Tsar Bomba

In the mid-1950s, the United States had an unconditional superiority over the USSR in nuclear weapons, although thermonuclear charges had already been created in the USSR at this time. Also, there were no effective means of delivering nuclear warheads to the United States, both in the 1950s and in 1961. The USSR did not have a real possibility of a retaliatory nuclear strike against the USA.[14]

In addition to foreign policy and propaganda considerations to respond to US nuclear blackmail, the creation of "Tsar Bomba" fit into the concept of nuclear deterrence, adopted during the leadership of G.M. Malenkov and N. S. Khrushchev. It boiled down to a nuclear bluff to create the appearance of nuclear equilibrium.[15]

Also on June 23, 1960, the Resolution of the Council of Ministers of the USSR was issued on the creation of a super-heavy ballistic missile N-1 ( GRAU index – 11A52) with a warhead weighing 75 tons (for a comparative assessment – the weight of the warhead tested in 1964 by the UR-500 intercontinental ICBM was 14 -tons).[16]

The development of new designs of nuclear and thermonuclear ammunition requires testing. The operability of the device must be confirmed, its safety in emergency situations, and the calculated energy release during an explosion must be confirmed.[17]

Before the bomb, in the early 1950s, a similar torpedo was being developed. At that time, there were no aviation and missile systems with the necessary tactical and technical characteristics in the USSR, and the country's leadership decided to create a thermonuclear torpedo and a submarine to deliver it to the enemy's coast: on September 12, 1952, J.V. Stalin signed a decree of the USSR Council of Ministers "On the design and construction of facility 627" (nuclear powered submarine). It was assumed that it would be the carrier of the T-15 torpedo with a thermonuclear charge with a capacity of up to 100 megatons of TNT equivalent. Due to unsuccessful tests, the T-15 was not completed, and the submarine received conventional torpedoes.[18]

A Tsar Bomba-type casing on display at Sarov

Official names: "product 602", "AN602", "Ivan."[19]

At present, the difference in names becomes the cause of confusion, when AH602 is mistakenly identified with RDS-37 or with PH202 (product 202). (The AH602 was a modification of the RN202.[12] In the correspondence for the RN202, the designation RDS-202,[20] “202,”[21] and “Product B,”[22] were originally used.)

Unofficial names – "Tsar Bomba" and "Kuzkina Mother." The name "Tsar Bomba" emphasizes that this is the most powerful weapon in history. The name “Kuz'kina's Mother” was inspired by the statement of N. S. Khrushchev to US Vice President Richard Nixon: “We have funds at our disposal that will have dire consequences for you. We will show you Kuzkin's mother!"[23][24]

The CIA designated the bomb or the test as "JOE 111."[8]

The development of a super-powerful bomb began in 1956[25] and was carried out in two stages. At the first stage, from 1956 to 1958, it was "product 202," which was developed in the recently created NII-1011. The modern name of NII-1011 is the "Russian Federal Nuclear Center – All-Russian Scientific Research Institute Of Technical Physics ( RFNC-VNIITF )." According to the official history of the institute, the order on the creation of a research institute in the system of the USSR Ministry of Medium Machine Building was signed on April 5, 1955; work at the NII-1011 began a little later.

At the second stage of development, from 1960 to a successful test in 1961, the bomb was called "item 602" and was developed at KB-11 (now – VNIIEF ), V. B. Adamsky was developing,[25] and besides him, the physical scheme was developed by A. D. Sakharov, Yu. N. Babaev, Yu. N. Smirnov, Yu. A. Trutnev.[14]

The initial three-stage design of Tsar Bomba was capable of yielding approximately 100 Mt (420 PJ) through fast fission (3,000 times the size of the Hiroshima and Nagasaki bombs);[38] however, it was thought that this would have resulted in too much nuclear fallout, and the aircraft delivering the bomb would not have had enough time to escape the explosion. To limit the amount of fallout, the third stage and possibly the second stage had a lead tamper instead of a uranium-238 fusion tamper (which greatly amplifies the fusion reaction by fissioning uranium atoms with fast neutrons from the fusion reaction). This eliminated fast fission by the fusion-stage neutrons so that approximately 97% of the total yield resulted from thermonuclear fusion alone (as such, it was one of the "cleanest" nuclear bombs ever created, generating a very low amount of fallout relative to its yield).[39] There was a strong incentive for this modification since most of the fallout from a test of the bomb would likely have descended on populated Soviet territory.[34][40]

The first studies on "Topic 242" began immediately after Igor Kurchatov talked with Andrei Tupolev (then held in Autumn 1954). Tupolev appointed his deputy for weapon systems, Aleksandr Nadashkevich, as the head of the Topic. Subsequent analysis indicated that to carry such a heavy, concentrated load, the Tu-95 bomber carrying the Tsar Bomba needed to have its engines, bomb bay, suspension and release mechanisms seriously redesigned. The Tsar Bomba's dimensional and weight drawings were passed in the first half of 1955, together with its placement layout drawing. The Tsar Bomba's weight accounted for 15% the weight of its Tu-95 carrier as expected. The carrier, aside from having its fuel tanks and bomb bay doors removed, had its BD-206 bomb-holder replaced by a new, heavier beam-type BD7-95-242 (or BD-242) holder attached directly to the longitudinal weight-bearing beams. The problem of how to release the bomb was also solved; the bomb-holder would release all three of its locks in a synchronous fashion via electro-automatic mechanisms as required by safety protocols.

A Joint Resolution of the CPSU Central Committee and the Council of Ministers (Nr. 357-28ss) was issued on 17 March 1956 which mandated that OKB-156 begin conversion of a Tu-95 bomber into a high-yield nuclear bomb carrier. These works were carried out in the Gromov Flight Research Institute from May to September 1956. The converted bomber, designated the Tu-95V, was accepted for duty and was handed over for flight tests which, including a release of a mock-up "superbomb," were conducted under the command of Colonel S. M. Kulikov until 1959 and passed without major issues.

Despite the creation of the Tu-95V bomb-carrier aircraft, the actual test of the Tsar Bomba was postponed for political reasons; namely Khrushchev's visit to the United States and a pause in the Cold War. The Tu-95V during this period was flown to Uzin (situated in today's Ukraine) and was used as a training aircraft, therefore it was no longer listed as a combat aircraft. With the beginning of a new round of the Cold War in 1961 the test was resumed. The Tu-95V had all connectors in its automatic release mechanism replaced, the bomb bay doors removed and the aircraft itself covered with a special reflective white paint.

In the fall of 1961, the aircraft was modified for testing AN602 at the Kuibyshev aircraft plant.[14]

Site of the detonation

Khrushchev personally announced the upcoming tests of a 50-megaton bomb in his report on October 17, 1961 at the XXII Congress of the CPSU.[41] Before the official announcement, in a casual conversation, he told an American politician about the bomb, and this information was published on September 8, 1961 in the "New York Times."[40] The Tsar Bomba was tested on 30 October 1961.

The Tu-95V aircraft No. 5800302 with a bomb on board took off from the Olenya airfield and was flown to State Test Site No. 6 of the USSR Ministry of Defense located on Novaya Zemlya[41] by Major Andrei Durnovtsev. The crew of the carrier aircraft consisted of nine people:[14]

• Test Pilot – Major Andrey Egorovich Durnovtsev
• Lead navigator of tests – Major Ivan Nikiforovich Kleshch
• Second pilot – Captain Mikhail Konstantinovich Kondratenko
• Navigator-operator of the radar – Lieutenant Anatoly Sergeevich Bobikov
• Radar operator – Captain Alexander Filippovich Prokopenko
• Flight engineer – Captain Grigory Mikhailovich Yevtushenko
• Radio operator – Lieutenant Mikhail Petrovich Mashkin
• Gunner-radio operator – Captain Vyacheslav Mikhailovich Snetkov
• Gunner-radio operator – Corporal Vasily Yakovlevich Bolotov

The test was also attended by the Tu-16A laboratory aircraft no. 3709 (which was equipped for monitoring the tests), and its crew:[14]

• Leading test pilot – Lieutenant Colonel Vladimir Fyodorovich Martynenko
• Second pilot – Senior Lieutenant Vladimir Ivanovich Mukhanov
• Leading navigator – Major Semyon Artemievich Grigoryuk
• Navigator-operator of the radar – Major Vasily Timofeevich Muzlanov
• Gunner-radio operator – Senior Sergeant Mikhail Emelyanovich Shumilov

Both aircraft were painted with the special reflective paint to minimize heat damage. Despite this effort, Durnovtsev and his crew were given only a 50% chance of surviving the test.[42][43]

The bomb, weighing 27 metric tons, was so large (8 metres (26 ft) long by 2.1 metres (6 ft 11 in) in diameter) that the Tu-95V had to have its bomb bay doors and fuselage fuel tanks removed.[1][43] The bomb was attached to an 800-kilogram (1,800 lb), 1,600-square-metre (17,000 sq ft) parachute, which gave the release and observer planes time to fly about 45 kilometres (28 mi) away from ground zero, giving them a 50 percent chance of survival.[38] The bomb was released two hours after takeoff from a height of 10,500 m (34,500 ft) on a test target within Sukhoy Nos. The Tsar Bomba detonated at 11:32 (or 11:33) Moscow Time on 30 October 1961, over the Mityushikha Bay nuclear testing range (Sukhoy Nos Zone C), north of the Arctic Circle over the Novaya Zemlya archipelago in the Arctic Ocean, at a height of 4,200 m ASL (4000 m above the target)[6][34][40] (some sources suggest 3,900 m ASL and 3,700 m above target, or 4,500 m). By this time the Tu-95V had already escaped to 39 km (24 mi) away, and the Tu-16 53.5 km (33.2 mi) away. When detonation occurred, the shock wave caught up with the Tu-95V at a distance of 115 km (71 mi) and the Tu-16 at 205 km (127 mi). The Tu-95V dropped 1 kilometre (0.62 mi) in the air because of the shock wave but was able to recover and land safely.[42] According to initial data, the Tsar Bomba had a nuclear yield of 58.6 Mt (245 PJ) (significantly exceeding what the design itself would suggest) and was overestimated at values all the way up to 75 Mt (310 PJ).

The Tsar Bomba's fireball, about 8 km (5.0 mi) wide at its maximum, was prevented from touching the ground by the shock wave, but nearly reached 10.5 km (6.5 mi) altitude in the sky – the altitude of the deploying Tu-95 bomber

Although simplistic fireball calculations predicted the fireball would hit the ground, the bomb's own shock wave bounced back and prevented this.[44] The 8-kilometre-wide (5.0 mi) fireball reached nearly as high as the altitude of the release plane and was visible at almost 1,000 km (620 mi) away from where it ascended.[45] The mushroom cloud was about 67 km (42 mi) high[46] (over seven times the height of Mount Everest), which meant that the cloud was above the stratosphere and well inside the mesosphere when it peaked. The cap of the mushroom cloud had a peak width of 95 km (59 mi) and its base was 40 km (25 mi) wide.[47]

According to a witness to the explosion, a Soviet cameraman said:

“The clouds beneath the aircraft and in the distance were lit up by the powerful flash. The sea of light spread under the hatch and even clouds began to glow and became transparent. At that moment, our aircraft emerged from between two cloud layers and down below in the gap a huge bright orange ball was emerging. The ball was powerful and arrogant like Jupiter. Slowly and silently it crept upwards... Having broken through the thick layer of clouds it kept growing. It seemed to suck the whole Earth into it. The spectacle was fantastic, unreal, supernatural.”[43]

The explosion of AN602, according to the classification of nuclear explosions, was an ultra-high power low air nuclear explosion. The results were impressive:

• The flare was visible at a distance of more than 1000 km.[48] It was observed in Norway, Greenland and Alaska.[14]
• The explosion's nuclear mushroom rose to a height of 67 kilometers.[12] The shape of the "hat" was two-tiered; the diameter of the upper tier was estimated at 95 kilometers, the lower tier at 70 kilometers. The cloud was observed 800 km from the explosion site.[14]
• The blast wave circled the globe three times,[14] with the first one taking 36 hours and 27 minutes.[13]
• A seismic wave in the earth's crust, generated by the shock wave of the explosion, circled the globe three times.[48]
• The atmospheric pressure wave resulting from the explosion was recorded three times in New Zealand: the station in Wellington recorded an increase in pressure at 21:57 on October 30 (coming from the north-west), at 07:17 on October 31 ( from the southeast) and at 9:16 on November 1 (from the northwest(GMT time)), with amplitudes of 0.6, 0.4 and 0.2 millibars. Respectively, the average wave speed is estimated at 303 m/s, or 9.9 degrees of the great circle per hour.[49]
• Glass shattered in windows 780 km from the explosion in a village on Dikson Island.[14]
• The sound wave generated by the explosion reached Dikson Island at a distance of about 800 kilometers, but there are no reports of destruction or damage to structures even in the urban-type settlement of Amderma, which is much closer (280 km) to the landfill.[50]
• Ionization of the atmosphere caused interference to radio communications even hundreds of kilometers from the test site for about 40 minutes.[51]
• Radioactive contamination of the experimental field with a radius of 2–3 km in the epicenter area was no more than 1 milliroentgen / hour, the testers appeared at the explosion site 2 hours later, radioactive contamination posed practically no danger to the test participants.[14]

All buildings in the village of Severny (both wooden and brick), located 55 km (34 mi) from ground zero within the Sukhoy Nos test range, were destroyed. In districts hundreds of kilometres from ground zero, wooden houses were destroyed, stone ones lost their roofs, windows, and doors, and radio communications were interrupted for almost one hour. One participant in the test saw a bright flash through dark goggles and felt the effects of a thermal pulse even at a distance of 270 km (170 mi). The heat from the explosion could have caused third-degree burns 100 km (62 mi) away from ground zero. A shock wave was observed in the air at Dikson settlement 700 km (430 mi) away; windowpanes were partially broken for distances up to 900 kilometres (560 mi).[52] Atmospheric focusing caused blast damage at even greater distances, breaking windows in Norway and Finland.[53] Despite being detonated 4.2 kilometres (2.6 mi) above ground, its seismic body wave magnitude was estimated at 5.0–5.25.[42][44]

Immediately after the test, several U.S. Senators condemned the Soviet Union. Prime Minister of Sweden, Tage Erlander saw the blast as the Soviets' answer to a personal appeal to halt nuclear testing that he had sent the Soviet leader in the week prior to the blast.[54] The British Foreign Office, Prime Minister of Norway Einar Gerhardsen, Prime Minister of Denmark Viggo Kampmann and others also released statements condemning the blast. Russian and Chinese radio stations mentioned the American underground nuclear test of a much smaller bomb (possibly the Mink test) carried out the day prior, without mentioning the Tsar Bomba test.[55]

The creation and testing of a superbomb was of great political importance: the Soviet Union demonstrated its potential in creating a nuclear arsenal of great power (at that time, the most powerful thermonuclear charge tested by the United States was 15 Mt). After the AN602 test, the United States did not increase the power of their own thermonuclear tests, and that in 1963 in Moscow the Treaty Banning Nuclear Weapon Tests in the Atmosphere, Outer Space and Under Water was signed.[14]

The scientific result of the test was the experimental verification of the principles of calculation and design of multistage thermonuclear charges. It was experimentally proven that there is no fundamental limitation on increasing the power of a thermonuclear charge (however, as early as October 30, 1949, three years before the Ivy Mike test, in the Supplement to the official report of the General Advisory Committee of the US Atomic Energy Commission, nuclear physicists Enrico Fermi and Isidor Isaac Rabi noted that thermonuclear weapons have "unlimited destructive power" and that the cost of increasing the yield of the munition in 1950 financial year prices was 60 cents per kiloton of TNT.)[56] In the tested specimen of the bomb, to raise the explosion power by another 50 megatons, it was enough to replace the lead sheath with uranium-238, as was normally expected.[35] The replacement of the cladding material and the decrease in the explosion power were motivated by the desire to reduce the amount of radioactive fallout to an acceptable level,[14] and not by the desire to reduce the weight of the bomb, as is sometimes believed (the weight of the AN602 really decreased from this, but insignificantly – the uranium cladding was supposed to weigh about 2800 kg, the lead sheath of the same volume – based on the lower density of lead – is about 1700 kg. The resulting relief of just over one ton is weakly noticeable with a total mass of AN602 of at least 24 tons and did not affect the state of affairs with its transportation.

The explosion has become one of the cleanest in the history of atmospheric nuclear tests per unit of power. The first stage of the bomb was a uranium charge with a capacity of 1.5 megatons,[35] which in itself provided a large amount of radioactive fallout, nevertheless, it can be assumed that AN602 was really relatively clean – more than 97% of the explosion power was provided by a thermonuclear fusion reaction, which practically does not create radioactive contamination.[57]

A distant consequence was the increased radioactivity accumulated in the glaciers of Novaya Zemlya. According to the 2015 expedition, due to nuclear tests, the glaciers of Novaya Zemlya are 65–130 times more radioactive than the background in neighboring areas, including due to the tests of the Kuz'kina Mother.[58]

Total destruction radius, superimposed on Paris. Red circle = total destruction (radius 35 kilometers), yellow circle = fireball (radius 3.5 kilometers).

The Tsar Bomba was the single most physically powerful device ever deployed on Earth.[59] For comparison, the largest weapon ever produced by the U.S., the now-decommissioned B41, had a predicted maximum yield of 25 megatons of TNT (100 PJ). The largest nuclear device ever tested by the U.S. (Castle Bravo) yielded 15 megatons of TNT (63 PJ) because of an unexpectedly high involvement of lithium-7 in the fusion reaction; the preliminary prediction for the yield was from 4 to 6 megatons of TNT (17 to 25 PJ). The largest weapons deployed by the Soviet Union were also around 25 megatons of TNT (100 PJ) (e.g., the SS-18 Mod. 3 warhead).[1]

The weight and size of the Tsar Bomba limited the range and speed of the specially modified bomber carrying it. Delivery by an intercontinental ballistic missile would have required a much stronger missile (the Proton started its development as that delivery system). It has been estimated that detonating the original 100 Mt design would have released fallout amounting to about 26% of all fallout emitted since the invention of nuclear weapons.[60] It was decided that a full 100 Mt detonation would create a nuclear fallout that was unacceptable in terms of pollution from a single test, as well as a near certainty that the release plane and crew would be destroyed before it could escape the blast radius.[61]

The Tsar Bomba was the culmination of a series of high-yield thermonuclear weapons designed by the Soviet Union and the United States during the 1950s (e.g., the Mark 17[62] and B41 nuclear bombs).[1]

AN602 was never a weapon, it was a single product, the design of which allowed reaching a power of 100 Mt TE. The test of a 50-megaton bomb was, among other things, a test of the performance of the product design for 100 megatons.[63] This bomb was intended exclusively for psychological pressure on the Americans.[19]

Experts began to develop military missiles for warheads (150 Mt and more) that have been redirected for space use:

• UR-500 – (warhead mass – 40 tons, virtually implemented as a carrier rocket – "Proton" – GRAU index – 8K82)
• N-1 – (warhead mass – 75–95 tons, the development was reoriented into a carrier for the lunar program, the project was brought to the stage of flight design tests and closed in 1976, GRAU index – 11A52)
• R-56 – (GRAU index – 8K67)[64]

There existed a common (but entirely false) myth that the Tsar Bomba was designed per personal order from Nikita Khrushchev at a meeting on July 10, 1961 with a total research and development time of only 112 days; the actual development of the final stage of the Tsar Bomba (then already placed in KB-11, now the All-Russian Scientific Research Institute of Experimental Physics) did indeed take 112 days.[35] In fact, development began in 1956.[25]

• Footage from a Soviet documentary about the bomb is featured in Trinity and Beyond: The Atomic Bomb Movie (Visual Concept Entertainment, 1995), where it is referred to as the Russian monster bomb.[65] The video states that the Tsar Bomba project broke the voluntary moratorium on nuclear tests. In fact, Soviets restarted their tests and broke the unilateral voluntary moratorium 30 days before Tsar Bomba, testing 45 times in that month. Since the moratorium was unilateral there was no multilateral legal obstacle. The US had declared their own one-year unilateral moratorium on nuclear tests and as that year had expired, the US had already announced that it considered itself free to resume testing without further notice. Later it was stated that the US had not resumed testing at the time of the Tsar Bomba test.[66] That announcement was in error, as the US had in fact tested five times under Operation Nougat between the USSR's ending of the moratorium on 1 October and the Tsar Bomba test on 30 October.
• "World's Biggest Bomb", a 2011 episode of the PBS documentary series Secrets of the Dead produced by Blink Films & WNET, chronicles the events leading to the detonations of Castle Bravo and the Tsar Bomba.
• In connection with the celebration of 75 years of nuclear industry, Rosatom released a declassified documentary video of the Tsar Bomba test on YouTube in August 2020.[67] It is currently viewable on YouTube.

Wikimedia Commons has media related to Tsar Bomba.

• Father of All Bombs
• GBU-43/B MOAB
• Soviet atomic bomb project
• Status-6 Oceanic Multipurpose System
• Cold War

• Sublette, Carey, ed. (30 October 2018). "Tsar Bomba". NuclearWeaponArchive.org.
• Video of the Tsar Bomba delivery, blast and cloud (video)."Sonicbomb.com".
• Tsar Bomb – Official video material from the Soviet army with English subtitles on YouTube