Reaction Motors, Inc. (RMI) was an early American maker of liquid-fueled
rocket engines
A rocket engine is a reaction engine, producing thrust in accordance with Newton's third law by ejecting reaction mass rearward, usually a high-speed Jet (fluid), jet of high-temperature gas produced by the combustion of rocket propellants stor ...
, located in
New Jersey
New Jersey is a U.S. state, state located in both the Mid-Atlantic States, Mid-Atlantic and Northeastern United States, Northeastern regions of the United States. Located at the geographic hub of the urban area, heavily urbanized Northeas ...
. RMI engines with thrust powered the
Bell X-1 rocket aircraft that first broke the sound barrier in 1947, and later aircraft such the X-1A, X-1E, and the
Douglas D-558-2 Skyrocket. A thrust RMI engine also powered the
Viking
Vikings were seafaring people originally from Scandinavia (present-day Denmark, Norway, and Sweden),
who from the late 8th to the late 11th centuries raided, pirated, traded, and settled throughout parts of Europe.Roesdahl, pp. 9� ...
research rocket, the first large liquid-fueled US high-altitude rocket. RMI was merged with
Thiokol in 1958, where it produced the XLR-99 engine that powered the
X-15
The North American X-15 is a Hypersonic speed, hypersonic rocket-powered aircraft which was operated by the United States Air Force and the National Aeronautics and Space Administration (NASA) as part of the List of X-planes, X-plane series of ...
rocket aircraft.
History
Formation and the sound barrier
Reaction Motors, Inc. began operation as early as 1930 through the work of then
American Interplanetary Society members
Lovell Lawrence,
George Edward Pendray,
Hugh Pierce, and engineer
John Shesta. This group quickly moved from science fiction discussions to practical rocketry.
Pendray contributed heavily to their early designs using knowledge acquired from a trip to Berlin in 1931. In 1938, Princeton University student
James Hart Wyld tested a two-pound rocket engine which provided 90 pounds of thrust; this would become the basis for the group's work over the next two decades.
Though test flights are recorded from 1933 forward, the group would rename themselves the
American Rocket Society and continue experimentation in the relatively populous area of
Staten Island
Staten Island ( ) is the southernmost of the boroughs of New York City, five boroughs of New York City, coextensive with Richmond County and situated at the southernmost point of New York (state), New York. The borough is separated from the ad ...
until incorporating Reaction Motors, Inc. under Lovell Lawrence in 1938 in pursuit of a war-time contract from the United States Navy.
In 1938 and prior to incorporation, the group successfully designed and perfected the world's first workable
regenerative cooling rocket engine, technology which would for the first time make liquid-fueled rocket engines capable of burning for long enough periods to be practical. All future liquid-fueled rockets would build off this technology. They tested this rocket engine in
Pompton Lakes, New Jersey, not far from the laboratory they built it in.
Reaction Motors, Inc. (RMI) was incorporated in December 1941. It was the first commercial rocket engine company in the United States. With Lawrence as president and Wyld, Pierce, and Shesta as company officers, Reaction Motors, Inc. (RMI) received its first naval contract in 1942. Operating on a start-up budget of $5,000, the company first used a bicycle shop in
Oakland, New Jersey, belonging to Shesta's brother in-law as mailing address and laboratory but soon moved to a former night club in
Pompton Plains to provide space for rocket engine testing and machine work.
In 1945 RMI was granted a contract from the United States Army to develop a rocket engine for the first of the "X" series of experimental airplanes, designed to break the sound barrier. Undaunted by the 1946 death of British test pilot
Geoffrey de Havilland Jr., the company eventually furnished the X-1 project with a design based upon four of Wyld's engines which would provide 1,500 pounds of thrust each.
On October 14, 1947, American test pilot
Chuck Yeager
Brigadier general (United States), Brigadier General Charles Elwood Yeager ( , February 13, 1923December 7, 2020) was a United States Air Force officer, flying ace, and record-setting test pilot who in October 1947 became the first pilot in his ...
was the first in the world to break the sound barrier, piloting the X-1 with the four Reaction Motors, Inc. engines. Yeager was able to complete his flight safely due to the remarkably smooth flight provided by Wyld's system and despite the fact that he had broken several ribs while horse-riding the previous day.
Merger with Thiokol and the Space Race

In early 1956, following an extensive bidding war, Reaction Motors, Inc. was awarded a contract from the United States Navy for the development of the proposed
XLR30 engine to be used to power the experimental aircraft known as
X-15
The North American X-15 is a Hypersonic speed, hypersonic rocket-powered aircraft which was operated by the United States Air Force and the National Aeronautics and Space Administration (NASA) as part of the List of X-planes, X-plane series of ...
and eventually pursue crewed spaceflight.
After much misadventure, a massive increase in budgetary requirements, and engineering problems related to fuel injectors and the thrust chamber, which resulted in the Navy enlisting the assistance of the
Rocketdyne
Rocketdyne is an American rocket engine design and production company headquartered in Canoga Park, California, Canoga Park, in the western San Fernando Valley of suburban Los Angeles, California, Los Angeles, in southern California.
Rocketdyne ...
Division of
North American Aviation
North American Aviation (NAA) was a major American aerospace manufacturer that designed and built several notable aircraft and spacecraft. Its products included the T-6 Texan trainer, the P-51 Mustang fighter, the B-25 Mitchell bomber, the F- ...
, the XLR30 engine project was moved back on track with a new designation of
XLR-99-RM-1 to convey the striking changes in design which were required.
On April 17, 1958, RMI's acquisition by Thiokol Chemical Corporation was finalized by the approval of the stockholders and RMI was henceforth referred to as Reaction Motors Division (RMD).
RMD's
XLR99 engine for the X-15 was first flown in November 1960 and 199 flights were made before the X-15 project was discontinued in 1969, years past its due date and having cost more than five times its original budget. The X-15 is credited as having reached a record Mach 6.72 at 67 miles above the Earth, being solely responsible for providing the data necessary to insulate and maintain the structural integrity of the
Mercury spacecraft
Project Mercury was the first human spaceflight program of the United States, running from 1958 through 1963. An early highlight of the Space Race, its goal was to put a man into Earth orbital spaceflight, orbit and return him safely, ideally ...
, and a host of additional technical achievements and aviation milestones.
During this time RMD also developed the liquid engine for the
AGM-12 Bullpup missile and the
vernier engines of the
Surveyor probes.
Thiokol finally disbanded RMD in 1972.
Products
* Reaction Motors CML2N - used on
KA2N Gorgon IIA and
KA3N Gorgon III missiles
* Reaction Motors LR2-RM-2 and LR2-RM-6 - used on the
SAM-N-2 Lark missile
*
Reaction Motors XLR10 - used on
Viking (rocket)
*
Reaction Motors XLR11 - used on various vehicles, including the
Bell X-1,
Douglas D-558-2 Skyrocket, and the early
North American X-15
The North American X-15 is a Hypersonic speed, hypersonic rocket-powered aircraft which was operated by the United States Air Force and the National Aeronautics and Space Administration (NASA) as part of the List of X-planes, X-plane series of ...
rocket planes
*
Reaction Motors XLR30-RM-2 - planned for the X-15, canceled in favor of the XLR99
* Reaction Motors XLR35-RM-1 - used on the
RTV-A-2 Hiroc missile
*
Reaction Motors XLR-99 - used on the
North American X-15
The North American X-15 is a Hypersonic speed, hypersonic rocket-powered aircraft which was operated by the United States Air Force and the National Aeronautics and Space Administration (NASA) as part of the List of X-planes, X-plane series of ...
* Reaction Motors LR58-RM-4 - used on the
AGM-12 Bullpup missile
Patents filed
(partial list)
*3095694 - Reaction motor which does not require booster at high altitudes
*2637973 - "Rocket Engine Having Turbine Located in Nozzle for Driving Auxiliaries"
*2479888 - "Controlling System for Reaction Motors"
References
Further reading
*{{Cite book , last=Winter , first=Frank H. , title=America's First Rocket Company: Reaction Motors, Inc. , date=2017 , publisher=AIAA, Inc. , isbn=978-1-62410-441-1 , location=Reston, VA , doi=10.2514/4.104428
Defunct aircraft engine manufacturers of the United States
Rocket engine manufacturers of the United States