The Santa Susana Field Laboratory (SSFL) is located on 2,850 acres in the Simi Hills, nearly thirty miles northwest of downtown
Los Angeles, California, in southeastern Ventura County (close to the communities of Santa Susana Knolls, Bell Canyon and
Simi Valley). The SSFL, opened in 1948, is divided into four "Administrative Areas" and additional undeveloped
areas of land to the north and south. Areas I, III,
and IV and the undeveloped areas are owned and operated by the Boeing Company. Area
II, consisting of 409.5 acres, along with 41.7 acres in Area I, are owned by the U.S. Government and held by NASA. The U.S. Department of Energy (DOE) has long held a lease
on land in Area IV. No site-related operations were conducted in the undeveloped portions
of SSFL. NASA, Boeing and
conducted research and testing at SSFL over the years and each has responsibility for environmental cleanup in areas in
which it operated. California’s Department of Toxic Substances Control (DTSC) is
overseeing the cleanup under the Resource Conservation and Recovery Act (RCRA).
See also NASA's Historic Resources Survey and Assessment (PDF, 4.8MB) report. NASA would like to thank Reid Bogert
for his contribution in enhancing the usability of this document with navigational features and embedded search index.
NASA-adminstered property at the SSFL includes a 41.7-acre of Area I and Area II (409.5 acres)
Prehistory to 1900
Three Native American groups occupied Ventura County in the areas surrounding the Simi Hills during late prehistory: the
Chumash, the Tongva, and the Tataviam. All were seminomadic hunter-gatherers, while the Chumash and Tongva focused much
of their subsistence activities on marine resources, supplementing that with resources available inland.
Burro Flats Painted Cave is a prehistoric archaeological site located in the southwestern corner of Area II that is famous for its many pictographs (rock art paintings) and petroglyphs (rock art that has
been scored or incised into the rock surface). The site also includes evidence of habitation. The Chumash of the Simi Valley
and Simi Hills and the Tongva of the San Fernando Valley may both have visited the Burro Flats Painted Cave area. There
is speculation that the area may have been an interface between the two groups, and the rock art has been described as suggesting
Burro Flats Painted Cave was first occupied from at least A.D. 1100 until ca. A.D. 1810 to 1820, although its occupation
may extend back in time to as early as A.D. 900.
SSFL in the 1900s
After World War II, North American Aviation (NAA) leased and later purchased land in
the Simi Hills for rocket engine testing. NAA formed the aerospace company called Rocketdyne, which later merged with Rockwell
International Corporation (referred to here as Rockwell. Both the Rockwell and Rocketdyne names were associated with SSFL.
In 1954, NAA obtained an adjacent 838-acre area of undeveloped land from Henry Silvernale and Elizabeth Hall. (Property
ownership records identify Henry Silvernale and Elizabeth Hall as the earliest recorded owners of the property.) This new
parcel included the land that would become Area II, as well as the 41.7
acres in Area I that later would make up the LOX (Liquid Oxygen) plant. These portions
subsequently were transferred to the U.S. government.
In December 1958, NAA deeded three parcels of the former Silvernale property to the U.S. Air Force (USAF). Parcels 1 and
2, consisting of 409.5 acres, became the site of USAF Plant 57, now Area II. Parcel
3 was used for USAF Plant 64, now the LOX plant. The Grant Deed also granted legal access for roads.
Since 1954, Area II has been operated by Boeing, Rockwell, and its predecessor, NAA,
under USAF facility contracts. In 1973, the USAF Plant 57 (Area II) land was transferred
to NASA and the USAF Plant 57 designation was no longer used.
In 1976, the U.S. General Services Administration (GSA) transferred the LOX plant (USAF Plant 64) from the USAF to NASA,
but the Air Force retained possession of the structures. Under the terms of a facilities contract, Rockwell administered
the LOX plant for NASA. The LOX plant was removed in the early 1970s with the exception of a small weigh station and concrete
SSFL Operations Overview
The Santa Susana Field Laboratory (SSFL) supported rocket engine static testing for the nearly five decades of its active
lifespan. This testing provided pivotal data for the development and improvement of many weapons and space vehicles from
the Redstone rocket to the Atlas Inter-Continental Ballistic Missile (ICBM), to the Space Shuttle Main Engine (SSME).
North American Aviation (NAA) established the SSFL in 1947 in the Simi Hills of California. With the stage set for the Cold
War between the United States and the Soviet Union, the American guided missile program was well underway as soon as World
War II ended. In 1947, rocket engine development and testing focused first on the Navaho
engine, which was an adaptation of the captured German V-2 engine, and later, on the Thor and Atlas engines. Between 1954
and 1957, under contract with the US Air Force, NAA built the Alfa, Bravo, Coca and Delta test stands along with supporting
facilities and structures on land now known as Area II. The
Test Stand Activation Summary
lists the year of activation and initial program for each test stand.
In the 1960s, Area II was used for testing large liquid propulsion systems including
the F-1, J-2, H-1, and RS-27 Delta Programs. The
Area II Major Rocket Engine Programs table
provides a list of these programs and their duration. Individual engine test programs are described in greater detail in
the Test Stand & Major Rocket Engine Programs section of this page.
A liquid oxygen LOX plant was located in Area I that supplied fuel to the engine testing
being done in Area II. The plant was run by Air Products, Inc., and was one of a small
number of such facilities established during 1955-1957 by the Air Force. NASA acquired the LOX plant from the Air Force
Historical TCE Use
Kerosene-burning engines required trichloroethylene (TCE) flushing to remove the residual hydrocarbons that were combustible
and potentially explosive when exposed to LOX. The TCE fact sheet,
The Use of Trichloroethylene at
NASA’s SSFL Sites
describes TCE use at the SSFL.
After major facilities modifications during the middle and late 1970s, Coca I and IV were used for testing programs supporting the Space Shuttle Main Engine (SSME). The
first firing of a complete SSME was accomplished at Coca I on November 7, 1978.
All engine test stands at the SSFL are inactive today; the last engine test was conducted at the Alfa test area in 2006.
Several of the test stands: Alfa test stand 2, Bravo test stand 3, and Delta test stands 1, 2 and 3 as well as the LOX plant
have been dismantled.
Test Stand & Major Rocket Engine Programs
The Navaho Program was awarded to NAA by the USAF in 1946 to study supersonic missiles. The Navaho was a surface-to-surface
missile manufactured by NAA. Even though it never reached operational status before cancellation in 1957, Navaho research
development contributed to the aeronautical research program. The heavy Navaho vehicle weighed 136,000 kilograms, capable
of Mach-3 speeds, and used an improved V-2 engine, was boosted into the air by three liquid-propellant rocket engines of
135,000 pounds of thrust each. Variants of these engines were developed for Army's Redstone, Jupiter. Thor, and Atlas engines.
A mixture of LOX and jet propulsion (JP) fuel, fed the Navaho G-38 engines. Navaho engines were tested only in Area
between 1956 and 1957 at the Alfa and Coca areas. Approximately 472 tests were performed for the Navaho G-38 engine.
Although the Army had shown great initiative in ballistic missile development, the Air Force became the dominant military
service in long-range, ballistic missiles. The Air Force had the responsibility for developing the Atlas and Titan Intercontinental
Ballistic Missiles (ICBM), the Thor intermediate range missile, and later, the Minuteman, an all-solid-propellant missile.
The Atlas had a range of about 10,000 kilometers and a payload capability of 700 kilograms. The Atlas was powered by two
667-kilonewton (150,000 lb thrust) first-stage engines plus a 267-kilonewton (60,000 lb) sustainer engine. At launch, all
three engines operated and at the end of first-stage operation, the two large engines were jettisoned leaving the sustainer
engine to continue to operate during the second phase. Propellants for all three engines came from common tanks which constituted
the bulk of the structure. Since Atlas jettisoned only its first-stage engines, it was called a 1 1/2 stage vehicle.
NAA developed the Atlas propulsion system for use in the USAF’s Atlas Intercontinental Ballistic Missile Program. General
Dynamics/Convair was the lead contractor in the Atlas program with responsibilities for airframe design, assembly, and testing
of the missile system. Atlas engines used Rocket Propellant (RP)-1 for the fuel and LOX for the oxidizer as the propellant
combination. Atlas engines and thrust chambers were tested at all four Area II test
stand areas between 1955 and 1957, during the time NAA owned the property. Approximately 1,511 tests were performed for
Atlas engines and thrust chambers.
NASA joined the USAF as a sponsor of the Atlas program in 1958. Both the USAF and NASA had SSFL facilities contracts and
Atlas development production contracts with Rockwell from the 1960s through the 1980s. Test firings also were performed
under both agencies during this time. More than 75 percent of the Atlas flights were performed for the USAF. More than 7,000
tests were performed for Atlas engines and thrust chambers between 1958 and 1983 at the Area II test stands. Testing of Atlas engines and thrust chambers continued at Alfa through 2000 and at Bravo until
its closure in 2005.
The Jupiter rocket was designed and developed by the Army Ballistic Missile Agency (ABMA). ABMA launched the Jupiter-A at
Cape Canaveral, Florida, on March 1, 1957. The Jupiter vehicle was a direct derivative of the Redstone. The ABMA continued
Jupiter development into a successful intermediate ballistic missile, even though the Department of Defense directed its
operational development to the Air Force. ABMA maintained a role in Jupiter RD, including high-altitude launches that added
to ABMA's understanding of rocket vehicle operations in the near-Earth space environment. It was knowledge that paid handsome
The Jupiter Program was established by the Department of the Army in 1956 as an outgrowth of the Department of Defense’s
Intermediate Range Ballistic Missile (IRBM) Program. The propellant combination for the Jupiter engines used LOX as the
oxidizer and kerosene as the fuel. Testing and production of the Jupiter engines occurred both at SSFL and at Rocketdyne’s
Neosho, Missouri plant. Approximately 118 tests were performed for Jupiter engines at the Alfa and Delta test areas from
1957 through 1963.
Thor and RS-27 Delta Programs
During this program time, the Army continued testing its Redstones and Jupiters and a new short-range field missile called
the Pershing. The Navy was busy developing its submarine-launched Polaris missile system. The Air Force pushed ahead with
its Thor Intermediate Range Ballistic Missile (IRBM) and its Atlas, Titan and Minuteman ICBM programs. The Thor later became
the booster stage for NASA's dependable Delta launch vehicle, which has placed more satellites into orbit than any other
rocket in the nation's fold.
The Delta family of rockets have been built and launched since 1960. Its roots go back to the days immediately following
the launch of Sputnik in 1957, when the Thor was modified into a booster for Earth-orbiting satellites.
NASA's first satellite launch attempt on board Delta was Echo I in May 1960. Although it was not successful, the launch
of NASA's Echo IA satellite August 12, 1960, started Delta on its way to becoming "NASA's workhorse." Until the early 1980s
the Delta increased in size and capability, serving as NASA's primary launch vehicle for boosting communications, weather,
scientific and planetary exploration satellites into orbit.
The Thor Program was initiated in 1955 by the USAF as part of its Intermediate Range Ballistic Missile Program. Development
of the RS 27 engine began in 1971 for the Delta Program. The RS-27 engine was a hybrid of the H-1 (not tested in Area
II) rocket engine and the Thor MB-3 engine. The engines were fueled by LOX and kerosene. At least 2,262 tests were
performed for the Thor and RS-27 Delta engines at the Alfa, Bravo, and Delta test stands between 1955 and 1991. Testing
for RS-27 engines continued into 2006 at the Alfa test stands.
The E-1 engine was planned for use on launch vehicles, such as Saturn rockets. The E-1 Program was initiated in 1956 by
Rocketdyne as part of the USAF’s Rocket Engine Advancement Program. The experimental engine was a precursor to the F-1 engine.
The E-1 was the result of an effort to produce a single thrust-chamber rocket engine capable of 300,000 pounds of thrust.
Previously, this level of thrust was possible only with clusters of smaller engines. The engine was propelled by a mixture
of LOX and RP fuel. NASA sponsored approximately 24 tests performed for the E-1 thrust chamber and mainstage in 1959. Approximately
146 tests sponsored by USAF were performed for the E-1 engines and thrust chambers between 1956 and 1960. These tests were
conducted in the Bravo and Delta test areas.
X-1 and X-4 Programs
The first generation X-1 aircraft changed aviation history in numerous ways, and not simply because they were the first
aircraft to fly faster than the speed of sound. Rather, they established the concept of the research aircraft, built solely
for experimental purposes, and unhampered by any military or commercial requirements. Although subsequent X-planes were
built for a wide range of purposes - technology or concept demonstrators, unmanned test missiles, and even as prototypes
in all but name - the X-1s were built to go faster than an aircraft had ever flown before.
Capt. Charles E. "Chuck" Yeager was selected as the pilot for flights to Mach 1. He made his first glide flights on Aug.
6, 7, and 8, 1947. On Oct. 14, Yeager reached a speed of Mach 1.06 at 43,000 feet, becoming the first man to fly supersonic.
The X-1 Program for rocket powered research aircraft was established in 1956 by the USAF. The X-1 engine, similar to the
Thor and other early engines, demonstrated innovations in its ignition system and the starting sequence system that were
later applied to improved versions of both the Thor/Delta and the Atlas engines. The engine used LOX and RP-1 as propellants.
Approximately 393 tests were performed for the X-1 engine at the Delta test stands between 1958 and 1961.
The X-4 was designed to test a semi-tailless wing configuration at transonic speeds. Many engineers believed in the 1940s
that such design, without horizontal stabilizers, would avoid the interaction of shock waves between the wing and stabilizers.
These were believed to be the source of the stability problems at transonic speeds up to Mach 0.9.
The X-4 engine was an experimental version of the Atlas sustainer engine and was tested only during 1960. During that year,
approximately 12 tests were performed at the Delta test stands.
The origins of the Saturn launch vehicle concept are rooted in the research conducted within the Army Ballistic Missile
Agency in the late 1950's. A rocket engine of tremendous capabilities would be needed if man ever embarked on lunar journeys
or sent probes into deep space. As a result, development started in the 1950's on the 1.5-million-pound-thrust F-1 engine
even before a vehicle was designed for it. The F-1 would burn the familiar liquid oxygen and RP-1, and was based on an initial
concept for a 360,000-pound-thrust E-1 engine that would burn liquid oxygen and RP-1.
For a brief while, NASA considered using the F-1 on a vehicle of tremendous size, the Nova, which would be capable of direct
flights to the Moon. The Nova never materialized, but the F- 1 did and would eventually be used in the first stage of the
vehicle that would launch men on their way to the Moon. Five F-1 engines would provide a total thrust of 7.5 million pounds
in the Saturn V S-IC stage.
The F-1 Program was established in earnest at SSFL in 1959. The F-1 engines, the largest and most powerful produced in the
United States, were placed as a cluster of five at the base of a Saturn V launch vehicle. The F-1 was a liquid propelled
engine that used LOX and RP-1. The engine was too large to test at SSFL. Testing of F-1 components was performed at the
Bravo test area between 1960 and 1970.
Unless otherwise indicated, all images are provided by NASA.
External link icon This website contains links to non-NASA websites or websites that are not
under the control of NASA. These links do not constitute endorsement nor is there a guarantee of privacy or accuracy of
information. External links are denoted with this external link icon.
Adobe PDF icon
documents on this website, designated with this Adobe PDF icon or "(PDF)", require software capable of rendering PDF files
to be viewed. Adobe Acrobat Reader can be downloaded free from Adobe Systems, Inc. using the "Get Adobe Acrobat Reader" button.