In 1944, The U.S. Navy was in need of an antiship weapon capable of hitting outside the range of heavy antiair defenses. Engineers at Caltech designed a large caliber air launched rocket powerful enough to damage heavy shipping. It was the largest rocket in the US arsenal at the end of WWII.

Due to its large size it was given the nickname Tiny Tim.

A version can be seen at the Smithsonian Steven F. UdvarHazy Center in Chantilly VA, USA