S. Eaton offered to sponsor

13860-545: The military establishment have questioned the usefulness of such weapons in the current military climate. According to an advisory opinion issued by the International Court of Justice in 1996, the use of (or threat of use of) such weapons would generally be contrary to the rules of international law applicable in armed conflict, but the court did not reach an opinion as to whether or not the threat or use would be lawful in specific extreme circumstances such as if

14000-523: The miss was caused by a miscalculation by the crew. The mystery was never solved. There were other factors that made Able less spectacular than expected. Observers were much farther away than at the Trinity test , and the high humidity absorbed much of the light and heat. The battleship USS  Nevada , the only battleship to get underway at the Attack on Pearl Harbor in 1941, had been designated as

14140-408: The missiles before they land or implementing civil defense measures using early-warning systems to evacuate citizens to safe areas before an attack. Weapons designed to threaten large populations or to deter attacks are known as strategic weapons . Nuclear weapons for use on a battlefield in military situations are called tactical weapons . Critics of nuclear war strategy often suggest that

14280-616: The natives of Bikini were very proud to be part of this wonderful undertaking." On March 6, Wyatt attempted to stage a filmed reenactment of the February 10 meeting in which the Bikinians had given away their atoll. Despite repeated promptings and at least seven retakes, Juda confined his on-camera remarks to, "We are willing to go. Everything is in God's hands." The next day, LST-861 moved them and their belongings 128 miles (206 km) east to

14420-406: The nearest city. So that a B-29 Superfortress could drop a bomb, there had to be an airbase within 1,000 miles (1,600 km). To contain the target ships, it needed to have a protected anchorage at least 6 miles (10 km) wide. Ideally, it would have predictable weather patterns and be free of severe cold and violent storms. Predictable winds would avoid having radioactive material blown back on

14560-505: The nuclear test site just minutes after the bomb detonated. The footage can be seen on YouTube . Able and Baker are the first two letters of the Joint Army/Navy Phonetic Alphabet , used from 1941 until 1956. Alfa and Bravo are their counterparts in the current NATO phonetic alphabet . Charlie is the third letter in both systems. According to eyewitness accounts, the time of detonation for each test

14700-585: The ocean." In Baker on July 25, the weapon was suspended beneath landing craft LSM-60 anchored in the midst of the target fleet. Baker was detonated at 08:35, 90 feet (27 m) underwater, halfway to the bottom in water 180 feet (55 m) deep. No identifiable part of LSM-60 was ever found; it was presumably vaporized by the nuclear fireball. Ten ships were sunk, including the German heavy cruiser Prinz Eugen , which sank in December, five months after

14840-614: The permanent grade of brigadier general, eligible officers are screened by a promotion board consisting of general officers from their branch of service. This promotion board then generates a list of officers it recommends for promotion to general rank. This list is then sent to the service secretary and the Joint Chiefs for review before it can be sent to the President , through the Secretary of Defense , for consideration. The President nominates officers to be promoted from this list with

14980-499: The planning and coordination of a mission. A Marine Expeditionary Brigade (MEB), as the medium capability (and sized) scalable Marine Air Ground Task Force (MAGTF) with up to 20,000 Marines, is normally commanded by a Marine BGen. An Air Force brigadier general typically commands a large wing or serves as the deputy commander for a NAF . Additionally, one-star officers of all services may serve as high-level staff officers in large military organizations. U.S. law explicitly limits

15120-541: The rank of major general in January 1812. The insignia for a brigadier general is one silver star worn on the shoulder or collar, and has not changed since the creation of the rank two centuries ago. Since the Mexican–American War , however, the lower rank of colonel has been the normal rank appointed to command a brigade that is organic to a division ( e.g. , the 1st Brigade of the 94th Infantry Division , vice

15260-428: The remains of the split atomic nuclei. Many fission products are either highly radioactive (but short-lived) or moderately radioactive (but long-lived), and as such, they are a serious form of radioactive contamination . Fission products are the principal radioactive component of nuclear fallout . Another source of radioactivity is the burst of free neutrons produced by the weapon. When they collide with other nuclei in

15400-542: The results, Senator McMahon complained to Truman that the Navy should not be "solely responsible for conducting operations which might well indeed determine its very existence." Truman acknowledged that "reports were getting around that these tests were not going to be entirely on the level." He imposed a civilian review panel on Operation Crossroads to "convince the public it was objective." Pressure to cancel Operation Crossroads altogether came from scientists and diplomats. Manhattan Project scientists argued that further testing

15540-527: The ship to experience a 90% radiation reduction would still have received a lethal dose of 1,000 rems. In the assessment of the Bulletin of the Atomic Scientists : "a large ship, about a mile away from the explosion, would escape sinking, but the crew would be killed by the deadly burst of radiations from the bomb, and only a ghost ship would remain, floating unattended in the vast waters of

15680-515: The ships did not become radioactive. Neutron activation of materials in the ships was judged to be a minor problem by the standards of the time. One sailor on the support ship USS  Haven was found to be "sleeping in a shower of gamma rays" from an illegal metal souvenir he had taken from a target ship. Fireball neutrons had made it radioactive. Within a day nearly all the surviving target ships had been reboarded. The ship inspections, instrument recoveries, and moving and remooring of ships for

15820-435: The spray dome into a hollow cylinder or chimney of spray called the "column", 6,000 feet (1,800 m) tall and 2,000 feet (600 m) wide, with walls 300 feet (90 m) thick. Nuclear weapon A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions , either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb ), producing

15960-402: The surrounding material, the neutrons transmute those nuclei into other isotopes, altering their stability and making them radioactive. The most commonly used fissile materials for nuclear weapons applications have been uranium-235 and plutonium-239 . Less commonly used has been uranium-233 . Neptunium-237 and some isotopes of americium may be usable for nuclear explosives as well, but it

16100-498: The survival of the state were at stake. Another deterrence position is that nuclear proliferation can be desirable. In this case, it is argued that, unlike conventional weapons, nuclear weapons deter all-out war between states, and they succeeded in doing this during the Cold War between the U.S. and the Soviet Union . In the late 1950s and early 1960s, Gen. Pierre Marie Gallois of France, an adviser to Charles de Gaulle , argued in books like The Balance of Terror: Strategy for

16240-412: The target, was closer to the attack transport USS  Gilliam , in much less crowded water. In addition to the five ships that sank, fourteen were judged to have serious damage or worse, mostly as a result of the shock wave . All but three were located within 1,000 yards (900 m) of the detonation. Inside that radius, orientation to the bomb was a factor in shock wave impact. For example, ship #6,

16380-458: The task force personnel, and predictable ocean currents would allow material to be kept away from shipping lanes, fishing areas, and inhabited shores. Timing was critical because Navy manpower required to move the ships was being released from active duty as part of the post-World War II demobilization, and civilian scientists knowledgeable about atomic weapons were leaving federal employment for college teaching positions. On January 24, Blandy named

16520-443: The test and wrote President Truman about his objections to it, arguing that any data obtained from the test could be obtained more accurately and cheaply in a laboratory. Secretary of State James F. Byrnes , who a year earlier had told physicist Leo Szilard that a public demonstration of the bomb might make the Soviet Union "more manageable" in Europe, now argued the opposite: that further display of U.S. nuclear power could harden

16660-452: The test, because radioactivity prevented repairs to a leak in the hull. Photographs of Baker are unique among nuclear detonation pictures. The searing, blinding flash that usually obscures the target area took place underwater and was barely seen. The clear image of ships in the foreground and background gives a sense of scale. The large condensation cloud and the vertical water column are distinctive Baker shot features. One picture shows

16800-436: The test, thus "absent without leave" from its post on Sakawa and showing up about the same time other surviving pigs were captured. The high rate of test animal survival was due in part to the nature of single-pulse radiation. As with the two Los Alamos criticality accidents involving the earlier demon core , victims who were close enough to receive a lethal dose died, while those farther away recovered and survived. Also, all

16940-492: The tests and see an atomic bomb explode. The islands of the Bikini Atoll were used as instrumentation sites and, until Baker contaminated them, as recreation sites. Radio-controlled autopilots were installed in eight B-17 bombers, converting them into remote-controlled drones which were then loaded with automatic cameras, radiation detectors, and air sample collectors. Their pilots operated them from mother planes at

17080-413: The top, it pushed the water above it into a "spray dome", which burst through the surface like a geyser . Elapsed time since detonation was four milliseconds. During the first full second, the expanding bubble removed all the water within a 500-foot (150 m) radius and lifted two million tons of spray and seabed sand into the air. As the bubble rose at 2,500 feet per second (760 m/s), it stretched

17220-487: The total number of general officers who may be on active duty. The total number of active duty general officers is capped at 218 for the Army, 62 for the Marine Corps, 170 for the Air Force, and 21 for the Space Force. The President or Secretary of Defense may increase the number of slots for one branch, so long as they subtract an equal number from another. Some of these slots are reserved by statute. For promotion to

17360-399: The uninhabited Rongerik Atoll , to begin a permanent exile. Three Bikini families returned in 1974 but were evacuated again in 1978 because of radioactivity in their bodies from four years of eating contaminated food. As of 2022, the atoll remains unpopulated. To make room for the target ships, 100 short tons (90 t) of dynamite were used to remove coral heads from Bikini Lagoon. On

17500-446: The weapon system and difficult to defend against the delivery of the weapon during a potential conflict. This can mean keeping weapon locations hidden, such as deploying them on submarines or land mobile transporter erector launchers whose locations are difficult to track, or it can mean protecting weapons by burying them in hardened missile silo bunkers. Other components of nuclear strategies included using missile defenses to destroy

17640-631: The world where there exists a single nuclear-weapon state. Aside from the public opinion that opposes proliferation in any form, there are two schools of thought on the matter: those, like Mearsheimer, who favored selective proliferation, and Waltz, who was somewhat more non- interventionist . Interest in proliferation and the stability-instability paradox that it generates continues to this day, with ongoing debate about indigenous Japanese and South Korean nuclear deterrent against North Korea . The threat of potentially suicidal terrorists possessing nuclear weapons (a form of nuclear terrorism ) complicates

17780-624: The yield comes from the final fissioning of depleted uranium. Virtually all thermonuclear weapons deployed today use the "two-stage" design described to the right, but it is possible to add additional fusion stages—each stage igniting a larger amount of fusion fuel in the next stage. This technique can be used to construct thermonuclear weapons of arbitrarily large yield. This is in contrast to fission bombs, which are limited in their explosive power due to criticality danger (premature nuclear chain reaction caused by too-large amounts of pre-assembled fissile fuel). The largest nuclear weapon ever detonated,

17920-545: Was Deputy Task Force Commander for Aviation. Blandy codenamed the tests Operation Crossroads. Under pressure from the Army, Blandy agreed to crowd more ships into the immediate target area than the Navy wanted, but he refused USAAF Major General Curtis LeMay 's demand that "every ship must have a full loading of oil, ammunition, and fuel." Blandy's argument was that fires and internal explosions might sink ships that would otherwise remain afloat and be available for damage evaluation. When Blandy proposed an all-Navy board to evaluate

18060-552: Was Pig #311, which was reportedly found swimming in the lagoon after the blast and was brought back to the National Zoo in Washington, DC . The mysterious survival of Pig #311 caused some consternation at the time and has continued to be reported in error. However, an investigation pointed to the conclusion that it had neither swum in the ocean nor escaped the blast; it had likely been safely aboard an observation vessel during

18200-428: Was announced as H or How hour; in the official JTF-1 history, the term M or Mike hour is used instead. There were only seven nuclear bombs in existence in July 1946. The two bombs used in the test were Fat Man plutonium implosion-type nuclear weapons of the kind dropped on Nagasaki. The Able bomb was stenciled with the name Gilda and decorated with an Esquire magazine photograph of Rita Hayworth , star of

18340-474: Was assembled in Bikini Lagoon and hit with two detonations of Fat Man plutonium implosion-type nuclear weapons of the kind dropped on Nagasaki in 1945, each with a yield of 23 kilotons of TNT (96  TJ ). The first test was Able . The bomb was named Gilda after Rita Hayworth 's character in the 1946 film Gilda and was dropped from the B-29 Superfortress Dave's Dream of

18480-627: Was dropped from the B-29 Dave's Dream of the 509th Bombardment Group . The plane, formerly known as Big Stink , had been the photographic equipment aircraft on the Nagasaki mission in 1945. It had been renamed in honor of Dave Semple , a bombardier who was killed during a practice mission on March 7, 1946. Gilda detonated 520 feet (158 m) above the target fleet, with a yield of 23 kilotons. Five ships were sunk. Two attack transports sank immediately, two destroyers within hours, and Sakawa

18620-520: Was made on August 16, 1945, by Lewis Strauss , future chairman of the Atomic Energy Commission . In an internal memo to Secretary of the Navy James Forrestal , Strauss argued, "If such a test is not made, there will be loose talk to the effect that the fleet is obsolete in the face of this new weapon and this will militate against appropriations to preserve a postwar Navy of the size now planned." With very few bombs available, he suggested

18760-579: Was not to duplicate a realistic anchorage but to measure damage as a function of distance from the blast center, at as many distances as possible. The arrangement also reflected the outcome of the Army/Navy disagreement about how many ships should be allowed to sink. The target fleet included four obsolete U.S. battleships, two aircraft carriers , two cruisers , thirteen destroyers , eight submarines , forty landing ships, eighteen transports, two oilers, one floating drydock, and three surrendered Axis ships,

18900-438: Was on the deck, unshielded. Had Nevada been fully manned, she would likely have become a floating coffin, dead in the water for lack of a live crew. Two years later she was finished off by an aerial torpedo 65 miles southwest of Pearl Harbor on 31 July 1948. In theory, every unprotected location on the ship received 10,000 rems (100 Sv) of initial nuclear radiation from the fireball. Therefore, people deep enough inside

19040-483: Was planned for 1947 but was canceled primarily because of the United States Navy 's inability to decontaminate the target ships after the Baker test. Ultimately, only nine target ships were able to be scrapped rather than scuttled . Charlie was rescheduled as Operation Wigwam , a deep-water shot conducted in 1955 off the coast of Mexico ( Baja California ). Bikini's native residents were evacuated from

19180-554: Was that the bomb missed its aim point by 710 yards (649 m). The ship the bomb was aimed at failed to sink. The miss resulted in a government investigation of the flight crew of the B-29 bomber. Various explanations were offered, including the bomb's known poor ballistic characteristics, but none was convincing. Images of the drop were inconclusive. The bombsight was checked and found error free. Pumpkin bomb drops were conducted and were accurate. Colonel Paul W. Tibbets believed that

19320-744: Was the Special Atomic Demolition Munition , or SADM, sometimes popularly known as a suitcase nuke . This is a nuclear bomb that is man-portable, or at least truck-portable, and though of a relatively small yield (one or two kilotons) is sufficient to destroy important tactical targets such as bridges, dams, tunnels, important military or commercial installations, etc. either behind enemy lines or pre-emptively on friendly territory soon to be overtaken by invading enemy forces. These weapons require plutonium fuel and are particularly "dirty". They also demand especially stringent security precautions in their storage and deployment. Small "tactical" nuclear weapons were deployed for use as antiaircraft weapons. Examples include

19460-502: Was the sturdily built Japanese battleship Nagato , ship #7, whose stern-on orientation to the bomb gave her some protection. Unrepaired damage from World War II may have complicated damage analysis. As the ship from which the Pearl Harbor attack had been commanded, Nagato was positioned near the aim point to guarantee her being sunk. The Able bomb missed its target, and the symbolic sinking came three weeks later, five days after

19600-473: Was unnecessary and environmentally dangerous. A Los Alamos study warned "the water near a recent surface explosion will be a witch's brew" of radioactivity. When the scientists pointed out that the tests might demonstrate ship survivability while ignoring the effect of radiation on sailors, Blandy responded by adding test animals to some of the ships, thereby generating protests from animal rights advocates. J. Robert Oppenheimer declined an invitation to attend

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