Misplaced Pages

#293706

143-648: The Crawlerway was originally designed to support the weight of the Saturn V rocket and its payload, plus the Launch Umbilical Tower and mobile launcher platform , atop a crawler-transporter during the Apollo program . It was also used from 1981 to 2011 to transport the lighter Space Shuttles to their launch pads. Construction of the Crawlerway connected Merritt Island with the mainland, forming

286-410: A hohlraum or radiation case. The "George" shot of Operation Greenhouse of 9 May 1951 tested the basic concept for the first time on a very small scale. As the first successful (uncontrolled) release of nuclear fusion energy, which made up a small fraction of the 225  kt (940  TJ ) total yield, it raised expectations to a near certainty that the concept would work. On 1 November 1952,

429-736: A secondary section that consists of fusion fuel . The energy released by the primary compresses the secondary through the process of radiation implosion , at which point it is heated and undergoes nuclear fusion . This process could be continued, with energy from the secondary igniting a third fusion stage; the Soviet Union's AN602 " Tsar Bomba " is thought to have been a three-stage fission-fusion-fusion device. Theoretically by continuing this process thermonuclear weapons with arbitrarily high yield could be constructed. This contrasts with fission weapons, which are limited in yield because only so much fission fuel can be amassed in one place before

572-521: A crewed spacecraft to the Moon. During these revisions, the team rejected the single engine of the V-2's design and moved to a multiple-engine design. The Saturn V's final design had several key features. F-1 engines were chosen for the first stage, while new liquid hydrogen propulsion system called J-2 for the second and third stage. NASA had finalized its plans to proceed with von Braun's Saturn designs, and

715-430: A design could not produce thermonuclear weapons whose explosive yields could be made arbitrarily large (unlike U.S. designs at that time). The fusion layer wrapped around the fission core could only moderately multiply the fission energy (modern Teller–Ulam designs can multiply it 30-fold). Additionally, the whole fusion stage had to be imploded by conventional explosives, along with the fission core, substantially increasing

858-498: A dozen megatons, which was generally considered enough to destroy even the most hardened practical targets (for example, a control facility such as the Cheyenne Mountain Complex ). Even such large bombs have been replaced by smaller yield nuclear bunker buster bombs. For destruction of cities and non-hardened targets, breaking the mass of a single missile payload down into smaller MIRV bombs in order to spread

1001-401: A dry mass of about 303,000 pounds (137,000 kilograms); when fully fueled at launch, it had a total mass of 4,881,000 pounds (2,214,000 kilograms). The S-IC was powered by five Rocketdyne F-1 engines arrayed in a quincunx . The center engine was held in a fixed position, while the four outer engines could be hydraulically turned with gimbals to steer the rocket. In flight, the center engine

1144-456: A few specific incidents outlined in a section below. The basic principle of the Teller–Ulam configuration is the idea that different parts of a thermonuclear weapon can be chained together in stages, with the detonation of each stage providing the energy to ignite the next stage. At a minimum, this implies a primary section that consists of an implosion-type fission bomb (a "trigger"), and

1287-453: A high-yield explosion. A W88 warhead manages to yield up to 475 kilotonnes of TNT (1,990 TJ) with a physics package 68.9 inches (1,750 mm) long, with a maximum diameter of 21.8 inches (550 mm), and by different estimates weighing in a range from 175 to 360 kilograms (386 to 794 lb). The smaller warhead allows more of them to fit onto a single missile and improves basic flight properties such as speed and range. The idea of

1430-488: A massive effort was mounted to re-invent the process. An impurity crucial to the properties of the old Fogbank was omitted during the new process. Only close analysis of new and old batches revealed the nature of that impurity. The manufacturing process used acetonitrile as a solvent , which led to at least three evacuations of the Fogbank plant in 2006. Widely used in the petroleum and pharmaceutical industries, acetonitrile

1573-399: A more compact size, a lower mass, or a combination of these benefits. Characteristics of nuclear fusion reactions make possible the use of non-fissile depleted uranium as the weapon's main fuel, thus allowing more efficient use of scarce fissile material such as uranium-235 ( U ) or plutonium-239 ( Pu ). The first full-scale thermonuclear test ( Ivy Mike )

SECTION 10

#1732772755294

1716-567: A peninsula. The main vehicle access road to and from the launch pads, the Saturn Causeway, runs alongside the Crawlerway. The Crawlerway is composed of two 40-foot-wide (12 m) lanes, separated by a 50-foot (15 m) median. The top layer is Alabama river rock, 4 inches (10 cm) thick on the straight sections and 8 inches (20 cm) thick on curves. Alabama river rock was chosen for many properties, including hardness, roundness, sphericity and LA abrasion test score . Beneath that

1859-576: A possibility. It was first used in thermonuclear weapons with the W76 thermonuclear warhead and produced at a plant in the Y-12 Complex at Oak Ridge, Tennessee , for use in the W76. Production of Fogbank lapsed after the W76 production run ended. The W76 Life Extension Program required more Fogbank to be made. This was complicated by the fact that the original Fogbank's properties were not fully documented, so

2002-513: A proposed replacement for the first stage was the AJ-260x . This solid rocket motor would have simplified the design by removing the five-engine configuration and, in turn, reduced launch costs. The S-II was built by North American Aviation at Seal Beach, California . Using liquid hydrogen and liquid oxygen, it had five Rocketdyne J-2 engines in a similar arrangement to the S-IC, and also used

2145-461: A riskier option, as a space rendezvous had yet to be performed in Earth orbit, much less in lunar orbit. Several NASA officials, including Langley Research Center engineer John Houbolt and NASA Administrator George Low , argued that a lunar orbit rendezvous provided the simplest landing on the Moon with the most cost–efficient launch vehicle, and the best chance to accomplish the lunar landing within

2288-426: A rocket varies with air density and the square of relative velocity . Although velocity continues to increase, air density decreases so quickly with altitude that dynamic pressure falls below max q. The propellant in just the S-IC made up about three-quarters of Saturn V's entire launch mass, and it was consumed at 13,000 kilograms per second (1,700,000 lb/min). Newton's second law of motion states that force

2431-587: A second time for translunar injection (TLI). The Saturn V's instrument unit was built by IBM and was placed on top of the rocket's third stage. It was constructed at the Space Systems Center in Huntsville, Alabama . This computer controlled the operations of the rocket from just before liftoff until the S-IVB was discarded. It included guidance and telemetry systems for the rocket. By measuring

2574-560: A second. Once the rocket had lifted off, it could not safely settle back down onto the pad if the engines failed. The astronauts considered this one of the tensest moments in riding the Saturn V, for if the rocket did fail to lift off after release they had a low chance of survival given the large amounts of propellant. To improve safety, the Saturn Emergency Detection System (EDS) inhibited engine shutdown for

2717-485: A thermal barrier to keep the fusion fuel filler from becoming too hot, which would spoil the compression. If made of uranium , enriched uranium or plutonium, the tamper captures fast fusion neutrons and undergoes fission itself, increasing the overall explosive yield . Additionally, in most designs the radiation case is also constructed of a material that undergoes fission driven by fast thermonuclear neutrons. Such bombs are classified as two stage weapons. Fast fission of

2860-602: A thermonuclear fusion bomb ignited by a smaller fission bomb was first proposed by Enrico Fermi to his colleague Edward Teller when they were talking at Columbia University in September 1941, at the start of what would become the Manhattan Project . Teller spent much of the Manhattan Project attempting to figure out how to make the design work, preferring it over work on the atomic bomb, and over

3003-468: A three-man spacecraft to land directly on the lunar surface. An EOR would launch the direct-landing spacecraft in two smaller parts which would combine in Earth orbit. A LOR mission would involve a single rocket launching two spacecraft: a mother ship , and a smaller, two-man landing module which would rendezvous back with the main spacecraft in lunar orbit. The lander would be discarded and the mother ship would return home. At first, NASA dismissed LOR as

SECTION 20

#1732772755294

3146-454: A time with a delay to reduce peak acceleration further. After S-IC separation, the S-II second stage burned for 6 minutes and propelled the craft to 109 miles (175 km) and 15,647 mph (25,181 km/h), close to orbital velocity . For the first two uncrewed launches, eight solid-fuel ullage motors ignited for four seconds to accelerate the S-II stage, followed by the ignition of

3289-427: A total of just 20 minutes. Although Apollo 6 experienced three engine failures, and Apollo 13 experienced one engine shutdown, the onboard computers were able to compensate by burning the remaining engines longer to achieve parking orbit. In the event of an abort requiring the destruction of the rocket, the range safety officer would remotely shut down the engines and after several seconds send another command for

3432-528: Is 4 feet (1.2 m) of graded, crushed stone, resting on two layers of fill. By 2013, a project to repair and upgrade the Crawlerway was undertaken, the first time since it was constructed that the foundation had been repaired. Additional rock was added to the surface in June 2014. [REDACTED] Media related to Crawlerway at Wikimedia Commons Saturn V The Saturn V is a retired American super heavy-lift launch vehicle developed by NASA under

3575-404: Is equal to mass multiplied by acceleration, or equivalently that acceleration is equal to force divided by mass, so as the mass decreased (and the force increased somewhat), acceleration rose. Including gravity, launch acceleration was only 1 + 1 ⁄ 4   g , i.e., the astronauts felt 1 + 1 ⁄ 4   g while the rocket accelerated vertically at 1 ⁄ 4   g . As

3718-461: Is flammable and toxic. Y-12 is the sole producer of Fogbank. A simplified summary of the above explanation is: How exactly the energy is "transported" from the primary to the secondary has been the subject of some disagreement in the open press but is thought to be transmitted through the X-rays and gamma rays that are emitted from the fissioning primary . This energy is then used to compress

3861-487: Is omitted, by replacing the uranium tamper with one made of lead , for example, the overall explosive force is reduced by approximately half but the amount of fallout is relatively low. The neutron bomb is a hydrogen bomb with an intentionally thin tamper, allowing as many of the fast fusion neutrons as possible to escape. Current technical criticisms of the idea of "foam plasma pressure" focus on unclassified analysis from similar high energy physics fields that indicate that

4004-529: Is one order of magnitude greater than the higher proposed plasma pressures and nearly two orders of magnitude greater than calculated radiation pressure. No mechanism to avoid the absorption of energy into the radiation case wall and the secondary tamper has been suggested, making ablation apparently unavoidable. The other mechanisms appear to be unneeded. United States Department of Defense official declassification reports indicate that foamed plastic materials are or may be used in radiation case liners, and despite

4147-515: Is the Soviet early Sloika design. In essence, the Teller–Ulam configuration relies on at least two instances of implosion occurring: first, the conventional (chemical) explosives in the primary would compress the fissile core, resulting in a fission explosion many times more powerful than that which chemical explosives could achieve alone (first stage). Second, the radiation from the fissioning of

4290-426: Is the fusion fuel, usually a form of lithium deuteride , which is used because it is easier to weaponize than liquefied tritium/deuterium gas. This dry fuel, when bombarded by neutrons, produces tritium, a heavy isotope of hydrogen that can undergo nuclear fusion, along with the deuterium present in the mixture. (See the article on nuclear fusion for a more detailed technical discussion of fusion reactions.) Inside

4433-446: Is the medium by which the outside pressure (force acting on the surface area of the secondary) is transferred to the mass of fusion fuel. The proposed tamper-pusher ablation mechanism posits that the outer layers of the thermonuclear secondary's tamper-pusher are heated so extremely by the primary's X-ray flux that they expand violently and ablate away (fly off). Because total momentum is conserved, this mass of high velocity ejecta impels

Crawlerway - Misplaced Pages Continue

4576-416: Is the primary example). Such processes have resulted in a body of unclassified knowledge about nuclear bombs that is generally consistent with official unclassified information releases and related physics and is thought to be internally consistent, though there are some points of interpretation that are still considered open. The state of public knowledge about the Teller–Ulam design has been mostly shaped from

4719-552: Is thought to be a standard implosion method fission bomb, though likely with a core boosted by small amounts of fusion fuel (usually 1:1 deuterium : tritium gas) for extra efficiency; the fusion fuel releases excess neutrons when heated and compressed, inducing additional fission. When fired, the Pu or U core would be compressed to a smaller sphere by special layers of conventional high explosives arranged around it in an explosive lens pattern, initiating

4862-495: Is thought to have used multiple stages (including more than one tertiary fusion stage) in their 50 Mt (210 PJ) (100 Mt (420 PJ) in intended use) Tsar Bomba. The fissionable jacket could be replaced with lead, as was done with the Tsar Bomba. If any hydrogen bombs have been made from configurations other than those based on the Teller–Ulam design, the fact of it is not publicly known. A possible exception to this

5005-409: Is widely assumed to be beryllium , which fits that description and would also moderate the neutron flux from the primary. Some material to absorb and re-radiate the X-rays in a particular manner may also be used. Candidates for the "special material" are polystyrene and a substance called " Fogbank ", an unclassified codename. Fogbank's composition is classified, though aerogel has been suggested as

5148-409: The Apollo program for human exploration of the Moon . The rocket was human-rated , had three stages , and was powered by liquid fuel . Flown from 1967 to 1973, it was used for nine crewed flights to the Moon, and to launch Skylab , the first American space station . As of 2024, the Saturn V remains the only launch vehicle to have carried humans beyond low Earth orbit (LEO). The Saturn V holds

5291-629: The Jupiter series of rockets . The Juno I rocket launched the first American satellite in January 1958. Von Braun considered the Jupiter series of rockets to be a prototype of the upcoming Saturn series of rockets , and referred to it as "an infant Saturn". Named after the sixth planet from the Sun , the design of the various Saturn rockets evolved from the Jupiter vehicles. Between 1960 and 1962,

5434-766: The Marshall Space Flight Center (MSFC) designed a series of Saturn rockets that could be deployed for Earth orbit and lunar missions. NASA planned to use the Saturn C-3 as part of the Earth orbit rendezvous (EOR) method for a lunar mission, with at least two or three launches needed for a single landing on the Moon. However, the MSFC planned an even bigger rocket, the C-4, which would use four F-1 engines in its first stage, an enlarged C-3 second stage, and

5577-918: The Mississippi River to the Gulf of Mexico . After rounding Florida , the stages were transported up the Intra-Coastal Waterway to the Vehicle Assembly Building (originally called the Vertical Assembly Building). This was essentially the same route which would be used later to ship Space Shuttle external tanks . The S-II was constructed in California and traveled to Florida via the Panama Canal . The third stage and Instrument Unit

5720-788: The S-IVB stage and delivered less sea level thrust (78,000 pounds-force (350 kN)) than the Launch Escape System rocket (150,000 pounds-force (667 kN) sea level thrust) mounted atop the Apollo command module. The Apollo LES fired for a much shorter time than the Mercury-Redstone (3.2 seconds vs. 143.5 seconds). The Saturn V was principally designed by the Marshall Space Flight Center in Huntsville, Alabama , although numerous major systems, including propulsion systems, were designed by subcontractors. The rocket used

5863-504: The S-IVB , a stage with a single J-2 engine, as its third stage. The C-4 would only need to carry out two launches to carry out an EOR lunar mission. On January 10, 1962, NASA announced plans to build the C-5. The three-stage rocket would consist of the S-IC first stage, with five F-1 engines; the S-II second stage, with five J-2 engines; and the S-IVB third stage, with a single J-2 engine. The C-5 would undergo component testing even before

Crawlerway - Misplaced Pages Continue

6006-570: The Trident II SLBM, had a prolate primary (code-named Komodo ) and a spherical secondary (code-named Cursa ) inside a specially shaped radiation case (known as the "peanut" for its shape). The value of an egg-shaped primary lies apparently in the fact that a MIRV warhead is limited by the diameter of the primary: if an egg-shaped primary can be made to work properly, then the MIRV warhead can be made considerably smaller yet still deliver

6149-612: The W-80 the gas expansion velocity is roughly 410 km/s (41 cm/μs) and the implosion velocity 570 km/s (57 cm/μs). The pressure due to the ablating material is calculated to be 5.3  billion bars (530  trillion pascals ) in the Ivy Mike device and 64 billion bars (6.4 quadrillion pascals) in the W-80 device. Comparing the three mechanisms proposed, it can be seen that: The calculated ablation pressure

6292-547: The W47 warhead deployed on Polaris ballistic missile submarines , megaton-class warheads were as small as 18 inches (0.46 m) in diameter and 720 pounds (330 kg) in weight. Further innovation in miniaturizing warheads was accomplished by the mid-1970s, when versions of the Teller–Ulam design were created that could fit ten or more warheads on the end of a small MIRVed missile. The first Soviet fusion design, developed by Andrei Sakharov and Vitaly Ginzburg in 1949 (before

6435-557: The instrument unit . All three stages used liquid oxygen (LOX) as the oxidizer . The first stage used RP-1 for fuel, while the second and third stages used liquid hydrogen (LH2). LH2 has a higher specific energy (energy per unit mass) than RP-1, which makes it more suitable for higher-energy orbits, such as the trans-lunar injection required for Apollo missions. Conversely, RP-1 offers higher energy density (energy per unit volume) and higher thrust than LH2, which makes it more suitable for reducing aerodynamic drag and gravity losses in

6578-558: The neutron flux from the primary to prematurely begin heating the secondary, weakening the compression enough to prevent any fusion. There is very little detailed information in the open literature about the mechanism of the interstage. One of the best sources is a simplified diagram of a British thermonuclear weapon similar to the American W80 warhead. It was released by Greenpeace in a report titled "Dual Use Nuclear Technology" . The major components and their arrangement are in

6721-408: The nuclear chain reaction that powers the conventional "atomic bomb". The secondary is usually shown as a column of fusion fuel and other components wrapped in many layers. Around the column is first a "pusher- tamper ", a heavy layer of uranium-238 ( U ) or lead that helps compress the fusion fuel (and, in the case of uranium, may eventually undergo fission itself). Inside this

6864-460: The secondary . The crucial detail of how the X-rays create the pressure is the main remaining disputed point in the unclassified press. There are three proposed theories: The radiation pressure exerted by the large quantity of X-ray photons inside the closed casing might be enough to compress the secondary. Electromagnetic radiation such as X-rays or light carries momentum and exerts a force on any surface it strikes. The pressure of radiation at

7007-599: The Apollo space program gained speed. The stages were designed by von Braun's Marshall Space Flight Center in Huntsville, and outside contractors were chosen for the construction: Boeing ( S-IC ), North American Aviation ( S-II ), Douglas Aircraft ( S-IVB ), and IBM ( instrument unit ). Early in the planning process, NASA considered three methods for the Moon mission: Earth orbit rendezvous (EOR), direct ascent , and lunar orbit rendezvous (LOR). A direct ascent configuration would require an extremely large rocket to send

7150-644: The British fusion bomb, with Sir William Penney in charge of the project. British knowledge on how to make a thermonuclear fusion bomb was rudimentary, and at the time the United States was not exchanging any nuclear knowledge because of the Atomic Energy Act of 1946 . The United Kingdom had worked closely with the Americans on the Manhattan Project. British access to nuclear weapons information

7293-687: The Moon. At a height of 363 feet (111 m), the Saturn V stood 58 feet (18 m) taller than the Statue of Liberty from the ground to the torch, and 48 feet (15 m) taller than the Elizabeth Tower , which houses Big Ben at the Palace of Westminster . In contrast, the Mercury-Redstone Launch Vehicle used on Freedom 7 , the first crewed American spaceflight, was approximately 11 feet (3.4 m) longer than

SECTION 50

#1732772755294

7436-606: The S-IC from the rest of the vehicle at an altitude of about 42 miles (67 km). The first stage continued on a ballistic trajectory to an altitude of about 68 miles (109 km) and then fell in the Atlantic Ocean about 350 miles (560 km) downrange. The engine shutdown procedure was changed for the launch of Skylab to avoid damage to the Apollo Telescope Mount . Rather than shutting down all four outboard engines at once, they were shut down two at

7579-481: The S-IC, the S-II was transported from its manufacturing plant to Cape Kennedy by sea. The S-IVB stage was built by the Douglas Aircraft Company at Huntington Beach, California . It had one Rocketdyne J-2 engine and used the same fuel as the S-II. The S-IVB used a common bulkhead to separate the two tanks. It was 58.6 feet (17.86 m) tall with a diameter of 21.7 feet (6.604 m) and

7722-615: The Saturn V shared characteristics with the one carried by the Saturn IB. The Saturn V was primarily constructed of aluminum . It was also made of titanium , polyurethane , cork and asbestos . Blueprints and other plans of the rocket are available on microfilm at the Marshall Space Flight Center. The Saturn V consisted of three stages—the S-IC first stage, S-II second stage, and S-IVB third stage—and

7865-526: The Soviet Union, United Kingdom, France, China and India. The thermonuclear Tsar Bomba was the most powerful bomb ever detonated. As thermonuclear weapons represent the most efficient design for weapon energy yield in weapons with yields above 50 kilotons of TNT (210 TJ), virtually all the nuclear weapons of this size deployed by the five nuclear-weapon states under the Non-Proliferation Treaty today are thermonuclear weapons using

8008-530: The Soviets had a working fission bomb), was dubbed the Sloika , after a Russian layer cake , and was not of the Teller–Ulam configuration. It used alternating layers of fissile material and lithium deuteride fusion fuel spiked with tritium (this was later dubbed Sakharov's "First Idea"). Though nuclear fusion might have been technically achievable, it did not have the scaling property of a "staged" weapon. Thus, such

8151-498: The Soviets searched for an alternative design. The "Second Idea", as Sakharov referred to it in his memoirs, was a previous proposal by Ginzburg in November 1948 to use lithium deuteride in the bomb, which would, in the course of being bombarded by neutrons, produce tritium and free deuterium. In late 1953 physicist Viktor Davidenko achieved the first breakthrough of staging the reactions. The next breakthrough of radiation implosion

8294-673: The Teller–Ulam configuration was tested at full scale in the "Ivy Mike" shot at an island in the Enewetak Atoll , with a yield of 10.4  Mt (44  PJ ) (over 450 times more powerful than the bomb dropped on Nagasaki during World War II ). The device, dubbed the Sausage , used an extra-large fission bomb as a "trigger" and liquid deuterium—kept in its liquid state by 20 short tons (18  t ) of cryogenic equipment—as its fusion fuel, and weighed around 80 short tons (73  t ) altogether. The liquid deuterium fuel of Ivy Mike

8437-429: The Teller–Ulam design. Detailed knowledge of fission and fusion weapons is classified to some degree in virtually every industrialized country . In the United States, such knowledge can by default be classified as " Restricted Data ", even if it is created by persons who are not government employees or associated with weapons programs, in a legal doctrine known as " born secret " (though the constitutional standing of

8580-435: The U.S. and Soviets, achieving only approximately 300 kt (1,300 TJ). The second test Orange Herald was the modified fission bomb and produced 720 kt (3,000 TJ)—making it the largest fission explosion ever. At the time almost everyone (including the pilots of the plane that dropped it) thought that this was a fusion bomb. This bomb was put into service in 1958. A second prototype fusion bomb, Purple Granite ,

8723-695: The U.S. government brought the German rocket technologist Wernher von Braun and over 1,500 German rocket engineers and technicians to the United States in Operation Paperclip , a program authorized by President Truman . Von Braun, who had helped create the German V-2 rocket, was assigned to the Army's rocket design division. Between 1945 and 1958, his work was restricted to conveying

SECTION 60

#1732772755294

8866-493: The U.S. government has attempted to censor weapons information in the public press , with limited success. According to the New York Times , physicist Kenneth W. Ford defied government orders to remove classified information from his book Building the H Bomb: A Personal History . Ford claims he used only pre-existing information and even submitted a manuscript to the government, which wanted to remove entire sections of

9009-474: The United States at that time. Two main reasons for the cancellation of the last three Apollo missions were the heavy investments in Saturn V and the ever-increasing costs of the Vietnam War to the U.S. in money and resources. In the time frame from 1969 to 1971 the cost of launching a Saturn V Apollo mission was between $ 185,000,000 to $ 189,000,000, of which $ 110 million were used for the production of

9152-494: The X-ray energy impinging on its pusher/ tamper. This compresses the entire secondary stage and drives up the density of the plutonium spark plug. The density of the plutonium fuel rises to such an extent that the spark plug is driven into a supercritical state, and it begins a nuclear fission chain reaction . The fission products of this chain reaction heat the highly compressed (and thus super dense) thermonuclear fuel surrounding

9295-535: The acceleration and vehicle attitude , it could calculate the position and velocity of the rocket and correct for any deviations. After the construction and ground testing of each stage was completed, they were each shipped to the Kennedy Space Center. The first two stages were so massive that the only way to transport them was by barge. The S-IC, constructed in New Orleans, was transported down

9438-411: The amount of chemical explosives needed. The first Sloika design test, RDS-6s , was detonated in 1953 with a yield equivalent to 400 kt (1,700 TJ) ( 15%- 20% from fusion). Attempts to use a Sloika design to achieve megaton-range results proved unfeasible. After the United States tested the "Ivy Mike" thermonuclear device in November 1952, proving that a multimegaton bomb could be created,

9581-446: The book for concern that foreign states could use the information. Though large quantities of vague data have been officially released—and larger quantities of vague data have been unofficially leaked by former bomb designers—most public descriptions of nuclear weapon design details rely to some degree on speculation, reverse engineering from known information, or comparison with similar fields of physics ( inertial confinement fusion

9724-481: The casing to a plasma, which then re-radiated radiation into the secondary's pusher, causing its surface to ablate and driving it inwards, compressing the secondary, igniting the sparkplug, and causing the fusion reaction. The general applicability of this principle is unclear. In 1999 a reporter for the San Jose Mercury News reported that the U.S. W88 nuclear warhead, a small MIRVed warhead used on

9867-440: The casing's circumference. The neutron guns are tilted so the neutron emitting end of each gun end is pointed towards the central axis of the bomb. Neutrons from each neutron gun pass through and are focused by the neutron focus lens towards the centre of primary in order to boost the initial fissioning of the plutonium. A " polystyrene Polarizer/Plasma Source" is also shown (see below). The first U.S. government document to mention

10010-412: The conditions needed for fusion, and the idea of staging or placing a separate thermonuclear component outside a fission primary component, and somehow using the primary to compress the secondary. Teller then realized that the gamma and X-ray radiation produced in the primary could transfer enough energy into the secondary to create a successful implosion and fusion burn, if the whole assembly was wrapped in

10153-523: The danger of its accidentally becoming supercritical becomes too great. Surrounding the other components is a hohlraum or radiation case , a container that traps the first stage or primary's energy inside temporarily. The outside of this radiation case, which is also normally the outside casing of the bomb, is the only direct visual evidence publicly available of any thermonuclear bomb component's configuration. Numerous photographs of various thermonuclear bomb exteriors have been declassified. The primary

10296-589: The decade. Other NASA officials became convinced, and LOR was then officially selected as the mission configuration for the Apollo program and announced by NASA administrator James E. Webb on November 7, 1962. Arthur Rudolph became the project director of the Saturn V rocket program in August 1963. He developed the requirements for the rocket system and the mission plan for the Apollo program. The first Saturn V launch lifted off from Kennedy Space Center and performed flawlessly on November 9, 1967, Rudolph's birthday. He

10439-416: The decision to go forward with the development of the new weapon. Teller and other U.S. physicists struggled to find a workable design. Stanislaw Ulam , a co-worker of Teller, made the first key conceptual leaps towards a workable fusion design. Ulam's two innovations that rendered the fusion bomb practical were that compression of the thermonuclear fuel before extreme heating was a practical path towards

10582-424: The diagram, though details are almost absent; what scattered details it does include likely have intentional omissions or inaccuracies. They are labeled "End-cap and Neutron Focus Lens" and "Reflector Wrap"; the former channels neutrons to the U / Pu Spark Plug while the latter refers to an X-ray reflector; typically a cylinder made of an X-ray opaque material such as uranium with

10725-479: The doctrine has been at times called into question; see United States v. Progressive, Inc. ). Born secret is rarely invoked for cases of private speculation. The official policy of the United States Department of Energy has been not to acknowledge the leaking of design information, as such acknowledgment would potentially validate the information as accurate. In a small number of prior cases,

10868-418: The early stages of launch. If the first stage had used LH2, the volume required would have been more than three times greater, which would have been aerodynamically infeasible at the time. The upper stages also used small solid-propellant ullage motors that helped to separate the stages during the launch, and to ensure that the liquid propellants were in a proper position to be drawn into the pumps. The S-IC

11011-414: The effects of that absorbed energy led to the third mechanism: ablation . The outer casing of the secondary assembly is called the "tamper-pusher". The purpose of a tamper in an implosion bomb is to delay the expansion of the reacting fuel supply (which is very hot dense plasma) until the fuel is fully consumed and the explosion runs to completion. The same tamper material serves also as a pusher in that it

11154-512: The energy of the explosions into a "pancake" area is far more efficient in terms of area-destruction per unit of bomb energy. This also applies to single bombs deliverable by cruise missile or other system, such as a bomber, resulting in most operational warheads in the U.S. program having yields of less than 500 kt (2,100 TJ). In his 1995 book Dark Sun: The Making of the Hydrogen Bomb , author Richard Rhodes describes in detail

11297-675: The entire stack was moved from the Vehicle Assembly Building (VAB) to the launch pad using the Crawler Transporter (CT). Built by the Marion Power Shovel Company (and later used for transporting the smaller and lighter Space Shuttle, as well as the Space Launch System ), the CT ran on four double-tracked treads, each with 57 "shoes". Each shoe weighed 2,000 pounds (910 kg). This transporter

11440-519: The far more powerful Super. The debate covered matters that were alternatively strategic, pragmatic, and moral. In their Report of the General Advisory Committee, Robert Oppenheimer and colleagues concluded that "[t]he extreme danger to mankind inherent in the proposal [to develop thermonuclear weapons] wholly outweighs any military advantage." Despite the objections raised, on 31 January 1950, President Harry S. Truman made

11583-443: The fins, was 33 feet (10 m) in diameter. Fully fueled, the Saturn V weighed 6.5 million pounds (2,900,000 kg) and had a low Earth orbit (LEO) payload capacity originally estimated at 261,000 pounds (118,000 kg), but was designed to send at least 90,000 pounds (41,000 kg) to the Moon. Later upgrades increased that capacity; on the final three Apollo lunar missions, it sent up to 95,901 lb (43,500 kg) to

11726-417: The first 30 seconds of flight. If all three stages were to explode simultaneously on the launch pad, an unlikely event, the Saturn V had a total explosive yield of 543 tons of TNT or 0.543 kilotons (2,271,912,000,000 J or 155,143 lbs of weight loss), which is 0.222 kt for the first stage, 0.263 kt for the second stage and 0.068 kt for the third stage. (See Saturn V Instrument Unit ) Contrary to popular myth ,

11869-456: The first model was constructed. The S-IVB third stage would be used as the second stage for the C-1B, which would serve both to demonstrate proof of concept and feasibility for the C-5, but would also provide flight data critical to the development of the C-5. Rather than undergoing testing for each major component, the C-5 would be tested in an "all-up" fashion, meaning that the first test flight of

12012-457: The first stage ignition sequence started. The center engine ignited first, followed by opposing outboard pairs at 300-millisecond intervals to reduce the structural loads on the rocket. When thrust had been confirmed by the onboard computers, the rocket was "soft-released" in two stages: first, the hold-down arms released the rocket, and second, as the rocket began to accelerate upwards, it was slowed by tapered metal pins pulled through holes for half

12155-436: The fissioning of the final natural uranium tamper, something that could not normally be achieved without the neutron flux provided by the fusion reactions in secondary or tertiary stages. Such designs are suggested to be capable of being scaled up to an arbitrary large yield (with apparently as many fusion stages as desired), potentially to the level of a " doomsday device ." However, usually such weapons were not more than

12298-426: The five J-2 engines. For the first seven crewed Apollo missions, only four ullage motors were used on the S-II, and they were eliminated for the final four launches. About 30 seconds after first stage separation, the interstage ring dropped from the second stage. This was done with an inertially fixed attitude—orientation around its center of gravity —so that the interstage, only 3 feet 3 inches (1 m) from

12441-478: The four outer engines for control. The S-II was 81.6 feet (24.87 m) tall with a diameter of 33 feet (10 m), identical to the S-IC, and thus was the largest cryogenic stage until the launch of the Space Shuttle in 1981. The S-II had a dry mass of about 80,000 pounds (36,000 kg); when fully fueled, it weighed 1,060,000 pounds (480,000 kg). The second stage accelerated the Saturn V through

12584-504: The gap between the Neutron Focus Lens (in the center) and the outer casing near the primary. It separates the primary from the secondary and performs the same function as the previous reflector. There are about six neutron guns (seen here from Sandia National Laboratories ) each protruding through the outer edge of the reflector with one end in each section; all are clamped to the carriage and arranged more or less evenly around

12727-424: The ideas and methods behind the V-2 to American engineers, though he wrote books and articles in popular magazines. This approach changed in 1957, when the Soviets launched Sputnik 1 atop an R-7 ICBM, which could carry a thermonuclear warhead to the U.S. The Army and government began putting more effort towards sending Americans into space before the Soviets. They turned to von Braun's team, who had created

12870-462: The intensities seen in everyday life, such as sunlight striking a surface, is usually imperceptible, but at the extreme intensities found in a thermonuclear bomb the pressure is enormous. For two thermonuclear bombs for which the general size and primary characteristics are well understood, the Ivy Mike test bomb and the modern W-80 cruise missile warhead variant of the W-61 design, the radiation pressure

13013-420: The internal components of the "Ivy Mike" Sausage device, based on information obtained from extensive interviews with the scientists and engineers who assembled it. According to Rhodes, the actual mechanism for the compression of the secondary was a combination of the radiation pressure, foam plasma pressure, and tamper-pusher ablation theories; the radiation from the primary heated the polyethylene foam lining of

13156-504: The interstage was only recently released to the public promoting the 2004 initiation of the Reliable Replacement Warhead (RRW) Program. A graphic includes blurbs describing the potential advantage of a RRW on a part-by-part level, with the interstage blurb saying a new design would replace "toxic, brittle material" and "expensive 'special' material... [that require] unique facilities". The "toxic, brittle material"

13299-528: The last year of the project he was assigned exclusively to the task. However once World War II ended, there was little impetus to devote many resources to the Super , as it was then known. The first atomic bomb test by the Soviet Union in August 1949 came earlier than expected by Americans, and over the next several months there was an intense debate within the U.S. government, military, and scientific communities regarding whether to proceed with development of

13442-415: The layer of fuel is the " spark plug ", a hollow column of fissile material ( Pu or U ) often boosted by deuterium gas. The spark plug, when compressed, can undergo nuclear fission (because of the shape, it is not a critical mass without compression). The tertiary, if one is present, would be set below the secondary and probably be made of the same materials. Separating

13585-427: The lead contractors for construction of the rocket were Boeing , North American Aviation , Douglas Aircraft Company , and IBM . Fifteen flight-capable vehicles were built, not counting three used for ground testing. A total of thirteen missions were launched from Kennedy Space Center , nine of which carried 24 astronauts to the Moon from Apollo 8 (December 1968) to Apollo 17 (December 1972). In September 1945,

13728-432: The low direct plasma pressure they may be of use in delaying the ablation until energy has distributed evenly and a sufficient fraction has reached the secondary's tamper/pusher. Richard Rhodes ' book Dark Sun stated that a 1-inch-thick (25 mm) layer of plastic foam was fixed to the lead liner of the inside of the Ivy Mike steel casing using copper nails. Rhodes quotes several designers of that bomb explaining that

13871-459: The most fuel-efficient trajectory toward its target orbit. If the instrument unit failed, the crew could switch control of the Saturn to the command module's computer, take manual control, or abort the flight. About 90 seconds before the second stage cutoff, the center engine shut down to reduce longitudinal pogo oscillations. At around this time, the LOX flow rate decreased, changing the mix ratio of

14014-500: The noise produced was not able to melt concrete . It took about 12 seconds for the rocket to clear the tower. During this time, it yawed 1.25 degrees away from the tower to ensure adequate clearance despite adverse winds; this yaw, although small, can be seen in launch photos taken from the east or west. At an altitude of 430 feet (130 m) the rocket rolled to the correct flight azimuth and then gradually pitched down until 38 seconds after second stage ignition. This pitch program

14157-503: The outboard J-2 engines, would fall cleanly without hitting them, as the interstage could have potentially damaged two of the J-2 engines if it was attached to the S-IC. Shortly after interstage separation the Launch Escape System was also jettisoned. About 38 seconds after the second stage ignition, the Saturn V switched from a preprogrammed trajectory to a "closed loop" or Iterative Guidance Mode. The instrument unit now computed in real time

14300-424: The outer radiation case, with the components coming to a thermal equilibrium , and the effects of that thermal energy are then analyzed. The energy is mostly deposited within about one X-ray optical thickness of the tamper/pusher outer surface, and the temperature of that layer can then be calculated. The velocity at which the surface then expands outwards is calculated and, from a basic Newtonian momentum balance,

14443-438: The plastic foam layer inside the outer case is to delay ablation and thus recoil of the outer case: if the foam were not there, metal would ablate from the inside of the outer case with a large impulse, causing the casing to recoil outwards rapidly. The purpose of the casing is to contain the explosion for as long as possible, allowing as much X-ray ablation of the metallic surface of the secondary stage as possible, so it compresses

14586-551: The powerful F-1 and J-2 rocket engines ; during testing at Stennis Space Center, the force developed by the engines shattered the windows of nearby houses. Designers decided early on to attempt to use as much technology from the Saturn I program as possible for the Saturn V. Consequently, the S-IVB -500 third stage of the Saturn V was based on the S-IVB-200 second stage of the Saturn IB . The instrument unit that controlled

14729-413: The pressure produced by such a plasma would only be a small multiplier of the basic photon pressure within the radiation case, and also that the known foam materials intrinsically have a very low absorption efficiency of the gamma ray and X-ray radiation from the primary. Most of the energy produced would be absorbed by either the walls of the radiation case or the tamper around the secondary. Analyzing

14872-519: The primary and secondary assemblies placed within an enclosure called a radiation case, which confines the X-ray energy and resists its outward pressure. The distance separating the two assemblies ensures that debris fragments from the fission primary (which move much more slowly than X-ray photons ) cannot disassemble the secondary before the fusion explosion runs to completion. The secondary fusion stage—consisting of outer pusher/ tamper , fusion fuel filler and central plutonium spark plug—is imploded by

15015-442: The primary and secondary at either end. It does not reflect like a mirror; instead, it gets heated to a high temperature by the X-ray flux from the primary, then it emits more evenly spread X-rays that travel to the secondary, causing what is known as radiation implosion . In Ivy Mike , gold was used as a coating over the uranium to enhance the blackbody effect. Next comes the "Reflector/Neutron Gun Carriage". The reflector seals

15158-425: The primary would be used to compress and ignite the secondary fusion stage, resulting in a fusion explosion many times more powerful than the fission explosion alone. This chain of compression could conceivably be continued with an arbitrary number of tertiary fusion stages, each igniting more fusion fuel in the next stage although this is debated. Finally, efficient bombs (but not so-called neutron bombs ) end with

15301-448: The pure element or in modern weapons lithium deuteride . For this reason, thermonuclear weapons are often colloquially called hydrogen bombs or H-bombs . A fusion explosion begins with the detonation of the fission primary stage. Its temperature soars past 100 million kelvin , causing it to glow intensely with thermal ("soft") X-rays . These X-rays flood the void (the "radiation channel" often filled with polystyrene foam ) between

15444-421: The record for the largest payload capacity to low Earth orbit, 311,152 lb (141,136 kg), which included unburned propellant needed to send the Apollo command and service module and Lunar Module to the Moon. The largest production model of the Saturn family of rockets , the Saturn V was designed under the direction of Wernher von Braun at the Marshall Space Flight Center in Huntsville, Alabama ;

15587-418: The rest of the tamper-pusher to recoil inwards with tremendous force, crushing the fusion fuel and the spark plug. The tamper-pusher is built robustly enough to insulate the fusion fuel from the extreme heat outside; otherwise, the compression would be spoiled. Rough calculations for the basic ablation effect are relatively simple: the energy from the primary is distributed evenly onto all of the surfaces within

15730-511: The rocket rapidly lost mass, total acceleration including gravity increased to nearly 4  g at T+135 seconds. At this point, the inboard (center) engine was shut down to prevent acceleration from increasing beyond 4  g . When oxidizer or fuel depletion was sensed in the suction assemblies, the remaining four outboard engines were shut down. First stage separation occurred a little less than one second after this to allow for F-1 thrust tail-off. Eight small solid fuel separation motors backed

15873-468: The rocket would include complete versions of all three stages. By testing all components at once, far fewer test flights would be required before a crewed launch. The C-5 was confirmed as NASA's choice for the Apollo program in early 1962, and was named the Saturn ;V. The C-1 became the Saturn I and C-1B became Saturn IB. Von Braun headed a team at the MSFC to build a vehicle capable of launching

16016-400: The same height and mass and contained the same electrical connections as the actual stages. NASA stacked (assembled) the Saturn V on a Mobile Launcher , which consisted of a Launch Umbilical Tower with nine swing arms (including the crew access arm), a "hammerhead" crane, and a water suppression system which was activated prior to engine ignition during a launch. After assembly was completed,

16159-450: The secondary efficiently, maximizing the fusion yield. Plastic foam has a low density, so causes a smaller impulse when it ablates than metal does. Possible variations to the weapon design have been proposed: Most bombs do not apparently have tertiary "stages"—that is, third compression stage(s), which are additional fusion stages compressed by a previous fusion stage. The fissioning of the last blanket of uranium, which provides about half

16302-422: The secondary from the primary is the interstage . The fissioning primary produces four types of energy: 1) expanding hot gases from high explosive charges that implode the primary; 2) superheated plasma that was originally the bomb's fissile material and its tamper; 3) the electromagnetic radiation ; and 4) the neutrons from the primary's nuclear detonation. The interstage is responsible for accurately modulating

16445-594: The secondary stages by radiation implosion. Because of these difficulties, in 1955 Prime Minister Anthony Eden agreed to a secret plan, whereby if the Aldermaston scientists failed or were greatly delayed in developing the fusion bomb, it would be replaced by an extremely large fission bomb. In 1957 the Operation Grapple tests were carried out. The first test, Green Granite, was a prototype fusion bomb that failed to produce equivalent yields compared to

16588-527: The shaped explosive charges attached to the outer surfaces of the rocket to detonate. These would make cuts in fuel and oxidizer tanks to disperse the fuel quickly and to minimize mixing. The pause between these two actions would give time for the crew to escape via the Launch Escape Tower or (in the later stages of the flight) the propulsion system of the Service module. A third command, "safe",

16731-418: The spark plug to around 300 million kelvin, igniting fusion reactions between fusion fuel nuclei. In modern weapons fueled by lithium deuteride, the fissioning plutonium spark plug also emits free neutrons that collide with lithium nuclei and supply the tritium component of the thermonuclear fuel. The secondary's relatively massive tamper (which resists outward expansion as the explosion proceeds) also serves as

16874-407: The tamper and radiation case is the main contribution to the total yield and is the dominant process that produces radioactive fission product fallout . Before Ivy Mike, Operation Greenhouse in 1951 was the first American nuclear test series to test principles that led to the development of thermonuclear weapons. Sufficient fission was achieved to boost the associated fusion device, and enough

17017-485: The third stage ignited. Solid fuel retro-rockets mounted on the interstage at the top of the S-II fired to back it away from the S-IVB. The S-II impacted about 2,600 miles (4,200 km) from the launch site. Thermonuclear weapon A thermonuclear weapon , fusion weapon or hydrogen bomb ( H bomb ) is a second-generation nuclear weapon design . Its greater sophistication affords it vastly greater destructive power than first-generation nuclear bombs ,

17160-458: The top of the LOX tank and bottom of the LH2 tank. It consisted of two aluminum sheets separated by a honeycomb structure made of phenolic resin . This bulkhead had to be able to insulate against the 126 °F (70 °C) temperature difference between the two tanks. The use of a common bulkhead saved 7,900 pounds (3.6 t) by both eliminating one bulkhead and reducing the stage's length. Like

17303-404: The transfer of energy from the primary to the secondary. It must direct the hot gases, plasma, electromagnetic radiation and neutrons toward the right place at the right time. Less than optimal interstage designs have resulted in the secondary failing to work entirely on multiple shots, known as a " fissile fizzle ". The Castle Koon shot of Operation Castle is a good example; a small flaw allowed

17446-465: The two launch pads). From 1964 until 1973, $ 6.417 billion (equivalent to $ 40.9 billion in 2023) was appropriated for the Research and Development and flights of the Saturn V, with the maximum being in 1966 with $ 1.2 billion (equivalent to $ 8.61 billion in 2023). That same year, NASA received its largest total budget of $ 4.5 billion, about 0.5 percent of the gross domestic product (GDP) of

17589-439: The two propellants and ensuring that there would be as little propellant as possible left in the tanks at the end of second stage flight. This was done at a predetermined delta-v . Five level sensors in the bottom of each S-II propellant tank were armed during S-II flight, allowing any two to trigger S-II cutoff and staging when they were uncovered. One second after the second stage cut off it separated and several seconds later

17732-422: The upper atmosphere with 1,100,000 pounds-force (4,900 kN) of thrust in a vacuum. When loaded with fuel, more than 90 percent of the mass of the stage was propellant; however, the ultra-lightweight design had led to two failures in structural testing. Instead of having an intertank structure to separate the two fuel tanks as was done in the S-IC, the S-II used a common bulkhead that was constructed from both

17875-633: The vehicle (equivalent to $ 1.18 billion–$ 1.2 billion in 2023). The Saturn V carried all Apollo lunar missions, which were launched from Launch Complex 39 at the John F. Kennedy Space Center in Florida . After the rocket cleared the launch tower, flight control transferred to Mission Control at the Johnson Space Center in Houston, Texas . An average mission used the rocket for

18018-412: The velocity at which the rest of the tamper implodes inwards. Applying the more detailed form of those calculations to the Ivy Mike device yields vaporized pusher gas expansion velocity of 290 kilometres per second (29 cm/μs) and an implosion velocity of perhaps 400 km/s (40 cm/μs) if + 3 ⁄ 4 of the total tamper/pusher mass is ablated off, the most energy efficient proportion. For

18161-404: The weapon (with the foam) would be as follows: This would complete the fission-fusion-fission sequence. Fusion, unlike fission, is relatively "clean"—it releases energy but no harmful radioactive products or large amounts of nuclear fallout . The fission reactions though, especially the last fission reactions, release a tremendous amount of fission products and fallout. If the last fission stage

18304-500: The yield in large bombs, does not count as a "stage" in this terminology. The U.S. tested three-stage bombs in several explosions during Operation Redwing but is thought to have fielded only one such tertiary model, i.e., a bomb in which a fission stage, followed by a fusion stage, finally compresses yet another fusion stage. This U.S. design was the heavy but highly efficient (i.e., nuclear weapon yield per unit bomb weight) 25 Mt (100 PJ) B41 nuclear bomb . The Soviet Union

18447-471: Was also designed with high mass efficiency, though not quite as aggressively as the S-II. The S-IVB had a dry mass of about 23,000 pounds (10,000 kg) and, when fully fueled, weighed about 262,000 pounds (119,000 kg). The S-IVB was the only rocket stage of the Saturn V small enough to be transported by the cargo plane Aero Spacelines Pregnant Guppy . For lunar missions it was fired twice: first for Earth orbit insertion after second stage cutoff, and

18590-526: Was also required to keep the rocket level as it traveled the 3 miles (4.8 km) to the launch site, especially at the 3 percent grade encountered at the launch pad. The CT also carried the Mobile Service Structure (MSS), which allowed technicians access to the rocket until eight hours before launch, when it was moved to the "halfway" point on the Crawlerway (the junction between the VAB and

18733-573: Was built by the Boeing Company at the Michoud Assembly Facility , New Orleans , where the Space Shuttle external tanks would later be built by Lockheed Martin . Most of its mass at launch was propellant: RP-1 fuel with liquid oxygen as the oxidizer . The stage was 138 feet (42 m) tall and 33 feet (10 m) in diameter. It provided 7,750,000 lbf (34,500 kN) of thrust at sea level. The S-IC stage had

18876-486: Was calculated to be 73 × 10 ^   bar (7.3  TPa ) for the Ivy Mike design and 1,400 × 10 ^   bar (140  TPa ) for the W-80. Foam plasma pressure is the concept that Chuck Hansen introduced during the Progressive case, based on research that located declassified documents listing special foams as liner components within the radiation case of thermonuclear weapons. The sequence of firing

19019-567: Was carried by the Aero Spacelines Pregnant Guppy and Super Guppy , but could also have been carried by barge if warranted. Upon arrival at the Vertical Assembly Building, each stage was inspected in a horizontal position before being oriented vertically. NASA also constructed large spool-shaped structures that could be used in place of stages if a particular stage was delayed. These spools had

19162-451: Was carried out by the United States in 1952, and the concept has since been employed by most of the world's nuclear powers in the design of their weapons. Modern fusion weapons essentially consist of two main components: a nuclear fission primary stage (fueled by U or Pu ) and a separate nuclear fusion secondary stage containing thermonuclear fuel: heavy isotopes of hydrogen ( deuterium and tritium ) as

19305-415: Was cut off by the United States at one point due to concerns about Soviet espionage. Full cooperation was not reestablished until an agreement governing the handling of secret information and other issues was signed. However, the British were allowed to observe the U.S. Castle tests and used sampling aircraft in the mushroom clouds , providing them with clear, direct evidence of the compression produced in

19448-604: Was discovered and developed by Sakharov and Yakov Zel'dovich in early 1954. Sakharov's "Third Idea", as the Teller–Ulam design was known in the USSR, was tested in the shot " RDS-37 " in November 1955 with a yield of 1.6 Mt (6.7 PJ). The Soviets demonstrated the power of the staging concept in October 1961, when they detonated the massive and unwieldy Tsar Bomba. It was the largest nuclear weapon developed and tested by any country. In 1954 work began at Aldermaston to develop

19591-509: Was impractical for a deployable weapon, and the next advance was to use a solid lithium deuteride fusion fuel instead. In 1954 this was tested in the " Castle Bravo " shot (the device was code-named Shrimp ), which had a yield of 15  Mt (63  PJ ) (2.5 times expected) and is the largest U.S. bomb ever tested. Efforts shifted towards developing miniaturized Teller–Ulam weapons that could fit into intercontinental ballistic missiles and submarine-launched ballistic missiles . By 1960, with

19734-463: Was learned to achieve a full-scale device within a year. The design of all modern thermonuclear weapons in the United States is known as the Teller–Ulam configuration for its two chief contributors, Edward Teller and Stanisław Ulam , who developed it in 1951 for the United States, with certain concepts developed with the contribution of physicist John von Neumann . Similar devices were developed by

19877-400: Was set according to the prevailing winds during the launch month. The four outboard engines also tilted toward the outside so that in the event of a premature outboard engine shutdown the remaining engines would thrust through the rocket's center of mass . The Saturn V reached 400 feet per second (120 m/s) at over 1 mile (1,600 m) in altitude. Much of the early portion of the flight

20020-451: Was spent gaining altitude, with the required velocity coming later. The Saturn V broke the sound barrier at just over 1 minute at an altitude of between 3.45 and 4.6 miles (5.55 and 7.40 km). At this point, shock collars, or condensation clouds, would form around the bottom of the command module and around the top of the second stage. At about 80 seconds, the rocket experienced maximum dynamic pressure (max q). The dynamic pressure on

20163-483: Was then assigned as the special assistant to the director of MSFC in May 1968 and subsequently retired from NASA on January 1, 1969. On July 16, 1969, the Saturn V launched Apollo 11 , putting the first men on the Moon. The size and payload capacity of the Saturn V dwarfed those of all other previous rockets successfully flown at that time. With the Apollo spacecraft on top, it stood 363 feet (111 m) tall, and, ignoring

20306-427: Was turned off about 26 seconds earlier than the outboard engines to limit acceleration. During launch, the S-IC fired its engines for 168 seconds (ignition occurred about 8.9 seconds before liftoff) and at engine cutoff, the vehicle was at an altitude of about 42 miles (67 km), was downrange about 58 miles (93 km), and was moving around 7,500 feet per second (2,300 m/s). While not put into production,

20449-453: Was used after the S-IVB stage reached orbit to irreversibly deactivate the self-destruct system. The system was also held inactive as long as the rocket was still on the launch pad. The first stage burned for about 2 minutes and 41 seconds, lifting the rocket to an altitude of 42 miles (68 km) and a speed of 6,164 miles per hour (2,756 m/s) and burning 4,700,000 pounds (2,100,000 kg) of propellant. At 8.9 seconds before launch,

#293706