Marquardt Corporation was one of the few aeronautical engineering firms that was dedicated almost solely to the development of the ramjet
A ramjet, sometimes referred to as a stovepipe jet, or an athodyd, is a form of airbreathing jet engine using the engine's forward motion to compress incoming air, without a rotary compressor. Ramjets cannot produce thrust at zero airspeed and thus cannot move an aircraft from a standstill...

 engine. Marquardt designs were developed through the 1940s into the 1960s, but the ramjet never became a major design and the company turned to other fields in the 1970s. They suffered a particularly bad financial crisis with the ending of the Cold War
Cold War
The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

, and went bankrupt in the 1990s.


Roy Marquardt was an aeronautical engineering graduate from Caltech who had worked at Northrop
Northrop Corporation
Northrop Corporation was a leading United States aircraft manufacturer from its formation in 1939 until its merger with Grumman to form Northrop Grumman in 1994. The company is known for its development of the flying wing design, although only a few of these have entered service.-History:Jack...

 during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 on the YB-35
Northrop YB-35
The Northrop XB-35 and YB-35 were experimental heavy bomber aircraft developed for the United States Army Air Forces during and shortly after World War II by the Northrop Corporation. It used the radical and potentially very efficient flying wing design, in which the tail section and fuselage are...

 flying-wing bomber project. While working on problems cooling the engines, which were buried in the wings, he found that the heat generated by the engines produced useful thrust. This started his interest in the ramjet principle, and in November 1944 he started Marquardt Aircraft in Venice, California to develop and sell ramjet engines. In the late 1940s the company relocated to Van Nuys, California, adjacent to the Van Nuys Airport
Van Nuys Airport
Van Nuys Airport is a public airport located in Van Nuys in the San Fernando Valley section of the city limits of Los Angeles, California, United States. No major commercial airlines fly into this airport; it is used by private, chartered, and small commercial aircraft...


Marquardt's first products were wind tunnels, but by the end of their first year they had delivered an experimental 20 inch (0.51 m) ramjet to the United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...

 for testing. The United States Army Air Forces
United States Army Air Forces
The United States Army Air Forces was the military aviation arm of the United States of America during and immediately after World War II, and the direct predecessor of the United States Air Force....

 purchased two of the same design early in 1946, and fitted them to the wingtips of a P-51 Mustang
P-51 Mustang
The North American Aviation P-51 Mustang was an American long-range, single-seat fighter and fighter-bomber used during World War II, the Korean War and in several other conflicts...

 fighter for in-flight testing. By this time the Navy had fitted theirs to a F7F Tigercat
F7F Tigercat
The Grumman F7F Tigercat was the first twin-engined fighter aircraft to enter service with the United States Navy. Designed for the new Midway-class aircraft carriers, the aircraft were too large to operate from earlier decks. Although delivered to United States Marine Corps combat units before...

 and started flight tests in late 1946. Later Navy tests fitted the same engine to a XP-83 and F-82 Twin Mustang
F-82 Twin Mustang
The North American F-82 Twin Mustang was the last American piston-engine fighter ordered into production by the United States Air Force. Based on the P-51 Mustang, the F-82 was originally designed as a long-range escort fighter in World War II; however, the war ended well before the first...


In 1947 Martin
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...

 built the Gorgon IV missile testbed, powered by the 20" engine. Four Gorgon flights with the new engines were made that year at Mach 0.85 at 10,000 feet (3,000 m) altitude, and in 1948 a newer engine pushed the speeds to Mach 0.9. Martin eventually won a contract to convert the Gorgon design into a target drone, becoming the KDM-1 Plover, and delivering Marquardt a contract for 600 more 20" engines.

In 1948 the newly created United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

 took delivery of several larger 30" (0.76 m) designs and fitted them to the wingtips of a P-80 Shooting Star
P-80 Shooting Star
The Lockheed P-80 Shooting Star was the first jet fighter used operationally by the United States Army Air Forces. Designed in 1943 as a response to the German Messerschmitt Me-262 jet fighter, and delivered in just 143 days from the start of the design process, production models were flying but...

, which became the first manned aircraft to be powered by ramjets alone. An even larger 48" (1.22 m) design was built as a booster for a new interceptor design, but not put into production.

The same year the company also started conversion of the existing engine designs to operate at supersonic
Supersonic speed is a rate of travel of an object that exceeds the speed of sound . For objects traveling in dry air of a temperature of 20 °C this speed is approximately 343 m/s, 1,125 ft/s, 768 mph or 1,235 km/h. Speeds greater than five times the speed of sound are often...

 speeds. This requires the airflow to be slowed to subsonic speeds for combustion, which is accomplished with a series of shock wave
Shock wave
A shock wave is a type of propagating disturbance. Like an ordinary wave, it carries energy and can propagate through a medium or in some cases in the absence of a material medium, through a field such as the electromagnetic field...

s created by a carefully designed inlet. Starting with the existing 20" design from 1947, work progressed until the new engine was ready for use in 1949.

By this point the company had outgrown its Venice plant, but was unable to fund a larger factory. Marquardt sold a controlling interest in the company to General Tire and Rubber Company in 1949, and used the funds to move to a new site in Van Nuys, the former Timm Aircraft factories. The purchase wasn't a happy one for General Tire due to management differences, after making "only" 25% return in one year, they agreed to sell their share of the company to another investor. Eventually such an investor was found, and General Tire sold their stake to Laurance Rockefeller
Laurance Rockefeller
Laurance Spelman Rockefeller was a venture capitalist, financier, philanthropist, a major conservationist and a prominent third-generation member of the Rockefeller family. He was the fourth child of John D. Rockefeller, Jr. and brother to John D...

 in 1950 for $250,000.

In the early 1950s supersonic cruise missile
Cruise missile
A cruise missile is a guided missile that carries an explosive payload and is propelled, usually by a jet engine, towards a land-based or sea-based target. Cruise missiles are designed to deliver a large warhead over long distances with high accuracy...

 and target drone projects for various roles were quite common. Many of them were designs to be shot down as target drones, or simply crash or explode at the end of their mission, so simplicity and low cost was as important as high-speed performance. This made the ramjet ideally suited to these roles. By 1952 Marquardt was involved in a number of projects, including the Navy's Rigel missile, and the Air Force's CIM-10 Bomarc anti-aircraft missile. To test the new engine design for the Bomarc, the X-7 high-speed radio control
Radio control
Radio control is the use of radio signals to remotely control a device. The term is used frequently to refer to the control of model vehicles from a hand-held radio transmitter...

 test aircraft was built.

Over the next few years the X-7 missile broke many records, and led the Air Force to award Marquardt the contract for the BOMARC missile engines. Originally they had intended to award the production to a larger company with better manufacturing abilities, as the Van Nuys plant wouldn't be able to build the 1,500 engines quickly enough. Instead, the Air Force and Marquardt collaborated on a new plant on the shores of Great Salt Lake
Great Salt Lake
The Great Salt Lake, located in the northern part of the U.S. state of Utah, is the largest salt water lake in the western hemisphere, the fourth-largest terminal lake in the world. In an average year the lake covers an area of around , but the lake's size fluctuates substantially due to its...

 just outside of Ogden, Utah
Ogden, Utah
Ogden is a city in Weber County, Utah, United States. Ogden serves as the county seat of Weber County. The population was 82,825 according to the 2010 Census. The city served as a major railway hub through much of its history, and still handles a great deal of freight rail traffic which makes it a...

. The plant opened in June 1957, and delivered their first engines a month ahead of schedule. By 1958 the engine was in full production, leading to an additional engine contract from the Air Force for an equally large run of a more advanced version for the IM-99B "Super BOMARC". Meanwhile the X-7 continued to break records, eventually setting the speed record for air-breathing vehicles at Mach 4.31.

By 1959 the company had sales of $70 million, and had purchased several smaller aerospace firms. One of these purchases, Power Systems, led to a number of designs for small rocket motors used as positioning thrusters. This would eventually become one of Marquardt biggest product lines in the 1960s. Meanwhile the main Van Nuys plant was also involved in research into new systems, including a nuclear-powered ramjet for Project Pluto
Project Pluto
Project Pluto was a United States government program to develop nuclear powered ramjet engines for use in cruise missiles. Two experimental engines were tested at the United States Department of Energy Nevada Test Site in 1961 and 1964.-History:...

 and a liquid air cycle engine
Liquid air cycle engine
A Liquid Air Cycle Engine is a type of spacecraft propulsion engine that attempts to increase its efficiency by gathering part of its oxidizer from the atmosphere...

 (LACE) for the Air Force's Aerospaceplane
The US Air Force's aerospaceplane project encompassed a variety of projects from 1958 until 1963 to study a fully reusable spaceplane. A variety of designs were studied during the lifetime of the project, including most of the early efforts on liquid air cycle engines and even a nuclear-powered...

 efforts. Another new product line started with the introduction of their first ram-air turbine, small air-powered generators for providing aircraft with electric power if the main engine failed. With this diversification came a name change, to Marquardt Corporation.

By 1970 Marquardt was known primarily as "the" company for small rocket engines and thrusters. Practically all US space vehicles and satellites used their designs, eventually including a major win for the Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...

 program. The company developed and provided the 25 and 870 lb. trusters for the space shuttle.

The market for ramjet engines had largely disappeared by this point due to increased performance from turbojet engines, but Marquardt continued low-level development on advanced designs. One system, developed in partnership with Morton Thiokol
Thiokol is a U.S. corporation concerned initially with rubber and related chemicals, and later with rocket and missile propulsion systems...

, placed a solid fuel
Solid fuel
Solid fuel refers to various types of solid material that are used as fuel to produce energy and provide heating, usually released through combustion....

 booster inside the ramjet core. When the solid fuel burned out the ramjet would ignite as normal. The idea was to combine the booster and ramjet into a single airframe, thereby reducing cost, size, and range safety requirements, as nothing would be jettisoned in flight.

In 1983 the company was purchased by the ISC Defense and Space Group International Signal and Control
International Signal and Control
International Signal and Control was a U.S. defense contractor based in Lancaster, Pennsylvania that was involved in the manufacture of electronic missile subassemblies, navigation components, fuses, power supplies for proximity fuzes, and grenade technology.By the 1980s, ISC's business primarily...

. In 1987, ISC was purchased by British-based Ferranti
Ferranti or Ferranti International plc was a UK electrical engineering and equipment firm that operated for over a century from 1885 until it went bankrupt in 1993. Known primarily for defence electronics, the Company was once a constituent of the FTSE 100 Index but ceased trading in 1993.The...

. Ferranti declared bankruptcy
Bankruptcy is a legal status of an insolvent person or an organisation, that is, one that cannot repay the debts owed to creditors. In most jurisdictions bankruptcy is imposed by a court order, often initiated by the debtor....

 in 1991, and Marquardt was split in two. The Marquardt Jet Laboratory, building rocket thrusters, was sold to Kaiser Aerospace, while the Marquardt Manufacturing Company disappeared. Kaiser reportedly picked up Marquardt for a mere $1 million, with about $50 million in outstanding Space Shuttle contracts. Kaiser closed the Van Nuys plant in 2001.


  • Marquardt RJ30
  • Marquardt RJ31
  • Marquardt RJ34
  • Marquardt RJ39
  • Marquardt RJ43
    Marquardt RJ43
    The Marquardt RJ43-MA were ramjet engines used on the CIM-10 Bomarc missile and on the D-21 drone. They were engineered and built by the Marquardt Corporation.*Thrust:...

  • Marquardt RJ57
  • Marquardt RJ59


  • Marquardt Space Sled
    Marquardt Space Sled
    The Marquardt Space Sled was developed by the Marquardt Corporation in the 1960s as part of an effort to build a device that would allow astronauts to maneuver freely in space without needing to be tethered to their spacecraft or stations....

  • Marquardt 100 lbf (444.8 N) thrust reaction control engines were used on both the moon lander and the command module on all the manned moon flights.
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