The
Saturn family of
rocketA rocket or rocket vehicle is a missile, spacecraft, aircraft or other vehicle which obtains thrust by the reaction of the rocket to the ejection of a jet of fast moving fluid exhaust from a rocket engine. Chemical rockets create their exhaust by the combustion of rocket propellant...
s were developed by a team of mostly German rocket scientists led by
Wernher von BraunWernher Magnus Maximilian Freiherr von Braun was a German American rocket physicist and astronautics engineer, becoming one of the leading figures in the development of rocket technology in Germany and the United States...
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 program. The two most important members of the family were the Saturn IB and the
Saturn VThe Saturn V was a multistage liquid-fuel expendable rocket used by NASA's Apollo and Skylab programs from 1967 until 1973. In total NASA launched thirteen Saturn V rockets with no loss of payload. It remains the largest and most powerful launch vehicle ever brought to operational status from a...
.
Early development
In the early 1950s all of the major branches of the US military were actively developing long-range missiles, including the US Navy's
VikingThe Viking rocket series of sounding rockets were designed and built by the Glenn L. Martin Company under the direction of the U.S. Naval Research Laboratory . A total of twelve Viking rockets flew from 1949 to 1955.- Origins :...
and US Army's
CorporalThe American-made MGM-5 Corporal missile was the first Guided Weapon authorised by the US to carry a nuclear warhead. A surface-to-surface guided missile, the Corporal could deliver either a nuclear fission or high-explosive warhead up to a range of ....
, Jupiter and
RedstoneFirst launched in 1953, the American Redstone rocket was a direct descendant of the German V-2. Redstone was used for the first live nuclear missile tests by the United States...
, developed primarily by Germans from the
V-2According to head of Nazi rocket program Walter Dornberger, the V-2 rocket was the world's first ballistic missile and first human artifact to achieve sub-orbital spaceflight. It was the progenitor of all modern rockets...
project and based on its technology. The US Air Force's
AtlasAtlas is a family of U.S. space launch vehicles. The original Atlas missile was designed in the late 1950s. It was a liquid-fuel rocket burning LOX and RP-1 in three engines configured in an unusual "stage-and-a-half" or "Parallel Staging" design: two of its three engines were jettisoned during...
and
TitanTitan was a family of U.S. expendable rockets used between 1959 and 2005. A total of 368 rockets of this family were launched.-Titan I:The Titan I was the first version of the Titan family of rockets. It began as a backup ICBM project in case the Atlas was delayed. It was a two-stage rocket...
used more technology developed in U.S.
In-fighting between the various branches was constant, with the
United States Department of DefenseThe United States Department of Defense is the federal department charged with coordinating and supervising all agencies and functions of the government relating directly to national security and the military...
(DoD) often called upon to decide which projects to fund for development. Things were supposed to be settled by the 26 November 1956 "Wilson Memorandum," which stripped the Army of offensive missiles with a range of 200 miles or greater and forced their Jupiter missiles to be turned 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 for space launchers.
Some time in late 1956 or early 1957 the Department of Defense released a requirement for a heavy-lift vehicle to orbit a new class of communications and "other" satellites (the
spy satelliteA spy satellite is an Earth observation satellite or communications satellite deployed for military or intelligence applications....
program was
top secretTop Secret generally refers to the highest acknowledged level of classified information.Top Secret or Top Secret! may also refer to:*Top Secret , codename for an experimental multiplayer online game collaboration...
). 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 launchers, the
Army Ballistic Missile AgencyThe Army Ballistic Missile Agency was the agency formed to develop the US Army's first intermediate range ballistic missile. It was established at Redstone Arsenal on February 1, 1956 and commanded by Major General John B...
(ABMA) saw this as a way to continue development of their own projects. In April 1957, von Braun directed
Heinz-Hermann KoelleHeinz-Hermann Koelle is an aeronautical engineer who made the preliminary designs on the rocket that would emerge as the Saturn I. Closely associated with Werner von Braun's team at the Army Ballistic Missile Agency , he was a member of the launch crew on Explorer I and later directed the Marshall...
, chief of the Future Projects design branch, to study dedicated space launcher 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 need for loads of 10,000 kg or greater, the ABMA calculated that a booster (first stage) with a thrust of about 1.5 million pounds thrust (lbf) 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 concepts named "Super-Atlas", "Super-Titan", and "Super-Jupiter". Super-Jupiter received the most attention because it used hardware developed by ABMA; the Titan and Atlas were Air Force designs that were suffering from lengthy delays in development.
Two approaches to building the Super-Jupiter were considered; the first used multiple engines to reach the 1.5 million lbf (6.7 MN) 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 (paradoxically, adding engines generally
reduces reliability). A single larger engine would be more reliable in theory, and would offer higher performance because it eliminated duplication of "dead weight" like fuel plumbing and hydraulics for steering the engines, but 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-1The F-1 is a rocket engine developed by Rocketdyne and used in the Saturn V. Five F-1 engines were used in the S-IC first stage of each Saturn V, which served as the main launch vehicle in the Apollo program...
, but at the time they were aiming for 1 million lbf 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
CentaurCentaur is a rocket stage designed for use as the upper stage of space launch vehicles. Centaur boosts its satellite payload to its final orbit or, in the case of an interplanetary space probe, to escape velocity...
upper-stage. The Centaur had been proposed by
General DynamicsGeneral Dynamics Corporation is a U.S. defense conglomerate formed by mergers and divestitures, and as of 2008 it is the fifth largest defense contractor in the world. The company has changed markedly in the post-Cold War era of defense consolidation. The company has four main business segments:...
(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 lbs 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 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-1Rocketdyne's E-1 was a liquid propellant rocket engine originally built as a backup design for the Titan I missile. While it was being developed, Heinz-Hermann Koelle at the Army Ballistic Missile Agency selected it as the primary engine for the rocket that would emerge as the Saturn I...
engines of 360 to 380,000 lbf. The ABMA team also left the design open to future expansion with a single 1.5 million lbf 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 YearThe International Geophysical Year was an international scientific effort that lasted from July 1, 1957, to December 31, 1958.The IGY encompassed eleven Earth sciences: aurora and airglow, cosmic rays, geomagnetism, gravity, ionospheric physics, longitude and latitude determinations , meteorology,...
in 1957. For complex reasons, the program had been given to the US Navy under
Project VanguardProject Vanguard was a program managed by the United States Naval Research Laboratory , which intended to launch the first artificial satellite into Earth orbit using a Vanguard rocket as the launch vehicle....
. The Vanguard launcher consisted of a
VikingThe Viking rocket series of sounding rockets were designed and built by the Glenn L. Martin Company under the direction of the U.S. Naval Research Laboratory . A total of twelve Viking rockets flew from 1949 to 1955.- Origins :...
lower stage combined with new uppers adapted from
sounding rocketA sounding rocket, sometimes called a research rocket, is an instrument-carrying rocket designed to take measurements and perform scientific experiments during its sub-orbital flight. The origin of the term comes from nautical vocabulary, it refers to to sound, which means to throw a weighted...
s. 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.
To everyone's amazement, on 4 October 1957 the
Soviet UnionThe Union of Soviet Socialist Republics was a constitutionally socialist state that existed in Eurasia from 1922 to 1991. The name is a translation of the , tr. Soyuz Sovetskikh Sotsialisticheskikh Respublik, abbreviated СССР, SSSR. The common short name is Soviet Union, from , Sovetskiy Soyuz...
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. 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 with the solid-fuel engines from the Vanguard, producing the
Juno IThe Juno I was a satellite launch vehicle, derived from, and commonly confused with, the Jupiter-C sounding rocket. It is most well known for launching America's first satellite, Explorer 1....
. 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 IExplorer 1 was the first Earth satellite of the United States, launched on February 1, 1958 at 03:48 UTC from LC-26 at Cape Canaveral Air Force Station as part of the United States program for the International Geophysical Year and in response to the launch of the Soviet satellite Sputnik 1...
on February 1, 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 space launchers 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 7 February 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 hydrogenLiquid hydrogen is the liquid state of the element hydrogen. Hydrogen is found naturally in the molecular H
2 form....
on the Lockheed CL-400 Suntan spy plane project and felt confidant in their ability to use this volatile fuel for rockets. They had already accepted Krafft Ehricke arguments 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, essentially
keroseneKerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
, the upper stage would have to 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 unwieldily 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 IThe Juno I was a satellite launch vehicle, derived from, and commonly confused with, the Jupiter-C sounding rocket. It is most well known for launching America's first satellite, Explorer 1....
and
Juno IIThe Juno II was an American rocket used during the late 1950s and early 1960s. It was derived from the Jupiter missile, which was used as the first stage. Sergeant rocket motors were used as upper stages - eleven for the second stage, three for the third stage, and one for the fourth stage - the...
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-1Rocketdyne's H-1 is a thrust liquid fuel rocket engine burning LOX and RP-1. The H-1 was developed for use in the S-IB first stage of the Saturn I and Saturn IB rockets, where it was used in clusters of eight engines...
s, 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 15 August 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 11 September 1958 with another contract with Rocketdyne to start work on the H-1. On 23 September 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, 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.
NASAThe National Aeronautics and Space Administration is an agency of the United States government, responsible for the nation's public space program. NASA was established by the National Aeronautics and Space Act on July 29, 1958, replacing its predecessor, the National Advisory Committee for...
was formed on 29 July 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 ascentDirect ascent was a proposed method for a mission to the Moon. In the United States, direct ascent proposed using the enormous Nova rocket or Saturn C-8 to loft a spacecraft directly to the Moon, where it would land tail-first and then launch off the Moon back to Earth...
mission profile was the best approach; this placed a single very large spacecraft in orbit, which was capable of flying to the
MoonThe Moon is Earth's only natural satellite and the fifth largest satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is , about thirty times the diameter of the Earth. The common centre of mass of the system is located at about —a quarter the Earth's...
, 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 HorizonProject Horizon was a study to determine the feasibility of constructing a military base on the Moon. On 8 June, 1959, a group at the Army Ballistic Missile Agency produced for the U.S. Department of the Army a report entitled Project Horizon, A U.S. Army Study for the Establishment of a Lunar...
proposed using fifteen Saturn launches to carry up spacecraft components and fuel that would be assembled in orbit to built a single very large lunar craft. This
Earth orbit rendezvousEarth orbit rendezvous is type of space rendezvous, a method that has been proposed for space missions to the Moon. NASA considered an EOR mission profile for the Apollo program, but chose instead to use lunar 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 ProjectThe Lunex Project was a US Air Force 1958 plan for a manned lunar landing prior to the Apollo Program. The final lunar expedition plan in 1961 was for a 21-airman underground Air Force base on the moon by 1968 at a total cost of $ 7.5 billion....
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 Launch System (SLS), 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 assent 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 CommitteeThe Saturn Vehicle Evaluation Committee, better known as the Silverstein Committee, was a US government commission assembled in 1959 to recommend specific directions that NASA could take with the Saturn program...
), was assembled to recommend specific directions that NASA could take with the 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 cluster lower stage, Titan second stage, and Centaur third stage (von Braun's original concept)
- A-2 - Saturn cluster lower stage, proposed Jupiter cluster second stage, and Centaur third stage
- Saturn B
- B-1 - Saturn cluster lower stage, proposed Titan cluster second stage, proposed S-IV
The S-IV was the second stage of the Saturn I, a rocket-powered launch vehicle used by NASA for early flights in the Apollo program.The S-IV is similar to, but distinct from, the later S-IVB stage used on the Saturn IB and Saturn V rockets....
third stage and Centaur fourth stage
- Saturn C
- C-1 - Saturn cluster lower stage, proposed S-IV
The S-IV was the second stage of the Saturn I, a rocket-powered launch vehicle used by NASA for early flights in the Apollo program.The S-IV is similar to, but distinct from, the later S-IVB stage used on the Saturn IB and Saturn V rockets....
second stage
- C-2 - Saturn cluster lower stage, proposed S-II
The S-II was the second stage of the Saturn V rocket. It was built by North American Aviation. Using liquid hydrogen and liquid oxygen it had five J-2 engines in a cross pattern...
second stage, and 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 was given to Rocketdyne in 1960 and for the development of the Saturn IV stage to
DouglasThe Douglas Aircraft Company was an American aerospace manufacturer, based in Long Beach, California. It was founded in 1921 by Donald Wills Douglas, Sr. and later merged with McDonnell Aircraft in 1967 to form McDonnell Douglas. It is currently a part of Boeing's Commercial Airplanes...
the same year.
Project Apollo
The challenge that President
John F. KennedyJohn Fitzgerald "Jack" Kennedy , often referred to by his initials JFK, was the 35th President of the United States, serving from 1961 until his assassination in 1963....
put to NASA in May 1961 to put an
astronautAn astronaut or cosmonaut is a person trained by a human spaceflight program to command, pilot, or serve as a crew member of a spacecraft....
on the
MoonThe Moon is Earth's only natural satellite and the fifth largest satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is , about thirty times the diameter of the Earth. The common centre of mass of the system is located at about —a quarter the Earth's...
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
NovaNova was a series of proposed rocket designs, originally as NASA's first large launchers for missions similar to the Saturn V that entered production, and later as larger follow-ons to the Saturn V intended for missions to Mars. The two series of designs were essentially separate, but shared their...
and Saturn rockets were evaluated for the mission, which shared a similar design and could share some parts. 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.
NovaNova was a series of proposed rocket designs, originally as NASA's first large launchers for missions similar to the Saturn V that entered production, and later as larger follow-ons to the Saturn V intended for missions to Mars. The two series of designs were essentially separate, but shared their...
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, and was selected primarily for that reason.
The Saturn C-5, (later given the name
Saturn VThe Saturn V was a multistage liquid-fuel expendable rocket used by NASA's Apollo and Skylab programs from 1967 until 1973. In total NASA launched thirteen Saturn V rockets with no loss of payload. It remains the largest and most powerful launch vehicle ever brought to operational status from a...
), 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. This proved to be wise decision; although the
Lunar orbit rendezvousLunar orbit rendezvous is a key concept for human landing on the Moon and returning back to Earth.In an LOR mission a main spacecraft and a smaller lunar module travel together into lunar orbit. The lunar module then independently descends to the lunar surface. After completion of the mission...
was eventually selected and reduced the launch weight requirements, as the weight of the spacecraft crept upwards the extra launch capability of the C-5 proved very useful.
At this point, however, all three stages existed only on paper, and it was realised 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 IThe Saturn I was the United States' first dedicated "space launcher," a rocket designed specifically to launch loads into Earth's orbit. Most of the rocket's power came from a "clustered" lower stage consisting of tanks taken from older rocket designs and strapped together to make a single larger...
) 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.
Ultimately, the members of the Saturn family that made it to the launch pad were:
- Saturn I
The Saturn I was the United States' first dedicated "space launcher," a rocket designed specifically to launch loads into Earth's orbit. Most of the rocket's power came from a "clustered" lower stage consisting of tanks taken from older rocket designs and strapped together to make a single larger...
- ten rockets flown to evaluate the S-I and, in later flights, the S-IV stages.
- Saturn IB
The Saturn IB was an uprated version of the Saturn I, which featured a much more powerful second stage, the S-IVB. Unlike the earlier Saturn I, the IB had enough throw weight to launch the Apollo Command/Service Module or Lunar Module into Earth orbit, which made it invaluable for testing the...
- nine launches, a refined version of the Saturn I with a more powerful first stage (designated the S-IBThe S-IB stage was an eight engine booster for Earth orbital missions. It was composed of nine propellant containers, eight fins, a thrust structure assembly, eight H-1 rocket engines, and many other components. The propellant containers consisted of eight Redstone tanks clustered around a ...
) and using the Saturn V's S-IVBThe S-IVB was built by the Douglas Aircraft Company and served as the third stage on the Saturn V and second stage on the Saturn IB. It had one J-2 engine...
as a second stage. These carried the first crewed Apollo flights into orbit, and later provided the boosters for the SkylabSkylab was the United States' first space station, and the second space station visited by a human crew. It was also the only space station NASA launched alone...
and Apollo-SoyuzThe Apollo-Soyuz Test Project was the last mission in the Apollo program and was the first joint flight of the U.S. and Soviet space programs. The mission took place in July 1975...
flights.
- Saturn V
The Saturn V was a multistage liquid-fuel expendable rocket used by NASA's Apollo and Skylab programs from 1967 until 1973. In total NASA launched thirteen Saturn V rockets with no loss of payload. It remains the largest and most powerful launch vehicle ever brought to operational status from a...
- 12 launches, the Moon rocket that carried Apollo astronauts to the Moon.
- Saturn INT-21
The Saturn INT-21 was an American orbital launch vehicle of the 1970s. It was derived from the Saturn V rocket used for the Apollo program, and is casually referred to as a "modified Saturn V." It was only launched once, from Kennedy Space Center at Cape Canaveral, carrying the Skylab space...
- one launch, used to place the SkylabSkylab was the United States' first space station, and the second space station visited by a human crew. It was also the only space station NASA launched alone...
space stationA space station is an artificial structure designed for humans to live in outer space. To date, only low earth orbital stations have been implemented, otherwise known as orbital stations...
in orbit.
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