E-1 (rocket engine)
Encyclopedia
Rocketdyne
'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
(ABMA) selected it as the primary engine for the rocket that would emerge as the Saturn I
. In the end, the Titan went ahead with its primary engine, and the Saturn decided to use the lower-thrust H-1
in order to speed development. The E-1 project was cancelled in 1959, but Rocketdyne's success with the design gave NASA
confidence in Rocketdyne's ability to deliver the much larger F-1
, which powered the Saturn V
to the Moon.
SAC's concerns were taken to heart within the Air Force, and they directed Ramo-Wooldridge
to study the issue. Ramo responded by inviting Lockheed
and the Glenn L. Martin Company
to propose alternative ICBM designs. Based on these reports, Ramo suggested that the Air Force begin development of a new missile that used a conventional airframe in place of the Atlas's "balloon tanks", and replaced the "stage and a half" layout with a two-stage design.
. Aerojet General was selected to build the engines for the design, developing the two-chamber LR-87
on the booster and the single LR-91 on the upper stage. In keeping with the low-risk development concept underpinning the entire Titan project, WDD also selected North American Aviation
's Rocketdyne Division to develop a backup engine.
Rocketdyne, which was spun off as a separate company in 1955, decided to meet the needs for the ~350000 lbf (1,556.9 kN) thrust requirements with a single engine, as opposed to a cluster of smaller engines. Starting with the basic layout from their successful MB-3/S-3 (known to the Air Force as the LR-79) from the Thor
and Jupiter missiles, Rocketdyne developed the E-1 by expanding its size and tuning the engine bell for operation at lower altitudes. At higher altitudes the upper stage would be firing.
Development of the E-1 was rapid and prototypes were sent to the Santa Susana Field Laboratory
later in 1955. However, development of a stable fuel injector proved difficult, and took 18 months to fully solve. Over a series of months the thrust was increased until it developed over 379,837 lbf (1,689 kN) at sea level
. A complete booster stage equipped with the E-1 was fired on 10 January 1956.
with the development of a space launch system to meet new requirements specified by the then-unofficial ARPA
. Koelle concluded that in order to meet their payload requirements, 10,000 to 20000 lb (9,071.8 kg) into low earth orbit
, a booster stage with 1 million pounds of thrust would be needed.
Looking for an engine able to develop these sorts of power levels, he learned about the E-1 from Rocketdyne's George Sutton. The E-1 was, by far, the most powerful engine that could be available in the time frame that ARPA was demanding. Koelle selected a cluster of four E-1's as the basis of a new booster they called the "Juno V" (the latest in a series of Juno designs, launcher adapted from missiles). The engines were attached to a single thrust plate, and supplied fuel from a cluster of tanks taken from the existing Jupiter and Redstone missile airframes. Later that year the team started referring to the design as the "Saturn", for "the one after Jupiter", Jupiter being ABMA's latest successful rocket design. The name stuck and became official in early 1959.
After the launch of Sputnik I on 4 October 1957, the U.S. was in a panic
over how to quickly catch up with the Soviets in what appeared to be a "space race
". One idea quickly gained currency, the formation of a civilian space agency that would evolve into NASA
. The Army had already lost interest in the development of the Saturn due to a lack of mission requirements, and had agreed to turn over the ABMA team to NASA on 1 July 1960.
In July 1958 von Braun was visited by Dick Canright and Bob Young of ARPA, who informed von Braun they still had $10 million left in their budget to spend before ABMA was turned over to NASA. von Braun called in Koelle, who presented a 1/10 scale model of the Juno V, still equipped with the E-1 engine. Canright and Young noted that the engine wouldn't be ready in time for the handoff, and asked if the rocket could be built with an existing engine instead. Koelle suggested that eight engines from the existing S-3D series could be used in place of the E-1, and everyone approved.
Development of the Saturn moved ahead with a slightly upgraded version of the S-3D, known as the H-1
. When NASA started the process of taking over ABMA, they decided that the project was worthwhile, and continued funding its development.
(refined kerosene
similar to jet fuel) and liquid oxygen
. Turbopumps were powered by a gas generator
which dumped the burned fuel overboard. Thrust was ~380000 lbf (1,690.3 kN) at sea level, rising to ~425000 lbf (1,890.5 kN) in vacuum, corresponding to a rise in specific impulse
from 260 seconds to 290. The entire combustion chamber and engine bell were regeneratively cooled using a system similar to the S-3 and later F-1.
Rocketdyne
Rocketdyne was a Rocket engine design and production company headquartered in Canoga Park, California, United States. The company was related to North American Aviation for most of its history. NAA merged with Rockwell International, which was then bought by Boeing in December, 1996...
's E-1 was a liquid propellant rocket engine
Rocket engine
A rocket engine, or simply "rocket", is a jet engineRocket Propulsion Elements; 7th edition- chapter 1 that uses only propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines and obtain thrust in accordance with Newton's third law...
originally built as a backup design for the Titan I
Titan I
The Martin Marietta SM-68A/HGM-25A Titan I was the United States' first multistage ICBM . Incorporating the latest design technology when designed and manufactured, the Titan I provided an additional nuclear deterrent to complement the U.S. Air Force's SM-65 Atlas missile...
missile. While it was being developed, Heinz-Hermann Koelle
Heinz-Hermann Koelle
Heinz-Hermann Koelle was an aeronautical engineer who made the preliminary designs on the rocket that would emerge as the Saturn I...
at the Army Ballistic Missile Agency
Army Ballistic Missile Agency
The 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) selected it as the primary engine for the rocket that would emerge as the Saturn I
Saturn I
The Saturn I was the United States' first heavy-lift dedicated space launcher, a rocket designed specifically to launch large payloads into low Earth 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...
. In the end, the Titan went ahead with its primary engine, and the Saturn decided to use the lower-thrust H-1
H-1 (rocket engine)
Rocketdyne's H-1 is a thrust liquid-propellant 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...
in order to speed development. The E-1 project was cancelled in 1959, but Rocketdyne's success with the design gave NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
confidence in Rocketdyne's ability to deliver the much larger F-1
F-1 (rocket engine)
The 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. The F-1 is still the most powerful single-chamber liquid-fueled rocket engine ever...
, which powered the Saturn V
Saturn V
The Saturn V was an American human-rated expendable rocket used by NASA's Apollo and Skylab programs from 1967 until 1973. A multistage liquid-fueled launch vehicle, NASA launched 13 Saturn Vs from the Kennedy Space Center, Florida with no loss of crew or payload...
to the Moon.
Genesis
In July 1954 the Air Force Scientific Advisory Board's ICBM working group advised the Western Development Division (WDD) on their doubts about the Atlas missile that was then under development. Atlas used a number of unconventional features in order to meet its performance goals, and they felt that there was undue risk that if any of these proved unworkable in practice then the entire design would fail. The group suggested that a second ICBM project be started as a risk mitigation effort.SAC's concerns were taken to heart within the Air Force, and they directed Ramo-Wooldridge
TRW
TRW Inc. was an American corporation involved in a variety of businesses, mainly aerospace, automotive, and credit reporting. It was a pioneer in multiple fields including electronic components, integrated circuits, computers, software and systems engineering. TRW built many spacecraft,...
to study the issue. Ramo responded by inviting Lockheed
Lockheed Corporation
The Lockheed Corporation was an American aerospace company. Lockheed was founded in 1912 and later merged with Martin Marietta to form Lockheed Martin in 1995.-Origins:...
and the Glenn L. Martin Company
Glenn L. Martin Company
The Glenn L. Martin Company was an American aircraft and aerospace manufacturing company that was founded by the aviation pioneer Glenn L. Martin. The Martin Company produced many important aircraft for the defense of the United States and its allies, especially during World War II and the Cold War...
to propose alternative ICBM designs. Based on these reports, Ramo suggested that the Air Force begin development of a new missile that used a conventional airframe in place of the Atlas's "balloon tanks", and replaced the "stage and a half" layout with a two-stage design.
Titan
Selecting from the two proposals, a contract was awarded to Martin for what emerged as the TitanTitan I
The Martin Marietta SM-68A/HGM-25A Titan I was the United States' first multistage ICBM . Incorporating the latest design technology when designed and manufactured, the Titan I provided an additional nuclear deterrent to complement the U.S. Air Force's SM-65 Atlas missile...
. Aerojet General was selected to build the engines for the design, developing the two-chamber LR-87
LR-87
The LR-87 was a liquid-propellent rocket engine, which was used to propel the first stages of Titan intercontinental ballistic missiles and launch vehicles. Though this powerful engine used two discrete combustion chambers, it is considered a single unit owing to both chambers using common...
on the booster and the single LR-91 on the upper stage. In keeping with the low-risk development concept underpinning the entire Titan project, WDD also selected North American Aviation
North American Aviation
North American Aviation was a major US aerospace manufacturer, responsible for a number of historic aircraft, including the T-6 Texan trainer, the P-51 Mustang fighter, the B-25 Mitchell bomber, the F-86 Sabre jet fighter, the X-15 rocket plane, and the XB-70, as well as Apollo Command and Service...
's Rocketdyne Division to develop a backup engine.
Rocketdyne, which was spun off as a separate company in 1955, decided to meet the needs for the ~350000 lbf (1,556.9 kN) thrust requirements with a single engine, as opposed to a cluster of smaller engines. Starting with the basic layout from their successful MB-3/S-3 (known to the Air Force as the LR-79) from the Thor
PGM-17 Thor
Thor was the first operational ballistic missile of the U.S. Air Force . Named after the Norse god of thunder, it was deployed in the United Kingdom between 1959 and September 1963 as an intermediate range ballistic missile with thermonuclear warheads. Thor was in height and in diameter. It was...
and Jupiter missiles, Rocketdyne developed the E-1 by expanding its size and tuning the engine bell for operation at lower altitudes. At higher altitudes the upper stage would be firing.
Development of the E-1 was rapid and prototypes were sent to the Santa Susana Field Laboratory
Santa Susana Field Laboratory
The Santa Susana Field Laboratory is a complex of industrial research and development facilities located on a 2,668 acre portion of the Southern California Simi Hills in Simi Valley, California, used mainly for the testing and development of Liquid-propellant rocket engines for the United States...
later in 1955. However, development of a stable fuel injector proved difficult, and took 18 months to fully solve. Over a series of months the thrust was increased until it developed over 379,837 lbf (1,689 kN) at sea level
Sea level
Mean sea level is a measure of the average height of the ocean's surface ; used as a standard in reckoning land elevation...
. A complete booster stage equipped with the E-1 was fired on 10 January 1956.
Saturn
In April 1957 Werner von Braun tasked Heinz-Hermann KoelleHeinz-Hermann Koelle
Heinz-Hermann Koelle was an aeronautical engineer who made the preliminary designs on the rocket that would emerge as the Saturn I...
with the development of a space launch system to meet new requirements specified by the then-unofficial ARPA
ARPA
Arpa and ARPA may refer to:Arpa* Arpa River in Armenia* Areni, Armenia - formerly called Arpa* Arpi, Armenia, also called Arpa* Turkish for Akhurian River in Turkey and Armenia* Italian for harp, sometimes used in scoresARPA...
. Koelle concluded that in order to meet their payload requirements, 10,000 to 20000 lb (9,071.8 kg) into low earth orbit
Low Earth orbit
A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...
, a booster stage with 1 million pounds of thrust would be needed.
Looking for an engine able to develop these sorts of power levels, he learned about the E-1 from Rocketdyne's George Sutton. The E-1 was, by far, the most powerful engine that could be available in the time frame that ARPA was demanding. Koelle selected a cluster of four E-1's as the basis of a new booster they called the "Juno V" (the latest in a series of Juno designs, launcher adapted from missiles). The engines were attached to a single thrust plate, and supplied fuel from a cluster of tanks taken from the existing Jupiter and Redstone missile airframes. Later that year the team started referring to the design as the "Saturn", for "the one after Jupiter", Jupiter being ABMA's latest successful rocket design. The name stuck and became official in early 1959.
After the launch of Sputnik I on 4 October 1957, the U.S. was in a panic
Sputnik crisis
The Sputnik crisis is the name for the American reaction to the success of the Sputnik program. It was a key event during the Cold War that began on October 4, 1957 when the Soviet Union launched Sputnik 1, the first artificial Earth satellite....
over how to quickly catch up with the Soviets in what appeared to be a "space race
Space Race
The Space Race was a mid-to-late 20th century competition between the Soviet Union and the United States for supremacy in space exploration. Between 1957 and 1975, Cold War rivalry between the two nations focused on attaining firsts in space exploration, which were seen as necessary for national...
". One idea quickly gained currency, the formation of a civilian space agency that would evolve into NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
. The Army had already lost interest in the development of the Saturn due to a lack of mission requirements, and had agreed to turn over the ABMA team to NASA on 1 July 1960.
In July 1958 von Braun was visited by Dick Canright and Bob Young of ARPA, who informed von Braun they still had $10 million left in their budget to spend before ABMA was turned over to NASA. von Braun called in Koelle, who presented a 1/10 scale model of the Juno V, still equipped with the E-1 engine. Canright and Young noted that the engine wouldn't be ready in time for the handoff, and asked if the rocket could be built with an existing engine instead. Koelle suggested that eight engines from the existing S-3D series could be used in place of the E-1, and everyone approved.
Development of the Saturn moved ahead with a slightly upgraded version of the S-3D, known as the H-1
H-1 (rocket engine)
Rocketdyne's H-1 is a thrust liquid-propellant 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...
. When NASA started the process of taking over ABMA, they decided that the project was worthwhile, and continued funding its development.
Cancellation
When Aerojet successfully demonstrated the LR-87, the Titan moved ahead with this engine and the first production example was delivered to the Air Force in 1958. Koelle considered continuing funding development of the E-1 from his budget but decided against it. As von Braun later noted, the development costs were too high for what would have given them a small performance boost, especially when the F-1 could replace all of the E-1s for an even greater advantage. Rocketdyne requested that the Air Force drop their interest in the E-1, which they did, and development of the engine ended.Description
The E-1 was a single-chamber liquid fuel engine burning RP-1RP-1
RP-1 is a highly refined form of kerosene outwardly similar to jet fuel, used as a rocket fuel. Although having a lower specific impulse than liquid hydrogen , RP-1 is cheaper, can be stored at room temperature, is far less of an explosive hazard and is far denser...
(refined kerosene
Kerosene
Kerosene, sometimes spelled kerosine in scientific and industrial usage, also known as paraffin or paraffin oil in the United Kingdom, Hong Kong, Ireland and South Africa, is a combustible hydrocarbon liquid. The name is derived from Greek keros...
similar to jet fuel) and liquid oxygen
Liquid oxygen
Liquid oxygen — abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries — is one of the physical forms of elemental oxygen.-Physical properties:...
. Turbopumps were powered by a gas generator
Gas generator
A gas generator usually refers to a device, often similar to a solid rocket or a liquid rocket that burns to produce large volumes of relatively cool gas, instead of maximizing the temperature and specific impulse. The low temperature allows the gas to be put to use more easily in many...
which dumped the burned fuel overboard. Thrust was ~380000 lbf (1,690.3 kN) at sea level, rising to ~425000 lbf (1,890.5 kN) in vacuum, corresponding to a rise in specific impulse
Specific impulse
Specific impulse is a way to describe the efficiency of rocket and jet engines. It represents the derivative of the impulse with respect to amount of propellant used, i.e., the thrust divided by the amount of propellant used per unit time. If the "amount" of propellant is given in terms of mass ,...
from 260 seconds to 290. The entire combustion chamber and engine bell were regeneratively cooled using a system similar to the S-3 and later F-1.
Further reading
- Robert Kraemer, "Rocketdyne: Powering Humans into Space", American Institute of Aeronautics and Astronautics, 2005, ISBN 1563477548
External links
- E-1 page on astronautics.com (includes an image of the E-1 being fired)