Bullpup air-to-surface missile, aka, AGM-12

Developed by Martin Marietta for the US Navy.

The rocket motors were developed by Reaction Motors Inc, which merged with Thiokol in 1958.

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In the mid 1940s solid-fueled motors had problems with ambient temperatures lower than -40°F. However stored liquid fueled motors could be stored down to -65°F. At this time a number of small stored liquid fuel motors were developed. In some of these, like the one used in this missile, the fuel tanks were pressurized via burning a small solid-propellant charge.

Work on the Bullpup started in 1955. The missiles were built from 1960 to 1967. There were over 50,000 built. It holds a record for the largest number of liquid fueled motors built. It was designed to have a shelf life of five years.

For this rocket motor the oxidizer was RFNA, (Red Fuming Nitric Acid) and the fuel was a mixed amine (50.5% diethelenetriamine, 40.5% unsymmetrical dimethyl hydrizine and 9% acetonitrile). RFNA is nitric acid with dinitrogen tetroxide dissolved in it.

The general lay out was a forward annular fuel tank. With the center space taken up by the solid pressurizing propellant. The oxidizer was contained in the rear annular tank. With the center space taken up by the combustion chamber. The oxidizer flowed forward around the combustion chamber cooling it.

Two versions of this motor were built. The Bullpup A used a LR58. Which was 12.1" diameter, 40.5" long, weighed 203 lbs. And produced 12,000 lbs of thrust for 1.9 sec.

The Bullpup B used a LR62. Which was 17.3" diameter, 61.2" long, weighed 563 lbs. And produced 30,000 lbs of thrust for 2.3 sec.

By about 1960 suitable solid fuels had been developed that could tolerate low temperatures and better missiles were developed. The Bullpup was taken out of service in 1970.