Editing Soviet atomic bomb project (section)

== Important nuclear tests ==
{{see also|List of nuclear weapons tests of the Soviet Union}}[[File:Soviet super test.jpg|thumb|The [[mushroom cloud]] from the<br>first air-dropped bomb test in 1951.<br>{{small|This picture is confused with [[RDS-27]] and [[RDS-37]] tests.}}]]
[[File:U. S. and USSR (now Russia) warhead levels, 1974–94.gif|thumb|250px|The Soviet program of nuclear weapons produces the stockpile {{small|(shown in black and white)}} reaching at its height in 1986 exceeding the United States stockpiles.]]

=== RDS-1 ===
The [[RDS-1]], ([[Russian language|Russian]]: PДC), was the first Soviet nuclear device that was test fired in [[Semipalatinsk Test Site|Semipalatinsk]] in [[Kazakh SSR|Kazakhstan]] on August 29, 1949. The first [[atomic test|nuclear test]], that proved the [[Russia]]'s nuclear capability, has many codenames within Russian political community including the internally code-named ''First Lightning'' (''Первая молния'', or Pervaya Molniya).

Nonetheless, the test was widely known as "RDS-1" (''Россия делает сама,'' Rossiya Delayet Sama, which translate as "Russia Does it Herself"), which was suggested by [[Igor Kurchatov]]– all Russian nuclear tests were then followed the ''RDS'' nomenclature. The [[United States|Americans]] codenamed the test as ''Joe 1''. The energy yield measurement and its design was mostly based on the American design "[[Fat Man]]", using a [[Trinitrotoluene|TNT]]/[[hexogen]] implosion lens design.

=== RDS-2 ===

The RDS-2 was a second important nuclear test that was conducted on September 24, 1951. The Soviet physicists measured the energy yield of the device at the 38.3 kiloton.<ref>Andryushin et al., "Taming the Nucleus"</ref> The U.S. codenamed the test as "Joe-2".

=== RDS-3 ===

The [[RDS-3]] was a third nuclear explosive device that was test fired on October 18, 1951, also in [[Semipalatinsk Test Site|Semipalatinsk]]. Known as ''Joe 3'' in [[United States|America]], this was a fission device using a composite construction of levitated [[plutonium core]] and a [[uranium-235]] shell with estimated blast yield of 41.2 [[TNT equivalent|kt]]. The ''RDS-3'' was also distinguished of being the first Russian air-dropped bomb test which was released at an altitude of 10&nbsp;km, it detonated 400 meters above the ground.

=== RDS-4 ===
[[RDS-4]] represented a branch of research on small tactical weapons. It used plutonium in a "levitated" core design. The first test was an air drop on August 23, 1953, yielding 28 kilotons. In 1954, the bomb was also used during [[Totskoye nuclear exercise|Snowball exercise]] at the [[Totskoye range]], dropped by [[Tupolev Tu-4|Tu-4 bomber]] on the simulated battlefield, in the presence of 40,000 infantry, tanks, and jet fighters. The RDS-4 comprised the warhead of the [[R-5 (rocket)|R-5M]], the first [[medium-range ballistic missile]] in the world, which was tested with a live warhead for the first and only time on February 5, 1956

=== RDS-5 ===
[[RDS-5]] was a small plutonium based device, probably using a hollow core. Two different versions were made and tested.

=== RDS-6s ===
[[RDS-6|RDS-6s]], the first Soviet test of a [[hydrogen bomb]], took place on August 12, 1953, and was nicknamed ''Joe 4'' by the Americans. It used a layer-cake design of fission and fusion fuels (uranium-235, lithium-6 deuteride, and lithium-6 deuteride tritide) and produced a yield of 400 kilotons. This yield was about ten times more powerful than any previous Soviet test.<ref name=":0" /> When developing higher level bombs, the Soviets proceeded with the RDS-6 concept as their main effort instead of the analog RDS-7 advanced fission bomb. This led to the third idea bomb which is the [[RDS-37]].<ref name=":0" />

=== RDS-9 ===
A much lower-power version of the RDS-4 with a 3-10 kiloton yield, the [[RDS-9]] was developed for the [[Nuclear torpedo#T-5|T-5 nuclear torpedo]]. A 3.5 kiloton underwater test was performed with the torpedo on September 21, 1955.

=== RDS-37 ===
The first Soviet test of a "true" hydrogen bomb in the megaton range was conducted on November 22, 1955. It was dubbed ''[[RDS-37]]'' by the Soviets. It was of the multi-staged, [[radiation implosion]] thermonuclear design called ''Sakharov's "Third Idea"'' in the USSR and the [[Thermonuclear weapon|Teller–Ulam design]] in the U.S.<ref name="johnstonsarchive">{{cite web|url=http://www.johnstonsarchive.net/nuclear/tests/1955USSR-1.html |title=RDS-37 nuclear test, 1955 |publisher=johnstonsarchive.net|access-date=20 May 2015}}</ref>

<!-- Deleted image removed: [[File:Rsd 37 nuclear test.JPG|left|thumb|250px|A color image of [[RDS-37]].]] -->
RDS-1, RDS-6s, and RDS-37 were all tested at the [[Semipalatinsk Test Site]] in [[Kazakhstan]].

=== Tsar Bomba (AN602) ===

The [[Tsar Bomba]] (Царь-бомба) was the largest, most powerful thermonuclear weapon ever detonated. It was a three-stage [[Teller-Ulam design|hydrogen bomb]] with a [[Nuclear weapon yield|yield]] of about 50 [[TNT equivalent|megatons]].<ref>The yield of the test has been estimated between 50 and 57.23 megatons by different sources over time. Today all Russian sources use 50 megatons as the official figure. See the section "Was it 50 Megatons or 57?" at {{cite web |title=The Tsar Bomba ("King of Bombs") |url=http://www.nuclearweaponarchive.org/Russia/TsarBomba.html |access-date=11 May 2006}}</ref> This is equivalent to ten times the amount of all the explosives used in World War II combined.<ref>DeGroot, Gerard J. ''The Bomb: A Life''. Cambridge, Massachusetts: Harvard University Press, 2005. p. 254.</ref> It was detonated on October 30, 1961, in the [[Novaya Zemlya]] [[archipelago]], and was capable of approximately 100 [[megatons]], but was purposely reduced shortly before the launch. Although [[weapon]]ized, it was not entered into service; it was simply a demonstrative testing of the capabilities of the Soviet Union's military technology at that time. The heat of the explosion was estimated to potentially inflict [[third degree burn]]s at 100&nbsp;km distance of clear air.<ref name="NWA-Tsar_Bomba">{{cite web|url=http://www.nuclearweaponarchive.org/Russia/TsarBomba.html|title=The Soviet Weapons Program&nbsp;– The Tsar Bomba|date=3 September 2007|work=NuclearWeaponArchive.org|publisher=The Nuclear Weapon Archive|access-date=23 August 2010}}</ref>

=== Chagan ===

[[Chagan (nuclear test)|Chagan]] was a shot in the [[Nuclear Explosions for the National Economy]] (also known as Project 7), the Soviet equivalent of the US ''[[Operation Plowshare]]'' to investigate [[Peaceful nuclear explosions|peaceful uses of nuclear weapons]]. It was a subsurface detonation. It was fired on January 15, 1965. The site was a dry bed of the river [[Chagan River (tributary of Irtysh River)|Chagan]] at the edge of the [[Semipalatinsk Test Site]], and was chosen such that the lip of the crater would dam the river during its high spring flow. The resultant crater had a diameter of 408 meters and was 100 meters deep. A major lake (10,000&nbsp;m<sup>3</sup>) soon formed behind the 20–35&nbsp;m high upraised lip, known as ''[[Chagan Lake (Kazakhstan)|Chagan Lake]]'' or ''Balapan Lake''.{{Citation needed|date=March 2008}}

The photo is sometimes confused with [[RDS-1]] in literature.