Aerojet is a major rocket engine manufacturer based primarily in Sacramento, California. Their products include a wide range of engines, from main engines used on a number of NASA vehicles and ballistic missiles, down to stationkeeping thrusters for spacecraft. Aerojet is one of only a very small number of companies that was dedicated almost entirely to rocket engines, the other being their rivals at Rocketdyne. Other divisions produce chemicals at an industrial scale, ordinance for the various branches of the US military, and various space-related sensors and electronics.

Aerojet developed from a 1936 meeting hosted by Theodore von Karman at his house. Attending were a number of other CalTech professors and students, as well as self-taught rocketry experts Jack Parsons and Ed Forman , all of whom were interested in the topic of space flight. The group continued to meet time to time, but was essentially limited to discussions as opposed to experimentation. Things changed in 1938 when the US Army offered two research projects, one for windshield de-icing on aircraft, and another for rocket engines to launch aircraft (today known as JATO). Dr. Jerome Hunsaker at MIT had the first pick, and feeling that the rocket research was a "Buck Rogers" project, left rockets to the CalTech team.

Their first design was tested on August 16, 1941, consisting of a small cylindrical solid fuel motor attached to the bottom of a plane. The takeoff distance was shortened by half, and the USAAC placed an order for experimental production versions. On March 19, 1942 the company was officially formed in Azusa, CA, known as Aerojet Engineering. In 1943 the Air Corps finally placed a full order, demanding that 2000 be delivered before year-end. The company also invested in pure rocket research, developing both a liquid fueled design, and a new solid fuel design based on a rubber binding agent in partnership with General Tire . In the immediate post-war era Aerojet downsized dramatically, but their JATO units continued to sell for commercial aircraft operating in hot-and-high conditions.

By 1950 their research into the rubber-binder had led to much larger engines, and then to the development of the Aerobee sounding rocket. Aerobee was the first US designed rocket to reach space (albeit not orbit), and completed over 1000 flights before it was retired in 1985. The newly-formed US Air Force used Aerojet as the primary supplier on a number of their ICBM projects, including the Titan and Minuteman missiles. They also delivered propulsion systems for the US Navy's submarine-launched Polaris missile. A new plant was set up in Sacremento that took over most rocket construction, while the original Azusa offices returned primarily to research. One of Azusa's major projects was the development of the infra-red detectors for the Defense Support Program satellites, used to detect ICBM launches from space. The new research arm was formed as Aerojet Electronics, and after purchasing a number of ordinance companies, Aerojet Ordinance was created as well. A new umbrella organization oversaw the three major divisions, Aerojet General.

President Kennedy's challenge to place man on the Moon by the end of the 1960s led to increased civilian work at Aerojet. In the past they had repeatedly lost contracts for large engines for the Saturn and Nova boosters, being designed in the late 1950s, typically to their rival Rocketdyne, but in the end were selected to develop and build the main engine for the Apollo Command/Service Module. In 1962 they were also selected to design a new upper-stage engine to replace the cluster of four J-2s used on the Saturn second stage in the post-Apollo era, but work on their resulting M-1 design was later ended in 1965 when it became clear the public's support for a massive space program was waning.

The 1960s were also marked by an increased demand for various ordinance for the Vietnam War, which Aerojet had branched into in the late 1950s. Similar work continued in the 1970s, delivering the 2nd stage motor for the MX missile, the thruster systems for the Space Shuttle, and the first US-designed cluster bombs. A contract for 30mm ammunition for the A-10 Thunderbolt II was so extensive that new branch plants were set up in Downey and Chino in 1978. Aerojet also purchased a number of other firms over this period, and their plant in Jonesborough, TN developed the use of depleted uranium ordinance. To this day they are the primary supplier of these weapons. Their electronics and ordinance divisions also collaborated on the SADARM 8" anti-armor artillery round, but this was not put into production.

The 1980s saw a brief revival of the aerospace business during the heyday of Regan's SDI program, but the company shrank continually during the late 1980s and into the 1990s. Today they are organized under the umbrella company GenCorp, and one of GenCorp's major "products" is the sell-off of land at the Sacremento plant for housing development. The company's huge chemical processing capabilities, originally used for making fuel, are also being offered to the pharmaceutical industry under the name Aerojet Fine Chemicals.

External links

• Aerojet corporation
• GenCorp web site