View source for Tsar Bomba

{{Short description|Most powerful nuclear weapon ever tested}}
{{Redirect|Largest bomb|the list of most powerful nuclear weapons|List of most powerful nuclear weapons}}
{{Other uses}}
{{Use dmy dates|date=October 2017}}
{{Infobox weapon
| name               = Tsar Bomba
| image              = Tsar bomba=eM.png
| caption            = Ground-level view of detonation (source: ''[https://raosproject.fi/ru/ Rosatom State Corporation Communications Department]'': [[Rosatom]]: 20–08–2020 [https://atom75.com/#history_34 public release])<ref>{{cite web
| url =https://www.businessinsider.com/russia-declassified-footage-of-largest-nuclear-blast-tsar-bomba-2020-9?r=US&IR=T 
|author=Bendix, Aria
|date=September 1, 2020
| title =A cloud of smoke and dust rises in the sky after the Tsar Bomba was detonated in October 1961 
| work =[[Ministry of Medium Machine Building]] (30-10-1961), Rosatom (20-08-2020), [[YouTube]] www.youtube.com/watch?v=XJhZ3i-HXS0 (24-08-2020), www.businessinsider.com [[Business Insider]] (September 1, 2020)
| access-date =9 June 2021 }}</ref>
| type               = [[Thermonuclear weapon|Thermonuclear]] <!-- Type selection -->
| designer           = {{ubl|[[Yulii Khariton]]|[[Andrei Sakharov]]|[[Viktor Adamsky]]|[[Yuri Babayev]]|{{ill|Yuri Smirnov (physicist)|lt=Yuri Smirnov|ru|Смирнов, Юрий Николаевич (физик)}}|[[Yuri Trutnev (scientist)|Yuri Trutnev]]|[[Yakov Zeldovich]]}}
| number             = 1 operational (2 "prototypes")
| length             = {{cvt|8|m}}<ref name=atomicheritage/>
| diameter           = {{cvt|2.1|m}}<ref name=atomicheritage/>
| origin             = [[Soviet Union]]
| is_explosive       = yes
| weight             = {{cvt|27000|kg}}<ref name=atomicheritage/>
| detonation         = [[Barometric sensor]]<ref>{{cite web
 |url          = https://www.atomicheritage.org/history/tsar-bomba
 |title        = The Test
 |date         = August 8, 2014
 |work         = [[Atomic Heritage Foundation|atomicheritage.org]] & [[National Museum of Nuclear Science & History|US National Museum of Nuclear Science & History]]
 |archive-url  = https://web.archive.org/web/20210705174149/https://www.atomicheritage.org/history/tsar-bomba
 |archive-date = 5 July 2021
 |access-date  = 8 June 2021
 |url-status   = live
}}</ref>
| yield              = {{convert|50-58|MtonTNT|lk=on}}<ref name="TsarSize"/>
}}

The '''Tsar Bomba''' ([[code name]]: ''Ivan''<ref>{{cite web |url=http://www.aif.ru/society/history/1371856 |title=Смотрины "Кузькиной матери". Как СССР сделал и взорвал "Царь-бомбу" |date=2014-10-29}}, Russian</ref> or ''Vanya'', internal designation "'''AN602'''") was the most powerful [[nuclear weapon]] or weapon of any kind ever constructed and tested.<ref>{{Cite web |last=Lengel |first=Edward G. |author-link=Edward G. Lengel |date=2020-08-29 |title=Tsar Bomba: The Largest Atomic Test in World History |url=https://www.nationalww2museum.org/war/articles/tsar-bomba-largest-atomic-test-world-history |access-date=2024-05-08 |website=The National WWII Museum {{!}} New Orleans |language=en}}</ref><ref>{{Cite book |last=Dabrowski |first=Krzysztof |title=Tsar Bomba: Live Testing of Soviet Nuclear Bombs, 1949-1962 |publisher=Helion & Company |year=2021 |isbn=978-1-915113-37-5 |pages=v, 28, 49 |language=en}}</ref> A project of the [[Soviet Union]], it was a [[Thermonuclear weapon|thermonuclear]] [[aerial bomb]], tested on 30 October 1961 at the [[Novaya Zemlya#Nuclear testing|Novaya Zemlya site]] in the country's far north. The bomb yielded 50 [[megatons of TNT]].

The Soviet physicist [[Andrei Sakharov]] oversaw the project at [[Arzamas-16]], while the main work of design was by Sakharov, [[Viktor Adamsky]], [[Yuri Babayev]], {{ill|Yuri Smirnov (physicist)|lt=Yuri Smirnov|ru|Смирнов, Юрий Николаевич (физик)}}, and [[Yuri Trutnev (scientist)|Yuri Trutnev]]. The project was ordered by [[General Secretary of the Communist Party|First Secretary of the Communist Party]] [[Nikita Khrushchev]] in July 1961 as part of the Soviet resumption of [[nuclear testing]] after the [[Partial Nuclear Test Ban Treaty#Khrushchev and a moratorium: 1958–1961|Test Ban Moratorium]], with the detonation timed to coincide with the [[22nd Congress of the Communist Party of the Soviet Union]] (CPSU).<ref name="wellerstein2">{{cite journal |last=Wellerstein |first=Alex |year=2021 |title=The untold story of the world's biggest nuclear bomb |url=https://thebulletin.org/2021/11/the-untold-story-of-the-worlds-biggest-nuclear-bomb/ |journal=The Bulletin of the Atomic Scientists}}</ref>

Tested on 30&nbsp;October 1961, the test verified new design principles for high-yield thermonuclear charges, allowing [[Nuclear explosive|nuclear explosives]] "of practically unlimited power".<ref>{{cite journal |last1=Adamsky |first1=V.B. |last2=Smirnov |first2=Yu.N. |title=50-мегатонный взрыв над Новой Землей [50 megaton explosion over Novaya Zemlya"] |journal=Вопросы истории естествознания и техники |year=1995}}</ref> The bomb was dropped by parachute from a [[Tupolev Tu-95|Tu-95V]] aircraft, and detonated autonomously {{convert|4000|m|ft}} above the cape [[Sukhoy Nos]] of [[Severny Island]], [[Novaya Zemlya]], {{convert|15|km|nmi|frac=2|abbr=off}} from [[Mityushikha Bay]], north of [[Matochkin Strait]].<ref name="Sakharov memoirs">{{cite book |title=Memoirs |url=https://archive.org/details/memoirs00sakh |url-access=registration |last=Sakharov |first=Andrei |publisher=[[Alfred A. Knopf]] |year=1990 |isbn=978-0-679-73595-3 |location=New York |pages=[https://archive.org/details/memoirs00sakh/page/215 215]–225 |author-link=Andrei Sakharov}}</ref><ref>{{cite journal |last1=Khalturin|first1=Vitaly I. |last2=Rautian|first2=Tatyana G. |last3=Richards|first3=Paul G. |last4=Leith|first4=William S. |year=2005 |title=A Review of Nuclear Testing by the Soviet Union at Novaya Zemlya, 1955–1990 |url=http://www.princeton.edu/~globsec/publications/pdf/13_1-2khalturin%20NZ%201-42%20.pdf |url-status=dead |journal=Science and Global Security |volume=13 |issue=1 |pages=1–42 |doi=10.1080/08929880590961862 |bibcode=2005S&GS...13....1K |s2cid=122069080 |archive-url=https://web.archive.org/web/20060614080624/http://www.princeton.edu/~globsec/publications/pdf/13_1-2khalturin%20NZ%201-42%20.pdf |archive-date=14 June 2006 |access-date=14 October 2006 |df=dmy-all}}</ref><ref name="CIA" /> Blast data and footage was recorded by a Soviet [[Tu-16]]. Both aircraft received radiation flash damage.

The [[bhangmeter]] results and other data suggested the bomb yielded around {{cvt|58|MtonTNT|0|abbr=off}},<ref>{{Cite web|url=http://nuclearweaponarchive.org/Russia/TsarBomba.html|title=The Soviet Weapons Program - The Tsar Bomba|website=nuclearweaponarchive.org}}</ref> which was the accepted yield in technical literature until 1991, when Soviet scientists revealed that their instruments indicated a yield of {{cvt|50|MtonTNT|0}}.<ref name="TsarSize" /> As they had the instrumental data and access to the test site, their yield figure has been accepted as more accurate.<ref name="TsarSize" /><ref name="Johnson">{{cite web |series=Multimegaton Weapons |title=The Largest Nuclear Weapons |first=William Robert |last=Johnson |date=2 Apr 2009 |url=http://www.johnstonsarchive.net/nuclear/multimeg.html#S2}}</ref> In theory, the bomb would have had a yield over {{cvt|100|MtonTNT|0}} if it had included the [[natural uranium]]<ref name="Veselov, A.V. 2006 7" /> [[Tamper (nuclear weapon)|tamper]] which featured in the design but was [[Nuclear weapon design#Designs with lead tampers|replaced with lead]] in the test to reduce radioactive fallout.<ref name="Veselov, A.V. 2006 7" /> As only one bomb was built to completion, that capability has never been demonstrated.<ref name="Veselov, A.V. 2006 7">{{cite book|author=Veselov, A.V.|title=Tsar Bomba |publisher=Atompress |date=2006 |page=7}}</ref> The design was too large and heavy to be deployed operationally, although it influenced the initial development of the [[Proton rocket]]. The next four [[List of nuclear weapons tests#Most powerful tests|most powerful tests]] ever took place were carried out by the Soviet Union the following year.

The United States government's reaction emphasized the lack of military usefulness, and signalled readiness to sign the [[Partial Nuclear Test Ban Treaty]], eventually realized in 1963. It also prompted the disclosure of the US [[B41 nuclear bomb]]'s {{cvt|25|MtonTNT|0}} yield. In the Western world, the reaction focused on the incorrectly assumed record level of [[fission product]] fallout from a typical fissionable tamper design, similar to the US [[Castle Bravo]] test disaster.<ref name="g380">{{cite web |date=1961-10-31 |title=TEST DENOUNCED; White House Asserts Purpose Is to Incite 'Fright and Panic' Soviet Explodes Biggest A-Bomb, but 50-Megaton Force Is Doubted by U.S. Aides TEST DENOUNCED BY WHITE HOUSE 'Fright and Panic' Held Aim--Fall-out on Russia Is Hinted by Low Altitude |url=https://www.nytimes.com/1961/10/31/archives/test-denounced-white-house-asserts-purpose-is-to-incite-fright-and.html?searchResultPosition=56 |access-date=2025-07-11 |website=The New York Times}}</ref><ref name="t629">{{cite web |date=1961-10-22 |title=Sweden Rushes Precautions |url=https://www.nytimes.com/1961/10/22/archives/sweden-rushes-precautions.html?searchResultPosition=43 |access-date=2025-07-11 |website=The New York Times}}</ref><ref name="d127">{{cite web |date=2022-11-15 |title=UK: RUSSIA'S 50 MEGATON BOMB: PROFESSOR P. RITCHIE CALDER'S VIEWS. |url=https://www.britishpathe.com/asset/118331/ |access-date=2025-07-11 |website=British Pathé}}</ref> In fact, the Tsar Bomba derived only 3% of its yield from fission, or 1.5 Mt.<ref name="bulletin" />

== Name ==
The name '''Tsar Bomba''' is a recent invention dating to the 1990s. Contemporarily, the bomb was referred to by [[Western Bloc]] press as the "50-megaton bomb" or "100-megaton bomb".<ref name="j772">{{cite web |last=Gaulkin |first=Thomas |date=2021-11-14 |title=The untold story of the world’s biggest nuclear bomb |url=https://thebulletin.org/2021/11/the-untold-story-of-the-worlds-biggest-nuclear-bomb/ |access-date=2025-11-09 |website=Bulletin of the Atomic Scientists}}</ref>

Tsar Bomba was a modification of an earlier project, '''RN202''', which used a ballistic case of the same size but a very different internal mechanism.<ref name="Veselov, A.V. 2006 7" /> Many published books, even some authored by those involved in product development of 602, contain inaccuracies that are replicated elsewhere,<ref name="Chernyshev" /> including wrongly identifying Tsar Bomba as '''RDS-202''' or '''RN202'''.

== Background ==
In the late 1950s [[Cold War]], the US nuclear weapons arsenal greatly exceeded that of the USSR in quantity of weapons, total explosive yield of weapons, and their ability to deliver the weapon. In the early part of the decade, the [[Strategic Air Command]] had begun deploying nuclear-capable bombers, as well as actual weapons, to airbases hosted by US allies within striking distance of the Soviet Union, as well as deploying them on aircraft carriers and on [[medium-range ballistic missile]]s in the United Kingdom. The USSR had a credible ability to threaten American allies in Western Europe and Asia via a limited bomber and short-range missile force, had tested [[RDS-37|a multi-stage thermonuclear weapon]] in 1955, and had begun testing a [[R-7 Semyorka|prototype rocket]] for an [[intercontinental ballistic missile]] in 1957. Its leadership was well aware that the USSR's deployed nuclear forces in 1960 could not reliably and credibly threaten targets in the continental United States, and that in the event of war, the Soviet Union would struggle to reply in kind.<ref name=Chernyshev/> This in turn threatened to weaken Soviet leverage in hot-spots like Berlin, which had been the subject of Soviet and American tension since the end of [[World War II]].

Given the Soviet Union's strategic disadvantage concerning America's nuclear weapons possessions, foreign policy and [[propaganda]] considerations during the leaderships of [[Georgy Malenkov]] and [[Nikita Khrushchev]] made a response to the perceived US [[nuclear blackmail]] imperative for both international and domestic reasons. The creation of the Tsar Bomba represented part of a larger effort to maintain the [[Nuclear strategy|concept of nuclear deterrence]], and to impress (and terrify) both domestic and international audiences with the strength of the Soviet nuclear weapons program, even though the weapon itself was arguably impractical.<ref>{{cite book |last1=Зубок |first1=Владислав Мартинович |year=2011 |chapter=«Ядерная доктрина» Хрущева |editor1-last=Пер. М. Макбал |title=Неудавшаяся империя Советский Союз в холодной войне от Сталина до Горбачева|series=История сталинизма |publisher=Российская политическая энциклопедия |pages=/672 |ref=Зубок}}</ref>

== Name ==
The bomb was officially known as "product 602" ({{lang|ru|изделие 602}}) or "AN602", and codenamed "Ivan".<ref name="Бомбы с ласковыми именами">{{cite web|url=https://nvo.ng.ru/armament/2005-06-10/1_bombs.html |title=Бомбы с ласковыми именами |access-date=10 December 2020}}</ref> The usage of different names can be a source of confusion. The Tsar Bomba, being a modification of (the) [[#Product 202|RN202]], is sometimes mistakenly labelled as RDS-37, RDS-202 or PH202 (product 202).<ref name="Veselov, A.V. 2006 7"/>

Unofficially, the bomb would later become known as "Tsar Bomba" and "[[Kuzma's mother|Kuzka's mother]]" ({{lang|ru|Кузькина мать}}, {{transliteration|ru|Kuz'kina mat'}}). The name Tsar Bomba (loosely translated as ''Emperor of Bombs'') comes from an allusion to two other Russian historical artifacts, the [[Tsar Cannon]] and the [[Tsar Bell]], both of which were created as showpieces but whose large size made them impractical for use. The name "Tsar Bomba" does not seem to have been used for the weapon prior to the 1990s.<ref name="wellerstein2"/> The name "Kuzka's Mother" was inspired by the statement of Khrushchev to then US Vice President [[Richard Nixon]]: "We have funds at our disposal that will have dire consequences for you. We will show you Kuzka's mother!"<ref>{{cite news|url=https://ria.ru/20150818/1192808216.html |title=Росатом покажет "Кузькину мать" на выставке в Москве |newspaper=Риа Новости |date=18 August 2015 |access-date= 10 December 2020}}</ref><ref>{{cite book |title=Memoirs of Nikita Khrushchev |volume=3: Statesman (1953–1964) |author=Nikita Khrushchev |author-link=Nikita Khrushchev |publisher=The Pennsylvania State University Press |editor=Sergei Khrushchev |editor-link=Sergei Khrushchev |location=University Park, PA |page=292}}</ref>

The [[Central Intelligence Agency]] (CIA) designated the test as "JOE 111" using their "JOE" counting scheme, which had begun with [[RDS-1]] in 1949.<ref name="CIA">{{cite report |publisher=Central Intelligence Agency |series=[[National Intelligence Estimate]] |volume=11-2A-62 |url=http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0000843187.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://www.foia.cia.gov/sites/default/files/document_conversions/89801/DOC_0000843187.pdf |archive-date=2022-10-09 |url-status=live |title=Soviet Atomic Energy Program |date=16 May 1962 |pages=2, 13}}</ref>

== Development ==
[[File:Tsar Bomba Revised.jpg|thumb|right|A Tsar Bomba-type casing on display at the Sarov atomic bomb museum, [[Sarov]]]]
The development of a very large bomb began in 1956<ref name="rc.nsu.ru">{{cite web |url=https://rc.nsu.ru/text/metodics/adamsky.html |title=50-мегатонный взрыв над Новой Землей |access-date=10 December 2020 |archive-date=23 March 2016 |archive-url=https://web.archive.org/web/20160323012353/https://rc.nsu.ru/text/metodics/adamsky.html |url-status=dead }}</ref> 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 [[All-Russian Scientific Research Institute Of Technical Physics|NII-1011]]. The modern name of NII-1011 is the "Russian Federal Nuclear Center or the 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 [[Ministry of Medium Machine Building]] was signed on 5 April 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 [[All-Russian Scientific Research Institute of Experimental Physics|KB-11]] (VNIIEF), V.&nbsp;B.&nbsp;Adamsky was developing,<ref name="rc.nsu.ru"/> and the physical scheme was developed by [[Andrei Sakharov]], Yu.&nbsp;N.&nbsp;Babaev, Yu.&nbsp;N.&nbsp;Smirnov, and Yu.&nbsp;A.&nbsp;Trutnev.<ref name=Chernyshev/>

=== Product 202 ===
After the successful test of the [[RDS-37]], KB-11 employees (Sakharov, [[Yakov Zeldovich|Zeldovich]], and Dovidenko) performed a preliminary calculation and, on 2 February 1956, they handed over to N.&nbsp;I.&nbsp;Pavlov, a note with the parameters for charges of {{cvt|150|MtonTNT|0}} and the possibility of increasing the power to {{cvt|1|GtonTNT|lk=on|1}}.<ref name=Chernyshev/><ref>{{cite web|url=http://elib.biblioatom.ru/text/atomny-proekt-sssr_t3_kn2_2009/go,440/ |title=Атомный проект СССР Т. 3 Кн. 2, 2009, №192. Записка А. Д. Сахарова, Я. Б. Зельдовича и В. А. Давиденко Н. И. Павлову с оценкой параметров изделий мощностью в 150 мегатонн и один миллиард тонн ТНТ |pages=440–441 |access-date= 10 December 2020 |ref={{sfnref|Атомный проект|2009}} }}</ref>

After the creation in 1955 of the second nuclear center – NII-1011, in 1956, by a resolution of the Council of Ministers, the center was assigned the task of developing an ultra-high-power charge, which was called "Project 202".<ref name=Chernyshev/>

On 12 March 1956, a draft Joint Resolution of the [[Central Committee of the Communist Party of the Soviet Union]] (CPSU Central Committee) and the Council of Ministers of the Soviet Union on the preparation and testing of the 202 product was adopted. The project planned to develop a version of the RDS-37 with a capacity of {{cvt|30|MtonTNT|0}}.<ref>Президиум ЦК КПСС. 1954–1964. Черновые протокольные записи заседаний. Стенограммы. Постановления. / Гл. ред. А. А. Фурсенко. – М. : Российская политическая энциклопедия (РОССПЭН), 2006. – Т. 2. : Постановления. 1954–1958. – 1120 с.:
Принять проект постановления ЦК КПСС и Совета Министров СССР о подготовке и проведении испытания изделия 202.
<br />
Включить в проект постановления пункты, обязывающие:
<br />
а) Министерство среднего машиностроения (т. Завенягина) и Министерство обороны СССР (т. Жукова) по окончании подготовительных работ к проведению испытания изделия 202 доложить ЦК КПСС о положении дел;
<br />
б) Министерство среднего машиностроения (т. Завенягина) проработать вопрос о введении в конструкцию изделия 202 специальной ступени предохранения, обеспечивающей несрабатывание изделия при отказе парашютной системы, и свои предложения доложить ЦК КПСС.
<br />
Поручить тт. Ванникову и Курчатову окончательную редакцию текста данного постановления.
</ref>
RDS-202 was designed with a maximum calculated power release of {{cvt|50|MtonTNT|0}}, with a diameter of {{cvt|2.1|m}}, a length of {{cvt|8|m}}, weighing {{convert|26|t|ST}} with a parachute system and structurally coordinated with the [[Tupolev Tu-95|Tu-95]]-202 carrier aircraft specially converted for its use.<ref>{{cite web |url=http://elib.biblioatom.ru/text/kiryushkin_kuzkina-mat_2015/go,9/ |access-date=29 November 2021 |first=V. D. |last=Kiryushkin |title=Кузькиной матери}}</ref> On 6 June 1956, the NII-1011 report described the RDS-202 thermonuclear device with a design power of up to {{cvt|38|MtonTNT|0}} with the required task of {{cvt|20–30|MtonTNT|0}}.{{sfn|Атомный проект|2009|pp=480–482 |loc=№208. [http://elib.biblioatom.ru/text/atomny-proekt-sssr_t3_kn2_2009/go,480/ Отчет НИИ-1011 по обоснованию конструкции и расчетам изделия РДС-202]}} In reality, this device was developed with an estimated power of {{cvt|15|MtonTNT|0}},{{sfn|Атомный проект|2009|pp=492–493 |loc=№215. [http://elib.biblioatom.ru/text/atomny-proekt-sssr_t3_kn2_2009/go,492/ Записка А. П. Завенягина, Б. Л. Ванникова и П. М. Зернова в ЦК КПСС с представлением проекта постановления Президиума ЦК КПСС о переносе срока испытания изделия «202»]}} after testing the products "40GN", "245" and "205" its tests were deemed inappropriate and canceled.<ref name=Chernyshev/>

The Tsar Bomba differs from its parent design – the RN202 – in several places. The Tsar Bomba was a [[Nuclear weapon design#Fission-fusion-fission bombs vs. three-stage (tertiary) bombs|three-stage bomb]] with a Trutnev-Babaev<ref>{{cite web |url=https://www.energyglobalnews.com/tsar-bomba-the-most-powerful-human-made-explosive-ever-detonated/ |title=Tsar Bomba – The Most Powerful Human-made Explosive Ever Detonated|date=26 September 2020 |publisher=energy global news: the quest for energy |access-date=5 December 2020}}</ref> second- and third-stage design,<ref>{{cite book |last1=Андрюшин |first1=И.А. |last2=Чернышев |first2=А.К. |last3=Юдин |first3=Ю.А. |title=Укрощение ядра. Страницы истории ядерного оружия и ядерной инфраструктуры СССР |date=2003 |publisher=Типография «Красный Октябрь» |location=Саров, Саранск |isbn=978-5-7493-0621-7 |pages=481 |url=http://www.atomic-energy.ru/files/books/Ukroschenie%20yadra%20(2005).pdf |access-date=19 April 2015}}</ref> with a [[nuclear weapon yield|yield]] of 50 Mt.<ref name="TsarSize">The yield of the test has been estimated at {{cvt|50|to|58|MtonTNT|lk=on}} by different sources over time. Today all Russian sources use 50 Mt as the official figure. See the section "Was it 50&nbsp;Megatons or 57?" at {{cite web |url=http://www.nuclearweaponarchive.org/Russia/TsarBomba.html |title=The Tsar Bomba ("King of Bombs") |access-date=30 October 2014}}</ref> This is equivalent to about 1,570&nbsp;times the combined energy of the bombs that [[Atomic bombings of Hiroshima and Nagasaki|destroyed Hiroshima and Nagasaki]],<ref>{{cite book |last=DeGroot |first=Gerard J. |title=The Bomb: A Life |place=Cambridge, Massachusetts |publisher=[[Harvard University Press]] |year=2005 |page=254}}</ref> 10&nbsp;times the combined energy of all the conventional explosives used in [[World War II]],<ref name=pbs>{{cite web |title=The World's Biggest Bomb |publisher=[[PBS]] [[Secrets of the Dead]] |date=17 May 2011 |url=https://www.pbs.org/wnet/secrets/the-worlds-biggest-bomb-about-this-episode/846/ |access-date=29 July 2016}}</ref> one quarter of the estimated yield of the [[1883 eruption of Krakatoa]], and 10% of the combined yield of all other nuclear tests to date. A three-stage hydrogen bomb uses a [[fission bomb]] primary to compress a thermonuclear secondary, as in most hydrogen bombs, and then uses energy from the resulting explosion to compress a much larger additional thermonuclear stage. There is evidence that the Tsar Bomba had several third stages rather than a single very large one.<ref name="Nuclearweaponarchive.com">{{cite web |url=http://www.nuclearweaponarchive.org/Russia/TsarBomba.html |title=Tsar Bomba |publisher=Nuclear Weapon Archive |access-date=3 November 2007}}</ref> RDS-202 was assembled on the principle of radiation implosion, which was previously tested during the creation of RDS-37. Since it used a much heavier secondary module than in the RDS-37, two primary modules (charges), located on opposite sides of the secondary module, were used to compress it.<ref>{{cite web |url=http://elib.biblioatom.ru/text/dela-i-gody_2010/go,18/ |access-date=29 November 2021 |title=50-летию КБ-2 РФЯЦ—ВНИИТФ посвящается |last1=Дела |last2=Годы}}</ref><ref>{{cite web |url=http://book.sarov.ru/wp-content/uploads/2018/07/Atom-73-2017-2.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://book.sarov.ru/wp-content/uploads/2018/07/Atom-73-2017-2.pdf |archive-date=2022-10-09 |url-status=live |access-date=29 November 2021 |title=Его именем назван уральский ядерный центр |last=Болошин |first=Н. П.}}</ref> This physical charging scheme was later used in the design of the AN-602, but the AN-602 thermonuclear charge itself (secondary module) was new. The RDS-202 thermonuclear charge was manufactured in 1956, and was planned for testing in 1957, but was not tested and put into storage. Two years after the manufacture of the RDS-202, in July 1958, it was decided to remove it from storage, dismantle and use automation units and charge parts for experimental work.<ref>Order No. 277 of the Ministry of Medium Machine Building dated 23 May 1957</ref> The CPSU Central Committee and the Council of Ministers of the USSR adopted a draft Joint Resolution on 12 March 1956, on the preparation and testing of ''izdeliye&nbsp;202'', which read:

{{blockquote|Adopt a draft resolution of the CPSU Central Committee and the USSR Council of Ministers on the preparation and testing of ''izdeliye&nbsp;202''.
Paragraphs required for inclusion in the draft resolution:

(a) The Ministry of Medium Engineering (Comrade [[Avraami Zavenyagin]]) and the Ministry of Defense of the USSR (Comrade [[Georgy Zhukov]]) at the end of the preparatory work for the test of ''izdeliye&nbsp;202'' to report to the CPSU Central Committee on the situation;

(b) The Ministry of Medium Engineering (Comrade Zavenyagin) to solve the issue of introducing a special stage of protection into the design of ''izdeliye&nbsp;202'' to ensure disarming of the product in the event of a failure of the parachute system, as well as their proposals reported to the CPSU Central Committee.

Comrades [[Boris Vannikov]] and Kurchatov are assigned to edit the final version of this resolution.}}

=== Product 602 ===
[[File:Tsar Bomba possible primary.jpg|thumb|View of the possible fission bomb primary within the Tsar Bomba casing, under construction at [[All-Russian Scientific Research Institute of Experimental Physics|KB-11]].]]
In 1960, KB-11 began developing a thermonuclear device with a design capacity of {{convert|100|MtonTNT|spell=in|abbr=off|0}}. In February 1961, the leaders of KB-11 sent a letter to the Central Committee of the CPSU with the subject line "Some questions of the development of nuclear weapons and methods of their use", which, among other things, raised the question of the expediency of developing such a 100&nbsp;Mt device. On 10 July 1961, a discussion took place in the Central Committee of the CPSU, at which First Secretary Nikita Khrushchev supported the development and testing of this super-powerful bomb.<ref name=Chernyshev/>

To speed up the work on Tsar Bomba, it was based on the 202 Project, but was a new project, developed by a different group. For KB-11, six casings for the Project 202 bomb already manufactured at [[NII-1011]] and a set of equipment developed for the 202 Project testing were used.<ref name=Chernyshev/>

Tsar Bomba had a "three-stage" design: the first stage is the necessary fission trigger. The second stage was two{{Citation needed|date=March 2025}} relatively small thermonuclear charges with a calculated contribution to the explosion of {{cvt|1.5|MtonTNT|0}}, which were used for radiation implosion of the third stage, the main thermonuclear module located between them, and starting a thermonuclear reaction in it, contributing 50 Mt of explosion energy. As a result of the thermonuclear reaction, huge numbers of high-energy fast neutrons were formed in the main thermonuclear module, which, in turn, initiated the fast fission nuclear reaction in the nuclei of the surrounding [[uranium-238]], which would have added another 50 Mt of energy to the explosion, so that the estimated energy release of Tsar Bomba was around 100 Mt.<ref name="nweapon.ru">{{cite web|url=http://www.nweapon.ru/tests/rus/50mt_yield/index.htm |title=Антон Волков. Испытание заряда 50 Мт – "Кузькина мать" |archive-url=https://web.archive.org/web/20091022221200/http://www.nweapon.ru/tests/rus/50mt_yield/index.htm |access-date=10 December 2020|archive-date=22 October 2009 }}</ref>

The test of such a complete three-stage 100 Mt bomb was rejected due to the extremely high level of radioactive contamination that would be caused by the fission reaction of large quantities of uranium-238.<ref>{{cite book|last=Sakharov|first=Andrei|author-link=Andrei Sakharov |title=Memoirs |publisher=Alfred A. Knopf |year=1990 |location=New York |pages=215–225 |language=en |isbn=0-679-73595-X}}</ref> During the test, the bomb was used in a two-stage version. A.&nbsp;D.&nbsp;Sakharov suggested using the non-fissionable lead instead of the uranium-238 in the secondary's [[Tamper (nuclear weapon)|tamper]], which reduced the bomb's energy to 50 Mt, and, in addition to reducing the amount of radioactive fission products, avoided the fireball's contact with the Earth's surface, thus eliminating radioactive contamination of the soil and the distribution of large amounts of fallout into the atmosphere.<ref name=Chernyshev/> In the United States nuclear complex this use of lead tampers became common after the [[Castle Bravo]] testing disaster, and was known as the "materials substitution method".

Many technical innovations were applied in the design of Tsar Bomba. The thermonuclear charge was made according to the "bifilar" scheme – the radiation implosion of the main thermonuclear stage was carried out from two opposite sides. These secondary charges produced [[Radiation implosion|X-ray compression]] of the main thermonuclear charge. For this, the second stage was separated into two fusion charges which were placed in the front and rear parts of the bomb, for which a synchronous detonation was required with a difference in initiation of no more than 100 nanoseconds.<!-- Does this imply two fission primaries as well? It would seem to, as nothing else could guarantee such synchronization of two separate secondaries. --> To ensure synchronous detonation of charges with the required accuracy, the sequencing unit of the detonation electronics was modified at [[NL Dukhov All-Russian Research Institute of Automation|KB-25]] (now "Federal State Unitary Enterprise "NL Dukhov All-Russian Scientific Research Institute of Automation")(VNIIA).<ref>{{cite web|url=http://www.proatom.ru/modules.php?name=News&file=article&sid=3364 |title=ЦАРЬ-БОМБЕ 50 ЛЕТ |access-date=10 December 2020}}</ref>

== Development of the carrier aircraft ==

The initial three-stage design of Tsar Bomba was capable of yielding approximately 100 Mt (approximately 3,000&nbsp;times the power of the Hiroshima (15 kt) and Nagasaki (21 kt) bombs, combined);<ref name=":0">{{Cite web |url=http://www.bbc.com/future/story/20170816-the-monster-atomic-bomb-that-was-too-big-to-use |title=The monster atomic bomb that was too big to use |last=Dowling |first=Stephen |date=16 August 2017 |access-date=2017-11-10 |df=dmy-all}}</ref> 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, uranium-238 in the [[Tamper (nuclear weapon)|tamper]] was replaced with [[lead]]. This eliminated [[fast fission]] reactions from the tamper 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, as most of the radioactive intensity of nuclear fallout is caused by the creation of [[fission products]].<ref name=bulletin>{{cite journal |title=The Khariton Version |journal=[[Bulletin of the Atomic Scientists]] |last1=Khariton |first1=Yuli |last2=Smirnov |first2=Yuri |url=http://www.thebulletin.org/issues/1993/may93/may93Khariton.html |date=May 1993 |volume=49 |issue=4 |pages=20–31 |doi=10.1080/00963402.1993.11456341 |bibcode=1993BuAtS..49d..20K |archive-url=https://web.archive.org/web/20030221213340/http://www.thebulletin.org/issues/1993/may93/may93Khariton.html |archive-date=21 February 2003|url-access=subscription }}</ref> There was a strong incentive for this modification, since most of the fallout from a test of the bomb would probably have descended on populated Soviet territory.<ref name="Nuclearweaponarchive.com" /><ref name="Adamsky and Smirnov">{{cite journal|last=Adamsky|first=Viktor|author2=Yuri Smirnov |title=Moscow's Biggest Bomb: the 50 Megaton Test of October 1961 |url=http://large.stanford.edu/courses/2018/ph241/castandea1/docs/cwihp-bull-4.pdf#page=3 |archive-url=https://ghostarchive.org/archive/20221009/http://large.stanford.edu/courses/2018/ph241/castandea1/docs/cwihp-bull-4.pdf#page=3 |archive-date=2022-10-09 |url-status=live |journal=Cold War International History Project Bulletin |issue=4 |pages=3, 19–21 |date=Fall 1994}}</ref>

The first studies on "Topic&nbsp;242" began immediately after [[Igor Kurchatov]] talked with [[Andrei Tupolev]] in late 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 extensively 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% of 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&nbsp;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.&nbsp;M.&nbsp;Kulikov until 1959, and passed without major issues.

Despite the creation of the Tu-95V bomb-carrier aircraft, the 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 [[Uzyn (air base)|Uzyn]], 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 [[anti-flash white|special, reflective white paint]].

In late 1961, the aircraft was modified for testing Tsar Bomba at the Kuibyshev aircraft plant.<ref name=Chernyshev/>

== Test ==

{{Infobox Military Test Site
| name          = Novaya Zemlya
| image         = Ivan bomb.png
| caption       = Novaya Zemlya was the site of the world's largest nuclear explosion, the 50 Mt Tsar Bomba
| mapframe = yes
| mapframe-zoom = 3
| mapframe-marker = viewpoint
| image_mapsize = 
| coordinates ={{Coord|73|48|26|N|54|58|54|E| display=inline}}
| map_caption   = Site of the detonation on [[Novaya Zemlya]]
| type          = [[Nuclear testing|Nuclear test]] site
| site_area     = land: {{convert|55200|km2|sqmi|abbr=on}} <br />water: {{convert|36000|km2|sqmi|abbr=on}}
| operator      = [[Russia|Russian Federation]] (formerly [[Soviet Union]])
| status        = Active
| dates         = 1955–present
| nuclear_tests = 224
| subcritical_tests = not known
}}

[[Nikita Khrushchev]], the [[First Secretary of the Communist Party of the Soviet Union|first secretary of the Communist Party]], announced the upcoming tests of a 50-Mt bomb in his opening report at the [[22nd Congress of the Communist Party of the Soviet Union]] on 17 October 1961.<ref name=Bogolov/> Before the official announcement, in a casual conversation, he told an American politician about the bomb, and this information was published on 8 September 1961, in ''[[The New York Times]]''.<ref name="Adamsky and Smirnov"/> The Tsar Bomba was tested on 30 October 1961.

The [[Tupolev Tu-95]]V aircraft No. 5800302 carrying the bomb took off from the [[Olenya (air base)|Olenya airfield]],<ref>{{Cite web |title=1961_1130 Испытания водородной бомбы. Полный фильм - YouTube |url=https://www.youtube.com/watch?v=GYG4p-ybN-M | time=8:58 | access-date=June 6, 2025 |website=[[YouTube]] | date=25 February 2022 }}</ref> and flew to State Test Site No. 6 of the USSR Ministry of Defense on [[Novaya Zemlya#Nuclear testing|Novaya Zemlya]]<ref name=Bogolov>Боголепов и Гостев, 08:57</ref> with a crew of nine:<ref name=Chernyshev>{{cite book| author=Chernyshev, A. K. |title=Record Soviet explosion: on the way to nuclear deterrence|publisher= VNIIEF |date= 2011}}</ref>

* Test pilot – Major [[Andrei Durnovtsev|Andrei Yegorovich 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 [[Tupolev Tu-16]] laboratory aircraft, no. 3709, equipped for monitoring the tests, and its crew:<ref name=Chernyshev/>

* 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 special reflective paint to minimize heat damage. Despite this, Durnovtsev and his crew were given only a 50% chance of surviving the test.<ref name="ctbto">{{cite web |title=30&nbsp;October 1961 – The Tsar Bomba |publisher=CTBTO Preparatory Commission |url=https://www.ctbto.org/specials/testing-times/30-october-1961-the-tsar-bomba/ |access-date=26 July 2016}}</ref><ref name=":1">{{Cite web|last=Dowling|first=Stephen|title=The monster atomic bomb that was too big to use| url=https://www.bbc.com/future/article/20170816-the-monster-atomic-bomb-that-was-too-big-to-use|access-date=2020-08-26|website=www.bbc.com|date=16 August 2017 |language=en}}</ref>

The bomb, weighing {{convert|27|t|ST|0}}, was so large ({{cvt|8|m}} long by {{cvt|2.1|m}} in diameter) that the Tu-95V had to have its [[bomb bay]] doors and fuselage [[fuel tank]]s removed.<ref name=atomicheritage>{{cite web |title=Tsar Bomba |url=https://www.atomicheritage.org/history/tsar-bomba |publisher=[[Atomic Heritage Foundation]] |access-date=29 July 2016}}</ref><ref name=":1" /> The bomb was attached to an {{convert|800|kg|adj=on}}, {{convert|1600|m2|adj=on}} [[parachute]], which gave the release and observer planes time to fly about {{cvt|45|km}} away from [[ground zero]], giving them a 50&nbsp;percent chance of survival.<ref name=":0" /> The bomb was released two hours after takeoff from a height of {{cvt|10500|m|0}} on a test target within [[Sukhoy Nos]]. The Tsar Bomba detonated at 11:32 (or 11:33; USGS earthquake monitors list the event as occurring at 11:33:31<ref>{{cite web|url=https://earthquake.usgs.gov/earthquakes/eventpage/official19611031083331000_-4/executive|title=M 5.8 Nuclear Explosion - Novaya Zemlya, Russia|website=earthquake.usgs.gov}}</ref>) [[Moscow Time]] on 30 October 1961, over the [[Mityushikha Bay]] nuclear testing range (Sukhoy Nos Zone&nbsp;C), at a height of {{cvt|4200|m|0}} [[Height above mean sea level|ASL]] ({{cvt|4000|m|0}} above the target)<ref name="Sakharov memoirs" /><ref name="Nuclearweaponarchive.com" /><ref name="Adamsky and Smirnov" />{{refn|Some sources suggest {{cvt|3900|m|0}} ASL and {{cvt|3700|m|0}} above target, or {{cvt|4500|m|0}}.|group=Notes}} By this time the Tu-95V had already escaped to {{cvt|39|km}} away, and the Tu-16 {{cvt|53.5|km}} away. When detonation occurred, the [[shock wave]] caught up with the Tu-95V at a distance of {{cvt|115|km}} and the Tu-16 at {{cvt|205|km}}. After the shock wave reached the aircraft, the Tu-16 had its speed increased in a split second from 880 to 980&nbsp;km/h, and dropped {{convert|800|m}} in the air due to the combination of the shock wave with exceptionally high air density [[rarefaction|drop]] immediately afterwards. However, both aircraft managed to recover and land safely.<ref name="ctbto" /> According to initial data, the Tsar Bomba had a nuclear yield of {{cvt|58.6|MtonTNT}} (exceeding what the design itself would suggest) and was overestimated at values all the way up to {{cvt|75|MtonTNT}}. Both aircraft had their frames burned-out black by the radiation in all parts exposed to the blast.

[[File:Tsar Bomba fireball.jpg|thumb|right|The Tsar Bomba's fireball, about {{cvt|8|km|mi|0}} wide at its maximum, was prevented from touching the ground by the shock wave, but reached nearly {{cvt|10.5|km|ft}} in the sky – the altitude of the deploying bomber.]]

Although simplistic [[effects of nuclear explosions|fireball]] calculations predicted it would be large enough to hit the ground, the bomb's own shock wave bounced back and prevented this.<ref name="nuclearweaponarchive"/> The {{convert|8|km|mi|-wide|adj=mid}} fireball reached nearly as high as the altitude of the release plane and was visible at almost {{cvt|1000|km}} away.<ref name="RichardtHülseweh2013">{{cite book |first1=Andre |last1=Richardt |first2=Birgit |last2=Hülseweh |first3=Bernd |last3=Niemeyer |first4=Frank |last4=Sabath |title=CBRN Protection: Managing the Threat of Chemical, Biological, Radioactive and Nuclear Weapons |url=https://books.google.com/books?id=di3b6nDwvq4C&pg=PT14 |access-date=4 August 2018 |date=1 March 2013 |publisher=John Wiley & Sons |isbn=978-3-527-65018-7 |page=14}}</ref> The [[mushroom cloud]] was about {{cvt|67|km}} high<ref>{{cite magazine |last=Veselov |first=A.V. |title=Tsar-bomba |magazine=Atompress |year=2006 |volume=43 |issue=726 |page=7}}</ref> (nearly eight times the height of [[Mount Everest]]), which meant that the cloud was above the [[stratosphere]] and well inside the [[mesosphere]] when it peaked. The base was {{cvt|40|km}} wide.<ref>{{cite news |url=http://www.pravdareport.com/history/17-09-2009/109339-tsar_bomba-0/ |title=Tsar Bomba's blast wave orbited Earth three times in 1961 |date=17 September 2009 |work=[[Pravda]] |access-date=24 November 2016 |archive-date=25 November 2016 |archive-url=https://web.archive.org/web/20161125043146/http://www.pravdareport.com/history/17-09-2009/109339-tsar_bomba-0/ |url-status=dead }}</ref>

A Soviet cameraman said:<blockquote>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.<ref name="nuclearweaponarchive"/></blockquote>

== Test results ==
The explosion of Tsar Bomba, according to the classification of [[nuclear explosion]]s, was an ultra-high-power low-air nuclear explosion.{{cn|date=September 2024}}

[[File:Tsar photo11.jpg|thumb|right|The [[mushroom cloud]] of Tsar Bomba seen from a distance of {{cvt|161|km}}. The crown of the [[cloud]] is {{cvt|65|km|mi}} high at the time of the picture. (source: Rosatom State Corporation Communications Department 20–08–2020)]]

* The flare was visible at a distance of more than {{cvt|1000|km}}.<ref name="vniief.ru">{{cite web|url=http://www.vniief.ru/about/history/nextresearch/ |title=Дальнейшие разработки атомного оружия |access-date=10 December 2020}}</ref> It was observed in Norway, Greenland and Alaska.<ref name=Chernyshev/>
* The explosion's mushroom cloud rose to a height of {{cvt|67|km}}.<ref name="Veselov, A.V. 2006 7"/> The shape of the "hat" was two-tiered; the diameter of the upper tier was estimated at {{cvt|95|km}}, the lower tier at {{cvt|70|km}}. The cloud was observed {{cvt|800|km}} from the explosion site.<ref name=Chernyshev/>
* The blast wave circled the globe three times,<ref name=Chernyshev/> with the first one taking 36 hours and 27 minutes.<ref name="Книга рекордов Гиннесса, 1993">{{cite book |title=Книга рекордов Гиннесса 1993 |location=Москва−Лондон | publisher=Сов. Россия, Moskva |year=1993 |pages=198 }}</ref>
* A seismic wave in the Earth's crust, generated by the shock wave of the explosion,  also circled the globe three times.<ref name="vniief.ru"/>
* 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 30 October, coming from the north-west, at 07:17 on 31 October, from the southeast, and at 09:16, on 1 November, from the northwest (all [[Greenwich Mean Time|GMT]]), with amplitudes of {{cvt|0.6|mbar|lk=on}}, {{cvt|0.4|mbar}}, and {{cvt|0.2|mbar}} respectively. The average wave speed is estimated at {{cvt|303|m/s}}, or 9.9 degrees of the [[great circle]] per hour.<ref>{{cite journal|url=https://www.nature.com/articles/193765a0 |title=Transit of Pressure Waves through New Zealand from the Soviet 50 Megaton Bomb Explosion |year=1962 |doi=10.1038/193765a0 |access-date=10 December 2020|last1=Farkas |first1=E. |journal=Nature |volume=193 |issue=4817 |pages=765–766 |bibcode=1962Natur.193..765F |s2cid=4286997 |url-access=subscription }}</ref>
* Glass shattered in windows {{cvt|780|km}} from the explosion in a village on [[Dikson Island]].<ref name=Chernyshev/>
* The sound wave generated by the explosion reached Dikson Island, but there are no reports of destruction or damage to structures even in the [[urban-type settlement]] of [[Amderma]], which is {{cvt|520|km}} to the landfall.<ref>{{cite web|url=http://www.iss.niiit.ru/sssr2/4_4.htm |title=ЯДЕРНЫЕ ИСПЫТАНИЯ СССР том II |archive-url=https://web.archive.org/web/20070707043631/http://www.iss.niiit.ru/sssr2/4_4.htm |access-date=10 December 2020|archive-date=7 July 2007 }}</ref>
* Ionization of the atmosphere caused interference to radio communications even hundreds of kilometers from the test site for about 40 minutes.<ref>{{cite book|author=Широкорад, А. Б. |title=Вооружение советской авиации 1941–1991}}</ref> 
* Radioactive contamination of the experimental field with a radius of {{cvt|2|–|3|km}} in the [[hypocenter]] area was no more than 1 [[Roentgen (unit)|milliroentgen]] / hour. The testers appeared at the explosion site 2 hours later; radioactive contamination posed practically no danger to the test participants.<ref name=Chernyshev/>
*In the Norwegian border village of [[Kiberg]], fishermen reported injured [[cod]], and border guards reported having contracted [[cancer]] in large numbers over the following years, though the latter was never confirmed as being as a result of the bomb.<ref>{{Cite web|url=https://www.nrk.no/tromsogfinnmark/xl/tsar-bomben-ble-sprengt-bare-80-mil-fra-vardo-1.14588347|title=– Pappa lurte på hvordan det skulle gå med oss når Sovjet sprengte atombomber 80 mil unna|language=nb|date=27 November 2019|access-date=3 January 2024|publisher=[[NRK]]}}</ref>

All buildings in the village of Severny, both wooden and brick, located {{cvt|55|km}} 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 at a distance of {{cvt|270|km}}. The heat from the [[explosion]] could have caused [[Burn|third-degree burns]] {{cvt|100|km}} away from ground zero. A shock wave was observed in the air at [[Dikson (urban-type settlement)|Dikson settlement]] {{cvt|700|km}} away; windowpanes were partially broken for distances up to {{convert|900|km}}.<ref>{{cite web |title=Big Ivan, The Tsar Bomba ("King of Bombs") |url=http://nuclearweaponarchive.org/Russia/TsarBomba.html |date=4 September 2007 |access-date=12 June 2014}}</ref> [[Atmospheric focusing]] caused blast damage at even greater distances, breaking windows in Norway and Finland.<ref>{{cite news|url=https://www.bbc.com/news/world-asia-41140491 |title=The most powerful nuclear blasts ever |work=BBC News |date=3 September 2017 |access-date= 5 December 2020}}</ref> Despite being detonated {{cvt|4.2|km|0}} above ground, its [[body wave magnitude|seismic body wave magnitude]] was estimated at 5.0–5.25.<ref name=ctbto/><ref name="nuclearweaponarchive">{{cite web |url=http://www.nuclearweaponarchive.org/Russia/TsarBomba.html |title=The Tsar Bomba ("King of Bombs") |publisher=Nuclear Weapons Archive |quote=Despite being exploded in the atmosphere, it generated substantial seismic signals. According to a bulletin of the U.S. Geological Survey it had seismic magnitude ''m''<sub>b</sub> = 5.0 to 5.25&nbsp;. ... from fireball radius scaling laws, one would expect the fireball to reach down and engulf the ground ... In fact, the shock wave reaches the ground ... and bounces upward, striking the bottom of the fireball, preventing actual contact with the ground. |access-date=10 October 2010}}</ref>

==Reactions==
Immediately after the test, several United States politicians 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.<ref>{{cite news |url=https://www.newspapers.com/image/141601529/ |title=Blast Assailed on Capitol Hill as Soviet Act of Intimidation |date=30 October 1961 |newspaper=[[St. Louis Post-Dispatch]] |agency=[[Associated Press]] |page=2 |access-date=24 November 2016 |via=Newspapers.com}}</ref> The [[British Foreign Office]], Prime Minister of Norway [[Einar Gerhardsen]], Prime Minister of Denmark [[Viggo Kampmann]] and others also released statements condemning the blast. Soviet and [[China National Radio|Chinese radio stations]] mentioned the US underground nuclear test of [[Operation Nougat|a much smaller bomb (possibly the ''Mink'' test)]] carried out the day prior, without mentioning the Tsar Bomba test.<ref>{{Cite news |url=https://www.newspapers.com/image/141601529/ |title=Non-red world deplores test of Soviet Bomb |date=30 October 1961 |newspaper=St. Louis Post-Dispatch |page=2 |via=Newspapers.com}}</ref>

== Consequences of the test ==

The creation and testing of a superbomb were 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, [[Castle Bravo]], had been 15 Mt). After the Tsar Bomba test, the United States did not increase the power of its own thermonuclear tests and, in 1963 in Moscow, the [[Partial Nuclear Test Ban Treaty|Treaty Banning Nuclear Weapon Tests in the Atmosphere, Outer Space and Under Water]] was signed.<ref name=Chernyshev/>

The main scientific result of the test was the experimental verification of the principles of calculation and design of multistage thermonuclear charges. It also confirmed the theory that there is no fundamental limit to the power of a thermonuclear charge. This fact had probably been first postulated in October 1949 (three years before the [[Ivy Mike]] test which utilized the [[Teller-Ulam]] design<ref>{{Cite web|url=http://large.stanford.edu/courses/2015/ph241/singh-a1/|title=Ivy Mike: How to Wipe Out an Island|website=large.stanford.edu}}</ref>), when in the supplement to the official report of the General Advisory Committee of the [[United States Atomic Energy Commission|US Atomic Energy Commission]], nuclear physicists [[Enrico Fermi]] and [[Isidor Isaac Rabi]] stated that thermonuclear weapons can potentially have "unlimited destructive power".<ref>{{cite book
 |last=Дайсон|first= Фримен|title= Оружие и надежда|language= en|orig-date=1984|location =М.|publisher=Прогресс|year=1990|pages=41–42|isbn= 5-01-001882-9}}</ref><ref>{{cite web |last1=Fermi |first1=Enrico |last2=Rabi |first2=Isidor Isaac |title=General Advisory Committee's Majority and Minority Reports on Building the H-Bomb |url=https://www.atomicarchive.com/resources/documents/hydrogen/gac-report.html |publisher=General Advisory Committee to the U.S. Atomic Energy Commission |date=October 30, 1949}}</ref>

The explosive power of the bomb could have easily been raised by another 50 Mt by using a uranium-238 sheath instead of lead.<ref name=nweapon.ru/> It was consciously decided to replace the cladding material and thus decrease the yield in order to reduce radioactive fallout below an acceptable level.<ref name=Chernyshev/>

The explosion is 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 Mt,<ref name=nweapon.ru/> which produced a large amount of radioactive fallout, but more than 97% of the explosion power was provided by a thermonuclear fusion reaction, which does not create a significant amount of radioactive contamination.<ref>{{cite web|url=http://elib.biblioatom.ru/text/atomny-proekt-sssr_t3_kn2_2009/go,440/ |title=Note by A. D. Sakharov, Ya. B. Zel'dovich and V. A. Davidenko to N. I. Pavlov with an estimate of the parameters of products with a capacity of 150 megatons and one billion tons of TNT |access-date=10 December 2020}}</ref>

A 2015 expedition measuring the glaciers of Novaya Zemlya reported 65–130 times more radioactivity than the background in neighboring areas, due to nuclear testing, including Tsar Bomba.<ref>{{cite web |url=https://www.gazeta.ru/science/2015/11/30_a_7921283.shtml |title="Кузькина мать" до сих пор фонит |access-date=10 December 2020}}</ref>

[[Andrei Sakharov]] was one of the most prominent speakers against nuclear proliferation. He played a key role in signing the 1963 Partial Test Ban Treaty. Sakharov became an advocate of civil liberties and reforms in the Soviet Union. In 1973 he was nominated for the [[Nobel Peace Prize]] and in 1974 was awarded the [[Prix mondial Cino Del Duca]]. He won the Nobel Peace Prize in 1975, but was not allowed to leave the Soviet Union to collect it. His wife Yelena Bonner read his speech at the acceptance ceremony.{{citation needed|date=August 2023}}

== Analysis ==
[[File:Tsar Bomba Paris.png|thumb|Total destructive radius, superimposed on [[Paris]] with the red circle indicating the area of total destruction (radius {{convert|35|km|mi|0|disp=sqbr}}), and the yellow circle the radius of the fireball (radius {{convert|3.5|km|mi|0|disp=sqbr}})]]
The Tsar Bomba is the single most physically powerful device ever deployed on Earth, the most powerful nuclear bomb tested and the largest human-made explosion in history.<ref>{{cite web |last=Sudakov |first=Dmitry |date=24 September 2009 |title=Tsar Bomba's Blast Wave Orbited Earth Three Times in 1961 |url=http://english.pravda.ru/russia/history/17-09-2009/109339-tsar_bomba-0 |access-date=24 September 2009 |publisher=Pravda.ru}}</ref> For comparison, the largest weapon ever produced by the US, the now-decommissioned [[B41 nuclear bomb|B41]], had a predicted maximum yield of {{cvt|25|MtonTNT}}. The largest nuclear device ever tested by the US ([[Castle Bravo]]) yielded {{cvt|15|MtonTNT}} because of an unexpectedly high involvement of [[Isotopes of lithium#Lithium-7|lithium-7]] in the fusion reaction; the preliminary prediction for the yield was from {{cvt|4|to|6|MtonTNT}}. The largest weapons deployed by the Soviet Union were also around {{cvt|25|MtonTNT}} (e.g., the [[R-36 (missile)|SS-18]] Mod.&nbsp;3 [[warhead]]).<ref name=atomicheritage/>

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 (rocket family)|Proton]] started its development as that delivery system). It has been estimated that detonating the original {{cvt|100|MtonTNT}} design would have increased the world's total fission fallout since the invention of the atomic bomb by 25%.<ref>{{cite web |url=http://nuclearweaponarchive.org/Russia/Sovwarhead.html |title=Soviet Nuclear Weapons |work=nuclearweaponarchive.org}}</ref> It was decided that a full 100&nbsp;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.<ref>{{cite web |url=http://www.atomicforum.org/russia/tsarbomba.html |title=Tsar Bomba |access-date=3 November 2007 |publisher=Atomic Forum |archive-url=https://web.archive.org/web/20071204024711/http://www.atomicforum.org/russia/tsarbomba.html |archive-date=4 December 2007 }}</ref>

The Tsar Bomba was the culmination of a series of high-yield [[thermonuclear weapon]]s designed by the Soviet Union and the United States during the 1950s (e.g., the [[Mark 17 nuclear bomb|Mark&nbsp;17]]{{citation needed|date=February 2023}} and B41 nuclear bombs).<ref name=atomicheritage />

== Practical applications ==
The Tsar Bomba was never intended to be a practical or mass-produced weapon; it was a single product, the design of which allowed reaching a power of 100 Mt. The test of a 50-Mt bomb was, among other things, a test of the performance of the product design for 100 Mt.<ref name="rc.nsu.ru"/> However, there were several "super-heavy" ballistic missiles that were developed by the Soviet Union whose early impetus was at least partially, if not entirely, designed to give them a capability to use warheads in the 50-150 Mt range. These included:

* UR-500 – (warhead mass – 40 tons, virtually implemented as a carrier rocket – "[[Proton (rocket family)|Proton]]" – GRAU index – 8K82)
* [[N1 (rocket)|N-1]] – (warhead mass – {{cvt|75|–|95|t|0}}, the development was reoriented into a carrier for the [[Soviet crewed lunar programs|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)<ref>{{cite journal| last= Первов |first= Михаил |title= Ракетные комплексы РВСН |journal= Техника и вооружение |date= 2001 |volume= 5—6 |pages= 44}}</ref>

In the absence of a push for such high-yield weapons, all of these rocket programs were either used as launch vehicles for the Soviet space program, or cancelled.

== Films ==

* 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''.<ref>{{cite web |url=http://nuclearweaponarchive.org/News/VCE.html |title=Trinity and Beyond: The Atomic Bomb Movie |publisher=Nuclear Weapon Archive |date=15 August 1999}}</ref> The video has a few inaccuracies: It states that the ''Tsar Bomba'' project broke the voluntary [[Moratorium (law)|moratorium]] on nuclear tests. In fact, the Soviets had restarted their test program and broken the unilateral voluntary moratorium 30&nbsp;days before ''Tsar Bomba'', testing 45&nbsp;times in that month. Since the moratorium was unilateral there was no 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.<ref name="Sherman, Robert 2008">{{cite web |last=Sherman |first=Robert |url=https://fas.org/nuke/control/ctbt/chron1.htm |title=Comprehensive Test Ban Treaty Chronology |publisher=[[Federation of American Scientists]] |date=30 May 2008}}</ref> That was incorrect, as the US had in fact tested five times under [[Operation Nougat]] between the USSR's ending of the moratorium on 1&nbsp;October and the Tsar Bomba test on 30&nbsp;October.
* "World's Biggest Bomb", a 2011 episode of the [[PBS]] documentary series ''[[Secrets of the Dead#Season 10 (2010–2011)|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 Russian language documentary video of the Tsar Bomba test on [[YouTube]] in August 2020.<ref>{{cite web |url=https://thebarentsobserver.com/en/security/2020/08/rosatom-releases-previously-classified-documentary-video-50-mt-novaya-zemlya-test |title=Rosatom releases previously classified documentary video of Tsar Bomba nuke test |first=Thomas |last=Nilsen |date=22 August 2020 |access-date=23 August 2020 |publisher=The Barents Observer}}</ref>

== See also ==
* [[Father of All Bombs]] – largest Russian conventional bomb
* [[Soviet atomic bomb project]]
* [[Doomsday device]]
* [[Sundial (weapon)]]

== Notes ==
{{Reflist|group=Notes}}

== References ==
{{Reflist}}

== External links ==
{{Commons}}
* {{cite web |url=http://www.nuclearweaponarchive.org/Russia/TsarBomba.html |title=Tsar Bomba |editor-first=Carey |editor-last=Sublette |website=NuclearWeaponArchive.org |date=30 October 2018}}
* {{cite AV media |medium=video |url=http://sonicbomb.com/modules.php?name=Content&pa=showpage&pid=90 |archive-url=https://archive.today/20121209133032/http://sonicbomb.com/modules.php?name=Content&pa=showpage&pid=90 |url-status=dead |archive-date=9 December 2012 |title=Video of the Tsar Bomba delivery, blast and cloud }}{{cite web |title=Sonicbomb.com |url=http://sonicbomb.com/modules.php?name=Content&pa=showpage&pid=39 |archive-url=https://archive.today/20121205014623/http://sonicbomb.com/modules.php?name=Content&pa=showpage&pid=39 |url-status=dead |archive-date=5 December 2012 }}
<!-- not needed: there is a uniform ~geohack link -- *[http://maps.google.com/?ie=UTF8&ll=73.807093,54.981766&spn=0.005852,0.037594&t=h&z=15&lci=lmc:wikipedia_en Google Maps] -->

{{Soviet nuclear weapons}}
{{Russian and Soviet Aircraft Ordnance}}
{{Portal bar|Nuclear technology|Soviet Union}}

{{Coord|73|48|26|N|54|58|54|E|type:event_region:RU|display=title}}

[[Category:1961 in military history]]
[[Category:1961 in science]]
[[Category:1961 in the Soviet Union]]
[[Category:Explosions in 1961]]
[[Category:Cold War weapons of the Soviet Union]]
[[Category:Novaya Zemlya]]
[[Category:Nuclear bombs of the Soviet Union]]
[[Category:Russian inventions]]
[[Category:Soviet inventions]]
[[Category:Soviet nuclear weapons testing]]
[[Category:October 1961 in Europe]]
[[Category:October 1961 in Asia]]