Tsar Bomba (Царь-бомба, "Tsar of Bombs"; project designation AN602, popularly nicknamed Kuzka's Mother) was a Soviet thermonuclear bomb exploded over the Arctic archipelago of Novaya Zemlya on 30 October 1961. With a yield of about 50 megatons of TNT — some 3,300 times the power of the bomb dropped on Hiroshima — it was the most powerful nuclear weapon ever detonated.[2][3][12] The bomb was designed and assembled at Arzamas-16,[1] the secret nuclear-weapons laboratory in the closed town of Sarov (Саров), in the south of the Nizhny Novgorod Region of Russia.[11] The region is named after its capital, Nizhny Novgorod — a large city on the Volga, which from 1932 to 1990 was called Gorky.

The design work was led by Andrei Sakharov, who in later years became the Soviet Union's best-known dissident and was exiled to Gorky; much of the design was done by two young physicists of the institute, Yuri Trutnev and Yuri Babaev. A casing of the bomb has been on display since 1992 at the Museum of Nuclear Weapons in Sarov, the town where it was made.[4][5][13][16]

The largest explosion in history

On 30 October 1961 a specially modified Tu-95V strategic bomber, commanded by Andrei Durnovtsev, dropped the bomb over the Novaya Zemlya test range.[15] The weapon was about eight metres long and two metres in diameter and weighed more than 20 tonnes. It was too big for the bomber's bay, so part of the fuselage was cut away and more than half of the bomb hung outside; the aircraft was painted white to protect it from the flash. The bomb came down on a large parachute, which gave the crew time to get clear, and a special mechanism allowed it to explode only once the aircraft had reached a safe distance.[1] It burst about 4,000 metres above the ground.[12]

The Sarov designers put the yield at 50 megatons; the United States later announced that it might have been as high as 57 or 58.[2][4] According to VNIIEF, the institute that made the bomb, the flash was visible more than 1,000 kilometres away, and the seismic wave generated by the blast travelled around the Earth three times.[3] The mushroom cloud rose to a height of about 60 kilometres.[12] The explosion released ten times the energy of all the explosives used in the Second World War, the two atomic bombs included.[1]

The device had been designed for up to 100 megatons. To halve the yield — and the fallout — the designers replaced the uranium-238 in its design with lead; 97 per cent of the energy came from fusion rather than fission, which made the explosion remarkably "clean" for its size. The test was in effect a test of the design of a 100-megaton weapon: the bomb itself was a one-off device and was never put into service.[1][4]

The same day the two men in charge of the test, Minister of Medium Machine Building Efim Slavsky and Marshal Kirill Moskalenko, cabled Nikita Khrushchev in the Kremlin: "The test at Novaya Zemlya was a success… We are returning for the Congress." The 22nd Congress of the Communist Party was then in session in Moscow.[1]

Made in Arzamas-16

The bomb was the work of KB-11 (Design Bureau No. 11), founded in 1946 in the small settlement of Sarov to build the first Soviet atomic bomb; today it is the Russian Federal Nuclear Center — All-Russian Research Institute of Experimental Physics (RFNC-VNIIEF), part of the state corporation Rosatom.[9] The town that grew up around it did not appear on Soviet maps. Its secret name was Kremlyov (Кремлёв); its postal addresses, Arzamas-75 and then Arzamas-16, borrowed the name of the old town of Arzamas nearby; the town regained the name Sarov only in 1995.[10] Sarov is still a closed town — a "closed administrative-territorial formation" with restricted entry — lying on the border with the Republic of Mordovia; in 2020 it had more than 96,000 inhabitants.[11] In 1961 the institute's scientific director was Yuliy Khariton, who had headed KB-11 since its foundation.[9]

On 10 July 1961 Khrushchev summoned the nuclear scientists of Arzamas-16 to the Kremlin and told them that the Soviet Union would resume nuclear testing; Sakharov, who argued that new tests were unnecessary, was angrily rebuffed.[4] Work on the "superbomb" began in the middle of July.[1] The designers did not start from scratch: the huge ballistic casing of an earlier 100-megaton project, RDS-202, shelved in the late 1950s, had been kept in storage, and it became the shell of the new weapon, although the physics inside was new.[4] In August a colonel from Arzamas-16 brought a large wooden model of the bomb to a meeting in the Kremlin; he later recalled that Khrushchev stroked it for a long time.[4]

Sakharov managed the project, while Trutnev and Babaev did much of the design work.[4] The final report, with the proposed design of the bomb and its theoretical calculations, was completed by 24 October 1961. Its authors were Andrei Sakharov, Viktor Adamsky, Yuri Babaev, Yuri Smirnov and Yuri Trutnev, and its conclusion read: "A successful result from the test of this device opens the possibility of creating a device of practically unlimited power."[1]

The bomb was assembled at Arzamas-16 on a special railway flatcar standing inside the assembly shop — a railway line had to be laid right into the building — and the finished car was disguised as an ordinary goods wagon.[1] The declassified Soviet film of the test shows the 26-tonne weapon in its casing travelling by rail.[12] The pressure on the designers was considerable. On 17 October, opening the 22nd Party Congress, Khrushchev had told the world that the Soviet test series would end with "a hydrogen bomb with a yield of 50,000,000 tons of TNT", so a failure would have been a public one.[1][4] "If we don't make this thing," Sakharov remarked, "we'll be sent to railroad construction."[1]

The people of Arzamas-16

Andrei Sakharov (1921–1989) began working at KB-11 in 1950 as a member of the theoretical group of Igor Tamm, and became the central figure of the Soviet hydrogen-bomb programme. He was three times awarded the title of Hero of Socialist Labour — in 1953, 1956 and 1962.[8] Viktor Adamsky and Yuri Smirnov, who took part in the work, wrote that the 50-megaton bomb was the last device on which Sakharov worked "intensely, seriously, and without hesitation".[1]

Yuri Trutnev (1927–2021) was born in Moscow. During the Second World War his family was evacuated, first to the Urals and then to the Gorky Region; after graduating in physics from Leningrad University in 1950 he was sent to the Sarov institute, where he spent his whole career, rising to first deputy scientific director. He received the Lenin Prize in 1959 and the title of Hero of Socialist Labour in 1962, and became a full member of the Russian Academy of Sciences in 1991. Trutnev was an honorary citizen of Sarov and of the Nizhny Novgorod Region.[9][17]

Yuri Babaev (1928–1986) came to KB-11 in 1951 as a theorist in Sakharov's department. In 1955, together with Trutnev, he proposed a new principle for the design of the two-stage hydrogen charge, and in 1959 he too received the Lenin Prize for it.[7]

Viktor Adamsky worked in Sakharov's group at Arzamas-16; Yuri Smirnov later became a researcher at the Kurchatov Institute in Moscow and a historian of the Soviet nuclear project. In 1994 the two published a first-hand account of the test in English.[1]

How the world saw it

The Soviet government made no secret of the coming explosion: unusually, it announced the power of the bomb in advance, as a move in the political contest with the United States.[1] Washington called the test a political rather than a military act — "There is no mystery about producing a 50-megaton bomb," the White House said. Behind closed doors the reaction was more serious. On 18 October 1961 the chairman of the US Atomic Energy Commission, Glenn Seaborg, sent President John F. Kennedy a memo outlining an American 100-megaton weapon, although the United States never built a bomb of that size.[4]

The explosion did not lead directly to the Partial Test Ban Treaty, which ended nuclear tests in the atmosphere: negotiations went on for almost two more years, although, in the view of Adamsky and Smirnov, the test may have contributed to their success indirectly.[1]

For decades the details remained classified. In August 2020, marking the 75th anniversary of the Soviet atomic industry, Rosatom published a declassified Soviet documentary about the test. The film, about 30 minutes long and opening with a "Top secret" title, shows the bomb's journey by rail and the explosion filmed from the ground and from two aircraft; its release was reported by Reuters.[12]

From Sarov to Gorky: Sakharov's exile

Sakharov's last great weapon coincided with his growing doubts. Before the 1961 test series he sent Khrushchev a note arguing that resuming the tests would harm the test-ban negotiations, disarmament and world peace, and he worked on the "big bomb" only after Khrushchev had rejected his appeal.[1] In his own words, during those years he "was becoming ever more conscious of the moral problems inherent in this work". In 1968 he made his views public, and in 1975 he received the Nobel Peace Prize.[16]

Early in 1980, after he had denounced the Soviet invasion of Afghanistan, Sakharov was exiled to Gorky, where he lived isolated and under KGB pressure until 1986, when he and his wife Elena Bonner were allowed to return to Moscow.[16] So the scientist who led the design of the largest bomb ever exploded spent his years of exile in Gorky, the capital of the region in which Sarov lies. The flat in which he lived is now the Sakharov Museum.

Memory

Sarov keeps the memory of the bomb at the institute's Museum of Nuclear Weapons (Музей ядерного оружия), which opened on 13 November 1992 and describes itself as the first museum in Russia devoted to the history of the country's nuclear shield. Among its exhibits, next to the first Soviet atomic bomb RDS-1 and the first serial atomic bomb RDS-4, is "a sample of the world's most powerful experimental thermonuclear bomb, tested in 1961 over the Novaya Zemlya archipelago".[5] The first guided tour of the new museum was given by Yuri Trutnev.[6] The casing has stood there since November 1992.[13]

It is not clear who first called the bomb "Tsar Bomba". According to one account cited by the historian Alex Wellerstein, the name was proposed by Trutnev in the early 1990s, while a museum exhibition on Soviet nuclear history was being put together.[4] In August 2015 the casing was taken to Moscow for the first time, on a special trailer, as the centrepiece of Rosatom's exhibition marking 70 years of the nuclear industry, held from 1 to 29 September in the Manege, next to the Kremlin walls.[13][14]

The town also remembers the bomb's makers: among the Sarov streets named after the scientists of the nuclear centre are streets of Andrei Sakharov and Yuliy Khariton.[18]

Names

The bomb's official designation was AN602.[14] Its Russian nickname, Kuzkina mat' ("Kuzka's mother"), is believed to come from Khrushchev's words to the US Vice President Richard Nixon in 1959: "We will show you Kuzka's mother!" — a Russian folk threat meaning roughly "we'll show you what's what". The other nickname, "Tsar Bomba", stresses that it was the most powerful weapon in history.[14]

See also

Sources

  1. Woodrow Wilson International Center for Scholars — Viktor Adamsky and Yuri Smirnov, "Moscow's Biggest Bomb: The 50-Megaton Test of October 1961", Cold War International History Project Bulletin, No. 4, Fall 1994, pp. 3, 19–21 (archive)
  2. RFNC-VNIIEF — "Main achievements" of the institute, chronology (in Russian) (archive)
  3. RFNC-VNIIEF — "Further development of nuclear weapons", history of the institute (in Russian) (archive)
  4. Bulletin of the Atomic Scientists — Alex Wellerstein, "An unearthly spectacle: The untold story of the world's biggest nuclear bomb", 29 October 2021 (archive)
  5. RFNC-VNIIEF — "Museum of Nuclear Weapons" (in Russian) (archive)
  6. RFNC-VNIIEF — "History of the museum" (in Russian) (archive)
  7. RFNC-VNIIEF — "They forged the country's nuclear shield": biographies, A–G (Yuri Babaev) (in Russian) (archive)
  8. RFNC-VNIIEF — "They forged the country's nuclear shield": biographies, L–Ts (Andrei Sakharov) (in Russian) (archive)
  9. RFNC-VNIIEF — "They forged the country's nuclear shield": biographies, T–Ya (Yuri Trutnev, Yuliy Khariton) (in Russian) (archive)
  10. RFNC-VNIIEF — "History of the place's names": all the names of Sarov, from the ancient hillfort to the present town (in Russian) (archive)
  11. Administration of the Sarov urban district — "About the district": location, population (in Russian)
  12. Arctic Today — Reuters, "Russia releases secret footage of the 1961 Arctic test of 'Tsar Bomba'", 28 August 2020 (archive)
  13. AtomInfo.ru / atomic-energy.ru — "Tsar Bomba" leaves for Moscow: the casing of the AN-602 bomb taken from the VNIIEF museum to the Manege exhibition, 25 August 2015 (in Russian) (archive)
  14. Interfax — A copy of the thermonuclear "Tsar Bomba" to be shown at the exhibition in the Moscow Manege, 18 August 2015 (in Russian) (archive)
  15. Rossiyskaya Gazeta — Igor Elkov, "'Kuzka's mother' to be brought to Moscow", 20 August 2015 (in Russian) (archive)
  16. The Nobel Prize — Andrei Sakharov — Biographical (Nobel Peace Prize 1975)
  17. Argumenty i Fakty — Vladimir Gubarev, "Keeper of the nuclear fire: what Academician Trutnev believed in and valued", 8 August 2021 (in Russian) (archive)
  18. RFNC-VNIIEF — "History of Sarov": building the town around the nuclear centre (in Russian) (archive)