During World War II the United States answered Germany's development of the V-2 with its own series of missiles. Starting in August 1944, JPL built the Private A, the first step toward an American V-2. At the Private A test site near Barstow, California, Army personnel built a rail-type missile launcher and a metal hoist frame.
The Private A was a two-stage solid fuel missile. Its booster stage included four T22 US Army Ordnance rockets delivering 21,500 pounds of thrust for 0.18 seconds. Its eight-foot long main stage burned for more than 30 seconds, delivering 1,000 pounds of thrust. In this photograph the main stage is being hoisted into the rail launcher in December 1944.
NASA
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