Aero Spacelines, Inc. is an American aircraft manufacturer which made a name for itself by converting Boeing 377 Stratocruisers into the famous Guppy line of airplanes, re-engineered solely for transporting oversized cargo such as space exploration vehicles.
Aero Spacelines was formed with only one customer in mind. NASA required a way to transport outsized cargo from their suppliers' manufacturing plants to Cape Canaveral Air Force Station in Florida. Their freight shipments were too large to be safely transported by rail or truck; shipping by sea was time consuming, expensive, and fraught with the danger of damaging the shipments on turbulent seas. The only viable means of transporting NASA's cargo was by air. However, due to the large size of the components, no existing aircraft was capable of accomplishing the task.
John M. "Jack" Conroy, an ex-United States Air Force pilot, and Lee Mansdorf, an aircraft salesman and entrepreneur, formulated the Guppy concept one evening over dinner. It was decided a company needed to be established to manufacture outsized aircraft. Conroy hired Robert W. Lillibridge as Vice President-Manufacturing and Engineering, and assembled a team for the project. Financing was provided by venture capitalist William Ballon, a World War II combat veteran from the Army Air Corps. Once the company was established at Van Nuys Airport, California, Aero Spacelines began in 1960 to engineer the transformation of the Boeing 377 airliner into the Pregnant Guppy.
Among the earliest of NASA's shipments utilizing the Pregnant Guppy were the first and second stages of the Gemini Program's Titan II GVL from the Martin Co. in Baltimore, Maryland, to Cape Canaveral, Florida. Subsequent versions of the Guppy series transported the S-IVB, the third stage of the Saturn booster from California to Florida.
In 1967, Aero Spacelines encountered financial difficulties and was acquired by Unexcelled Inc. That corporation was sold to Tracor Aviation. Jack Conroy organized a new company, Conroy Aircraft, which built more airplanes for transporting oversized cargo. By November 1968, NASA had paid Aero Spacelines $11,591,633 in contracts. Conroy ceased operations in 1972.