The evolution of Marquardt can be summed up as follows: in the early 1950's, they begin testing and manufacturing ramjets in Van Nuys, CA., highlighting the supersonic RJ43-MA-11.

-They build ram-jets until the early 1960’s. Then the construction of thrusters for the Apollo Moon Module begins.

-They used the R4-D in clusters of four for maneuvering. For that and other projects such as the Space Shuttle Orbiter, Marquardt made the R40-A and R-1A.

-In 1983 it is acquired by ISC Defense and Space Group. In 1987 it is bought by the Scottish Ferranti.

-And in 1991 after another crisis it is divided in two: the part in Van Nuys goes to Kaiser while the other part -no propulsion- disappears.

-Later the Van Nuys propulsion part goes to Primex-Technologies, in the year 2000.

“Kaiser-Marquardt thruster” (PiP)

-The main Thrusters used for the control of space vehicles are the following:

-The R-1E, from 1981 for the Columbia, of the vernier type to adjust orbits.

-It uses nitrogen tetroxide and monomethyl hydrazine with a thrust of 110 Newtons.

-The R-4D on the Apollo 201 in 1966. With the same hypergolic fuel: nitrogen tetroxide and MMH or hydrazine. It delivered 490 N in vacuum for 312 seconds.

-The R-6C was used on communications satellites, with 22 to 100 N of thrust depending on the series. It used the same above mentioned fuels.

-The R-40A was destined for the Shuttle Orbiter with the same fuel and a thrust of 3,870 N for 281 seconds.

-The Thruster of the photograph delivers 100 N for 322 seconds.

-Another series consists of monopropellant thrusters using catalytic hydrazine. The company acquired this engine line from United Technologies (UTC) of the Hamilton Standard Div.

-Outstanding are:
-REA 10, with 0.89 N.
-REA 17-6, with 2.22 N.
-REA 17-12, with 4.45 N.
-REA 16, with 22.2 N the same as the REA 39-2.
-REA 22-5, with 53.4 N.
-REA 22-2, de 91.6 N.
-REA 22-16, with 133.4 N.
-REA 22-17, with 177.9 N.
-REA 20-4, with 556 N.

-As we see, the above mentioned engines can be considered medium thrust. There are many proposed projects such as the “Ascent Stage” program.