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Friday, May 31, 2019

Peter Higgs

From Wikipedia, the free encyclopedia

Peter Higgs

Nobel Prize 24 2013.jpg
Nobel laureate Peter Higgs at a press conference, Stockholm, December 2013
Born
Peter Ware Higgs

29 May 1929
Newcastle upon Tyne, England, UK
ResidenceEdinburgh, Scotland, UK
NationalityBritish
Alma materKing's College London (BSc, MSc, PhD)
Known forHiggs boson
Higgs field
Higgs mechanism
Symmetry breaking
Spouse(s)
Jody Williamson (m. 1963)
Children2
Awards
Scientific career
FieldsTheoretical physics
InstitutionsUniversity of Edinburgh Imperial College London
University College London
King's College London
ThesisSome problems in the theory of molecular vibrations (1955)
Doctoral advisorCharles Coulson Christopher Longuet-Higgins
Doctoral students
Websitewww.ph.ed.ac.uk/higgs
Signature
Peter Higgs.jpg

Peter Ware Higgs CH FRS FRSE FInstP (born 29 May 1929) is a British theoretical physicist, emeritus professor in the University of Edinburgh, and Nobel Prize laureate for his work on the mass of subatomic particles.

In the 1960s, Higgs proposed that broken symmetry in electroweak theory could explain the origin of mass of elementary particles in general and of the W and Z bosons in particular. This so-called Higgs mechanism, which was proposed by several physicists besides Higgs at about the same time, predicts the existence of a new particle, the Higgs boson, the detection of which became one of the great goals of physics. On 4 July 2012, CERN announced the discovery of the boson at the Large Hadron Collider. The Higgs mechanism is generally accepted as an important ingredient in the Standard Model of particle physics, without which certain particles would have no mass.

Higgs has been honoured with a number of awards in recognition of his work, including the 1981 Hughes Medal from the Royal Society; the 1984 Rutherford Medal from the Institute of Physics; the 1997 Dirac Medal and Prize for outstanding contributions to theoretical physics from the Institute of Physics; the 1997 High Energy and Particle Physics Prize by the European Physical Society; the 2004 Wolf Prize in Physics; the 2009 Oskar Klein Memorial Lecture medal from the Royal Swedish Academy of Sciences; the 2010 American Physical Society J. J. Sakurai Prize for Theoretical Particle Physics; and a unique Higgs Medal from the Royal Society of Edinburgh in 2012. The discovery of the Higgs boson prompted fellow physicist Stephen Hawking to note that he thought that Higgs should receive the Nobel Prize in Physics for his work, which he finally did, shared with François Englert in 2013. Higgs was appointed to the Order of the Companions of Honour in the 2013 New Year Honours and in 2015 the Royal Society awarded him the Copley Medal, the world's oldest scientific prize.

Early life and education

Higgs was born in the Elswick district of Newcastle upon Tyne, England, to Thomas Ware Higgs (1898-1962) and his wife Gertrude Maude née Coghill (1895-1969). His father worked as a sound engineer for the BBC, and as a result of childhood asthma, together with the family moving around because of his father's job and later World War II, Higgs missed some early schooling and was taught at home. When his father relocated to Bedford, Higgs stayed behind with his mother in Bristol, and was largely raised there. He attended Cotham Grammar School in Bristol from 1941–46, where he was inspired by the work of one of the school's alumni, Paul Dirac, a founder of the field of quantum mechanics.

In 1946, at the age of 17, Higgs moved to City of London School, where he specialised in mathematics, then in 1947 to King's College London where he graduated with a first class honours degree in Physics in 1950 and achieved a master's degree in 1952. He was awarded an 1851 Research Fellowship from the Royal Commission for the Exhibition of 1851, and performed his doctoral research in molecular physics under the supervision of Charles Coulson and Christopher Longuet-Higgins. He was awarded a PhD degree in 1954 with a thesis entitled Some problems in the theory of molecular vibrations.

Career and research

After finishing his doctorate, Higgs was appointed a Senior Research Fellow at the University of Edinburgh (1954–56). He then held various posts at Imperial College London, and University College London (where he also became a temporary lecturer in Mathematics). He returned to the University of Edinburgh in 1960 to take up the post of Lecturer at the Tait Institute of Mathematical Physics, allowing him to settle in the city he had enjoyed while hitchhiking to the Western Highlands as a student in 1949. He was promoted to Reader, became a Fellow of the Royal Society of Edinburgh (FRSE) in 1974 and was promoted to a Personal Chair of Theoretical Physics in 1980. He retired in 1996 and became Emeritus professor at the University of Edinburgh.

Higgs was elected Fellow of the Royal Society (FRS) in 1983 and Fellow of the Institute of Physics (FInstP) in 1991. He was awarded the Rutherford Medal and Prize in 1984. He received an honorary degree from the University of Bristol in 1997. In 2008 he received an Honorary Fellowship from Swansea University for his work in particle physics.

At Edinburgh Higgs first became interested in mass, developing the idea that particles – massless when the universe began – acquired mass a fraction of a second later as a result of interacting with a theoretical field (which became known as the Higgs field). Higgs postulated that this field permeates space, giving mass to all elementary subatomic particles that interact with it.

The Higgs mechanism postulates the existence of the Higgs field which confers mass on quarks and leptons. However this causes only a tiny portion of the masses of other subatomic particles, such as protons and neutrons. In these, gluons that bind quarks together confer most of the particle mass.

The original basis of Higgs' work came from the Japanese-born theorist and Nobel Prize laureate Yoichiro Nambu from the University of Chicago. Professor Nambu had proposed a theory known as spontaneous symmetry breaking based on what was known to happen in superconductivity in condensed matter; however, the theory predicted massless particles (the Goldstone's theorem), a clearly incorrect prediction.

Higgs is reported to have developed the basic fundamentals of his theory after returning to his Edinburgh New Town apartment from a failed weekend camping trip to the Highlands. He stated that there was no "eureka moment" in the development of the theory. He wrote a short paper exploiting a loophole in Goldstone's theorem (massless Goldstone particles need not occur when local symmetry is spontaneously broken in a relativistic theory) and published it in Physics Letters, a European physics journal edited at CERN, in Switzerland, in 1964.

Higgs wrote a second paper describing a theoretical model (now called the Higgs mechanism), but the paper was rejected (the editors of Physics Letters judged it "of no obvious relevance to physics"). Higgs wrote an extra paragraph and sent his paper to Physical Review Letters, another leading physics journal, which published it later in 1964. This paper predicted a new massive spin-zero boson (now known as the Higgs boson). Other physicists, Robert Brout and François Englert and Gerald Guralnik, C. R. Hagen and Tom Kibble had reached similar conclusions about the same time. In the published version Higgs quotes Brout and Englert and the third paper quotes the previous ones. The three papers written on this boson discovery by Higgs, Guralnik, Hagen, Kibble, Brout, and Englert were each recognized as milestone papers by Physical Review Letters 50th anniversary celebration. While each of these famous papers took similar approaches, the contributions and differences between the 1964 PRL symmetry breaking papers are noteworthy. The mechanism had been proposed in 1962 by Philip Anderson although he did not include a crucial relativistic model.

On 4 July 2012, CERN announced the ATLAS and Compact Muon Solenoid (CMS) experiments had seen strong indications for the presence of a new particle, which could be the Higgs boson, in the mass region around 126 gigaelectronvolts (GeV). Speaking at the seminar in Geneva, Higgs commented "It's really an incredible thing that it's happened in my lifetime." Ironically, this probable confirmation of the Higgs boson was made at the same place where the editor of Physics Letters rejected Higgs' paper.

Awards and honours

Higgs has received numerous accolades including:

Civic Awards

Higgs was the recipient of the Edinburgh Award for 2011. He is the fifth person to receive the Award, which was established in 2007 by the City of Edinburgh Council to honour an outstanding individual who has made a positive impact on the city and gained national and international recognition for Edinburgh.

Higgs was presented with an engraved loving cup by the Rt Hon George Grubb, Lord Provost of Edinburgh, in a ceremony held at the City Chambers on Friday 24 February 2012. The event also marked the unveiling of his handprints in the City Chambers quadrangle, where they had been engraved in Caithness stone alongside those of previous Edinburgh Award recipients.

Prof Higgs was awarded with the Freedom of the City of Bristol in July 2013. In April 2014, he was also awarded the Freedom of the City of Newcastle upon Tyne. He was also honoured with a brass plaque installed on the Newcastle Quayside as part of the Newcastle Gateshead Initiative Local Heroes Walk of Fame.

Higgs Centre for Theoretical Physics

On 6 July 2012, Edinburgh University announced a new centre named after Professor Higgs to support future research in theoretical physics. The Higgs Centre for Theoretical Physics brings together scientists from around the world to seek "a deeper understanding of how the universe works". The centre is currently based within the James Clerk Maxwell Building, home of the University's School of Physics and Astronomy and the iGEM 2015 team (ClassAfiED). The university has also established a chair of theoretical physics in the name of Peter Higgs.

Nobel Prize in Physics

On 8 October 2013, it was announced that Peter Higgs and François Englert would share the 2013 Nobel Prize in Physics "for the theoretical discovery of a mechanism that contributes to our understanding of the origin of mass of subatomic particles", and which recently was confirmed through the discovery of the predicted fundamental particle, by the ATLAS and CMS experiments at CERN’s Large Hadron Collider". Higgs admits he had gone out to avoid the media attention so he was informed he had been awarded the prize by an ex-neighbour on his way home, since he did not have a mobile phone.

Companion of Honour

Higgs turned down a knighthood in 1999, but in 2012 he accepted membership of The Order of the Companion of Honour. A Guardian interview with the physicist later stated that he only accepted the order because he was wrongly assured that the award was the gift of the Queen alone. He also expressed cynicism towards the honours system, and the way the system "is used for political purposes by the government in power". The order confers no title or precedence, but recipients of the order are entitled to use the post-nominal letters CH. In the same interview he also stated that when people ask what the CH after his name stands for, he replies "it means I'm an honorary Swiss." He received the order from the Queen at an investiture at Holyrood House on 1 July 2014.

Honorary Degrees

Peter Higgs portrait by Lucinda Mackay hanging at James Clerk Maxwell Foundation

Higgs has been awarded honorary degrees from the following institutions:
A portrait of Higgs was painted by Ken Currie in 2008. Commissioned by the University of Edinburgh, it was unveiled on 3 April 2009 and hangs in the entrance of the James Clerk Maxwell Building of the School of Physics and Astronomy and the School of Mathematics. A large portrait by Lucinda Mackay is in the collection of the Scottish National Portrait Gallery in Edinburgh. Another portrait of Higgs by the same artist hangs in the birthplace of James Clerk Maxwell in Edinburgh, Higgs is the Honorary Patron of the James Clerk Maxwell Foundation. A portrait by Victoria Crowe was commissioned by the Royal Society of Edinburgh and unveiled in 2013.

Personal life and political views

Higgs married Jody Williamson, a fellow activist with the Campaign for Nuclear Disarmament (CND) in 1963. Their first son was born in August 1965. Higgs's family includes two sons: Chris, a computer scientist, and Jonny, a jazz musician. He has two grandchildren. The entire family lives in Edinburgh.

Higgs was an activist in the CND while in London and later in Edinburgh, but resigned his membership when the group extended its remit from campaigning against nuclear weapons to campaigning against nuclear power too. He was a Greenpeace member until the group opposed genetically modified organisms.

Higgs was awarded the 2004 Wolf Prize in Physics (sharing it with Brout and Englert), but he refused to fly to Jerusalem to receive the award because it was a state occasion attended by the then president of Israel, Moshe Katsav, and Higgs is opposed to Israel's actions in Palestine.

Higgs was actively involved in the Edinburgh University branch of the Association of University Teachers, through which he agitated for greater staff involvement in the management of the physics department.

Higgs is an atheist. He has described Richard Dawkins as having adopted a "fundamentalist" view of non-atheists. Higgs expressed later that he was displeased that the Higgs particle is nicknamed the "God particle", as he believes the term "might offend people who are religious". Usually this nickname for the Higgs boson is attributed to Leon Lederman, the author of the book The God Particle: If the Universe Is the Answer, What Is the Question?, but the name is the result of the suggestion of Lederman's publisher: Lederman had originally intended to refer to it as the "goddamn particle".

Saturn (rocket family)

From Wikipedia, the free encyclopedia

The SA-9 (Saturn I Block II), the eighth Saturn I flight, lifted off on February 16, 1965. This was the first Saturn with an operational payload, the Pegasus I meteoroid detection satellite.
 
The Saturn family of American rocket boosters was developed by a team of mostly German rocket scientists led by Wernher von Braun to launch heavy payloads to Earth orbit and beyond. Originally proposed as a military satellite launcher, they were adopted as the launch vehicles for the Apollo moon program. Three versions were built and flown: Saturn I, Saturn IB, and Saturn V

The Saturn name was proposed by von Braun in October 1958 as a logical successor to the Jupiter series as well as the Roman god's powerful position.

In 1963, president John F. Kennedy identified the Saturn I SA-5 launch as being the point where US lift capability would surpass the Soviets, after having been behind since Sputnik. He last mentioned this in a speech given at Brooks AFB in San Antonio on the day before he was assassinated. 

To date, the Saturn V is the only launch vehicle to transport human beings beyond low Earth orbit. A total of 24 humans were flown to the Moon in the four years spanning December 1968 through December 1972. No Saturn rocket failed catastrophically in flight.

Von Braun with the F-1 engines of the Saturn V first stage at the U.S. Space and Rocket Center

History

Early development

A Saturn I (SA-1)
 
A Saturn IB (AS-202)
 
Roll out of Apollo 11's Saturn V on launch pad
 
In the early 1950s, the US Navy and US Army actively developed long-range missiles with the help of German rocket engineers who were involved in developing the successful V-2 during the second World War. These missiles included the Navy's Viking, and the Army's Corporal, Jupiter and Redstone. Meanwhile, the US Air Force developed its Atlas and Titan missiles, relying more on American engineers. 

Infighting among the various branches was constant, with the United States Department of Defense (DoD) deciding which projects to fund for development. On November 26, 1956, Defense Secretary Charles E. Wilson issued a memorandum stripping the Army of offensive missiles with a range of 200 miles (320 km) or greater, and turning their Jupiter missiles over to the Air Force. From that point on, the Air Force would be the primary missile developer, especially for dual-use missiles that could also be used as space launch vehicles.

In late 1956, the Department of Defense released a requirement for a heavy-lift vehicle to orbit a new class of communications and "other" satellites (the spy satellite program was top secret). The requirements, drawn up by the then-unofficial Advanced Research Projects Agency (ARPA), called for a vehicle capable of putting 9,000 to 18,000 kilograms into orbit, or accelerating 2,700 to 5,400 kg to escape velocity.

Since the Wilson memorandum covered only weapons, not space vehicles, the Army Ballistic Missile Agency (ABMA) saw this as a way to continue development of their own large-rocket projects. In April 1957, von Braun directed Heinz-Hermann Koelle, chief of the Future Projects design branch, to study dedicated launch vehicle designs that could be built as quickly as possible. Koelle evaluated a variety of designs for missile-derived launchers that could place a maximum of about 1,400 kg in orbit, but might be expanded to as much as 4,500 kg with new high-energy upper stages. In any event, these upper stages would not be available until 1961 or 62 at the earliest, and the launchers would still not meet the DoD requirements for heavy loads.

In order to fill the projected need for loads of 10,000 kg or greater, the ABMA team calculated that a booster (first stage) with a thrust of about 1,500,000 lbf (6,700 kN) thrust would be needed, far greater than any existing or planned missile. For this role they proposed using a number of existing missiles clustered together to produce a single larger booster; using existing designs they looked at combining tankage from one Jupiter as a central core, with eight Redstone diameter tanks attached to it. This relatively cheap configuration allowed existing fabrication and design facilities to be used to produce this "quick and dirty" design.

F-1 rocket engine on display at Kennedy Space Center
 
Two approaches to building the Super-Jupiter were considered; the first used multiple engines to reach the 1,500,000 lbf (6,700 kN) mark, the second used a single much larger engine. Both approaches had their own advantages and disadvantages. Building a smaller engine for clustered use would be a relatively low-risk path from existing systems, but required duplication of systems and made the possibility of one engine failure much higher (adding engines generally reduces reliability, as per Lusser's law). A single larger engine would be more reliable, and would offer higher performance because it eliminated duplication of "dead weight" like fuel plumbing and hydraulics for steering the engines. On the downside, an engine of this size had never been built before and development would be expensive and risky. The Air Force had recently expressed an interest in such an engine, which would develop into the famed F-1, but at the time they were aiming for 1,000,000 lbf (4,400 kN) and the engines would not be ready until the mid-1960s. The engine-cluster appeared to be the only way to meet the requirements on time and budget.

Super-Jupiter was the first-stage booster only; to place payloads in orbit, additional upper stages would be needed. ABMA proposed using either the Titan or Atlas as a second stage, optionally with the new Centaur upper-stage. The Centaur had been proposed by General Dynamics (Astronautics Corp.) as an upper stage for the Atlas (also their design) in order to quickly produce a launcher capable of placing loads up to 8,500 lb (3,900 kg) into low Earth orbit. The Centaur was based on the same "balloon tank" concept as the Atlas, and built on the same jigs at the same 120-inch (3,000 mm) diameter. As the Titan was deliberately built at the same size as well, this meant the Centaur could be used with either missile. Given that the Atlas was the higher priority of the two ICBM projects and its production was fully accounted for, ABMA focussed on "backup" design, Titan, although they proposed extending it in length in order to carry additional fuel.

In December 1957, ABMA delivered Proposal: A National Integrated Missile and Space Vehicle Development Program to the DoD, detailing their clustered approach. They proposed a booster consisting of a Jupiter missile airframe surrounded by eight Redstones acting as tankage, a thrust plate at the bottom, and four Rocketdyne E-1 engines of 360 to 380,000 lbf (1,700 kN). The ABMA team also left the design open to future expansion with a single 1,500,000 lbf (6,700 kN) engine, which would require relatively minor changes to the design. The upper stage was the lengthened Titan, with the Centaur on top. The result was a very tall and skinny rocket, quite different from the Saturn that eventually emerged. 

Specific uses were forecast for each of the military services, including navigation satellites for the Navy; reconnaissance, communications, and meteorological satellites for the Army and Air Force; support for Air Force manned missions; and surface-to-surface logistics supply for the Army at distances up to 6400 km. Development and testing of the lower stage stack was projected to be completed by 1963, about the same time that the Centaur should become available for testing in combination. The total development cost of $850 million during the years 1958–1963 covered 30 research and development flights, some carrying manned and unmanned space payloads.

Sputnik stuns the world

While the Super-Juno program was being drawn up, preparations were underway for the first satellite launch as the US contribution to the International Geophysical Year in 1957. For complex political reasons, the program had been given to the US Navy under Project Vanguard. The Vanguard launcher consisted of a Viking lower stage combined with new uppers adapted from sounding rockets. ABMA provided valuable support on Viking and Vanguard, both with their first-hand knowledge of the V-2, as well as developing its guidance system. The first three Vanguard suborbital test flights had gone off without a hitch, starting in December 1956, and a launch was planned for late 1957.

On October 4, 1957, the Soviet Union unexpectedly launched Sputnik I. Although there had been some idea that the Soviets were working towards this goal, even in public, no one considered it to be very serious. When asked about the possibility in a November 1954 press conference, Defense Secretary Wilson replied "I wouldn't care if they did." The public did not see it the same way, however, and the event was a major public relations disaster for the US. Vanguard was planned to launch shortly after Sputnik, but a series of delays pushed this into December, when the rocket exploded in spectacular fashion. The press was harsh, referring to the project as "Kaputnik" or "Project Rearguard". As Time Magazine noted at the time:
But in the midst of the cold war, Vanguard's cool scientific goal proved to be disastrously modest: the Russians got there first. The post-Sputnik White House explanation that the U.S. was not in a satellite "race" with Russia was not just an after-the-fact alibi. Said Dr. Hagen ten months ago: "We are not attempting in any way to race with the Russians." But in the eyes of the world, the U.S. was in a satellite race whether it wanted to be or not, and because of the Administration's costly failure of imagination, Project Vanguard shuffled along when it should have been running. It was still shuffling when Sputnik's beeps told the world that Russia's satellite program, not the U.S.'s, was the vanguard.
von Braun responded to Sputnik I's launch by claiming he could have a satellite in orbit within 90 days of being given a go-ahead. His plan was to combine the existing Jupiter C rocket (confusingly, a Redstone adaptation, not a Jupiter) with the solid-fuel engines from the Vanguard, producing the Juno I. There was no immediate response while everyone waited for Vanguard to launch, but the continued delays in Vanguard and the November launch of Sputnik II resulted in the go-ahead being given that month. von Braun kept his promise with the successful launch of Explorer I on January 31, 1958. Vanguard was finally successful on March 17, 1958.

ARPA selects Juno

Concerned that the Soviets continued to surprise the U.S. with technologies that seemed beyond their capabilities, the DoD studied the problem and concluded that it was primarily bureaucratic. As all of the branches of the military had their own research and development programs, there was considerable duplication and inter-service fighting for resources. Making matters worse, the DoD imposed its own Byzantine procurement and contracting rules, adding considerable overhead. To address these concerns, the DoD initiated the formation of a new research and development group focused on launch vehicles and given wide discretionary powers that cut across traditional Army/Navy/Air Force lines. The group was given the job of catching up to the Soviets in space technology as quickly as possible, using whatever technology it could, regardless of the origin. Formalized as Advanced Research Projects Agency (ARPA) on February 7, 1958, the group examined the DoD launcher requirements and compared the various approaches that were currently available. 

At the same time that ABMA was drawing up the Super-Juno proposal, the Air Force was in the midst of working on their Titan C concept. The Air Force had gained valuable experience working with liquid hydrogen on the Lockheed CL-400 Suntan spy plane project and felt confident in their ability to use this volatile fuel for rockets. They had already accepted Krafft Ehricke's arguments that hydrogen was the only practical fuel for upper stages, and started the Centaur project based on the strength of these arguments. Titan C was a hydrogen-burning intermediate stage that would normally sit between the Titan lower and Centaur upper, or could be used without the Centaur for low-Earth orbit missiles like Dyna-Soar. However, as hydrogen is much less dense than "traditional" fuels then in use, especially kerosene, the upper stage would have to be fairly large in order to hold enough fuel. As the Atlas and Titan were both built at 120" diameters it would make sense to build Titan C at this diameter as well, but this would result in an unwieldy tall and skinny rocket with dubious strength and stability. Instead, Titan C proposed building the new stage at a larger 160" diameter, meaning it would be an entirely new rocket. 

In comparison, the Super-Juno design was based on off-the-shelf components, with the exception of the E-1 engines. Although it too relied on the Centaur for high-altitude missions, the rocket was usable for low-Earth orbit without Centaur, which offered some flexibility in case Centaur ran into problems. ARPA agreed that the Juno proposal was more likely to meet the timeframes required, although they felt that there was no strong reason to use the E-1, and recommended a lower-risk approach here as well. ABMA responded with a new design, the Juno V (as a continuation of the Juno I and Juno II series of rockets, while Juno III and IV were unbuilt Atlas- and Titan-derived concepts), which replaced the four E-1 engines with eight H-1s, a much more modest upgrade of the existing S-3D already used on the Thor and Jupiter missiles, raising thrust from 150,000 to 188,000 lbf (670 to 840 kN). It was estimated that this approach would save as much as $60 million in development and cut as much as two years of R&D time.

Happy with the results of the redesign, on August 15, 1958 ARPA issued Order Number 14-59 that called on ABMA to:
Initiate a development program to provide a large space vehicle booster of approximately 1 500 000-lb. thrust based on a cluster of available rocket engines. The immediate goal of this program is to demonstrate a full-scale captive dynamic firing by the end of CY 1959.
This was followed on September 11, 1958 with another contract with Rocketdyne to start work on the H-1. On September 23, 1958, ARPA and the Army Ordnance Missile Command (AOMC) drew up an additional agreement enlarging the scope of the program, stating "In addition to the captive dynamic firing..., it is hereby agreed that this program should now be extended to provide for a propulsion flight test of this booster by approximately September 1960." Further, they wanted ABMA to produce three additional boosters, the last two of which would be "capable of placing limited payloads in orbit."

By this point many in the ABMA group were already referring to the design as Saturn, as von Braun explained it as a reference to the planet after Jupiter. The name change became official in February 1959.

NASA involvement

In addition to ARPA, various groups within the US government had been considering the formation of a civilian agency to handle space exploration. After the Sputnik launch, these efforts gained urgency and were quickly moved forward. NASA was formed on July 29, 1958, and immediately set about studying the problem of manned space flight, and the launchers needed to work in this field. One goal, even in this early stage, was a manned lunar mission. At the time, the NASA panels felt that the direct ascent mission profile was the best approach; this placed a single very large spacecraft in orbit, which was capable of flying to the Moon, landing and returning to Earth. To launch such a large spacecraft, a new booster with much greater power would be needed; even the Saturn was not nearly large enough. NASA started examining a number of potential rocket designs under their Nova program. 

NASA was not alone in studying manned lunar missions. von Braun had always expressed an interest in this goal, and had been studying what would be required for a lunar mission for some time. ABMA's Project Horizon proposed using fifteen Saturn launches to carry up spacecraft components and fuel that would be assembled in orbit to build a single very large lunar craft. This Earth orbit rendezvous mission profile required the least amount of booster capacity per launch, and was thus able to be carried out using the existing rocket design. This would be the first step towards a small manned base on the moon, which would require several additional Saturn launches every month to supply it. 

The Air Force had also started their Lunex Project in 1958, also with a goal of building a manned lunar outpost. Like NASA, Lunex favored the direct ascent mode, and therefore required much larger boosters. As part of the project, they designed an entirely new rocket series known as the Space Launcher System, or SLS (not to be confused with current SLS plans), which combined a number of solid-fuel boosters with either the Titan missile or a new custom booster stage to address a wide variety of launch weights. The smallest SLS vehicle consisted of a Titan and two strap-on solids, giving it performance similar to Titan C, allowing it to act as a launcher for Dyna-Soar. The largest used much larger solid-rockets and a much enlarged booster for their direct ascent mission. Combinations in-between these extremes would be used for other satellite launching duties.

Silverstein Committee

A government commission, the "Saturn Vehicle Evaluation Committee" (better known as the Silverstein Committee), was assembled to recommend specific directions that NASA could take with the existing Army program. The committee recommended the development of new, hydrogen-burning upper stages for the Saturn, and outlined eight different configurations for heavy-lift boosters ranging from very low-risk solutions making heavy use of existing technology, to designs that relied on hardware that had not been developed yet, including the proposed new upper stage. The configurations were:
  • Saturn A
    • A-1 – Saturn lower stage, Titan second stage, and Centaur third stage (von Braun's original concept)
    • A-2 – Saturn lower stage, proposed clustered Jupiter second stage, and Centaur third stage
  • Saturn B
    • B-1 – Saturn lower stage, proposed clustered Titan second stage, proposed S-IV third stage and Centaur fourth stage
  • Saturn C
    • C-1 – Saturn lower stage, proposed S-IV second stage
    • C-2 – Saturn lower stage, proposed S-II second stage, proposed S-IV third stage
    • C-3, C-4, and C-5 – all based on different variations of a new lower stage using F-1 engines, variations of proposed S-II second stages, and proposed S-IV third stages.
Contracts for the development of a new hydrogen-burning engine were given to Rocketdyne in 1960 and for the development of the Saturn IV stage to Douglas the same year.

Launch history

1965 graph showing cumulative history and projection of Saturn launches by month (along with Atlas and Titan)
 
Saturn Launch History 
PROGRAM VEHICLE MISSION LAUNCH
DATE
PAD
Saturn I SA-1 SA-1 Oct 27,-1961 LC-34
Saturn I SA-2 SA-2 Apr 25, 1962 34
Saturn I SA-3 SA-3 Nov 16, 1962 34
Saturn I SA-4 SA-4 Mar 28, 1963 34
Saturn I SA-5 SA-5 Jan 29, 1964 LC-37B
Saturn I SA-6 A-101 May 28, 1964 37B
Saturn I SA-7 A-102 Sep 18, 1964 37B
Saturn I SA-9 A-103 Feb 16, 1965 37B
Saturn I SA-8 A-104 May 25, 1965 37B
Saturn I SA-10 A-105 -Jul 30, 1965 37B
Saturn IB SA-201 AS-201 Feb 26, 1966 34
Saturn IB SA-203 AS-203 Jul 5, 1966 37B
Saturn IB SA-202 AS-202 Aug 25, 1966 34
Saturn V SA-501 Apollo 4 Nov 9, 1967 LC-39A
Saturn IB SA-204 Apollo 5 Jan 22, 1968 37B
Saturn V SA-502 Apollo 6 -Apr 4, 1968 39A
Saturn IB SA-205 Apollo 7 Oct 11, 1968 34
Saturn V SA-503 Apollo 8 Dec 21, 1968 39A
Saturn V SA-504 Apollo 9 Mar 3, 1969 39A
Saturn V SA-505 Apollo 10 May 18, 1969 LC-39B
Saturn V SA-506 Apollo 11 Jul 16, 1969 39A
Saturn V SA-507 Apollo 12 Nov 14, 1969 39A
Saturn V SA-508 Apollo 13 Apr 11, 1970 39A
Saturn V SA-509 Apollo 14 Jan 31, 1971 39A
Saturn V SA-510 Apollo 15 Jul 26, 1971 39A
Saturn V SA-511 Apollo 16 Apr 16, 1972 39A
Saturn V SA-512 Apollo 17 Dec 7, 1972 39A
Saturn V SA-513 Skylab 1 May 14, 1973 39A
Saturn IB SA-206 Skylab 2 May 25, 1973 39B
Saturn IB SA-207 Skylab 3 Jul 28, 1973 39B
Saturn IB SA-208 Skylab 4 Nov 16, 1973 39B
Saturn IB SA-210 ASTP 15-Jul-1975 39B

Project Apollo

The challenge that President John F. Kennedy put to NASA in May 1961 to put an astronaut on the Moon by the end of the decade put a sudden new urgency on the Saturn program. That year saw a flurry of activity as different means of reaching the Moon were evaluated.

Both the Nova and Saturn rockets, which shared a similar design and could share some parts, were evaluated for the mission. However, it was judged that the Saturn would be easier to get into production, since many of the components were designed to be air-transportable. Nova would require new factories for all the major stages, and there were serious concerns that they could not be completed in time. Saturn required only one new factory, for the largest of the proposed lower stages, and was selected primarily for that reason. 

The Saturn C-5 (later given the name Saturn V), the most powerful of the Silverstein Committee's configurations, was selected as the most suitable design. At the time the mission mode had not been selected, so they chose the most powerful booster design in order to ensure that there would be ample power. Selection of the lunar orbit rendezvous method reduced the launch weight requirements below those of the Nova, into the C-5's range.

At this point, however, all three stages existed only on paper, and it was realized that it was very likely that the actual lunar spacecraft would be developed and ready for testing long before the booster. NASA therefore decided to also continue development of the C-1 (later Saturn I) as a test vehicle, since its lower stage was based on existing technology (Redstone and Jupiter tankage) and its upper stage was already in development. This would provide valuable testing for the S-IV as well as a launch platform for capsules and other components in low earth orbit.

The members of the Saturn family that were actually built were:
  • Saturn I – ten rockets flown: five development flights, and five launches of boilerplate Apollo spacecraft and Pegasus micrometeroid satellites.
  • Saturn IB – nine launches; a refined version of the Saturn I with a more powerful first stage (designated the S-IB) and using the Saturn V's S-IVB as a second stage. These carried the first Apollo flight crew, plus three Skylab and one Apollo-Soyuz crews, into Earth orbit.
  • Saturn V – 13 launches; the Moon rocket that sent Apollo astronauts to the Moon, and carried the Skylab space station into orbit.

Algorithmic information theory

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