The development of the Super Guppy started as a solution to a transportation problem. The use of railroads to transfer oversized cargo was impossible due to the limitations of railroad tunnels, narrow roads, and low bridges. It became a larger problem when NASA entered the space race. The Pregnant Guppy was introduced in 1962 when Aero Spaceline Industries in California completed the aircraft. The aircraft was built from KC-97 Stratotanker which gave the Pregnant Guppy the largest compartment of any aircraft ever built. It was designed to carry the second stage of the Saturn rocket for the Apollo program. It took eighteen hours to transport rather than days as it would have been the Guppy.The first Guppy was so successful that retired US Air Force pilot Jack Conroy developed the Super Guppy in 1965. Compared to the Pregnant Guppy, the Super Guppy’s tail opened in order for payloads to be loaded into the cargo hold. This made operations easier. It was bigger in length and diameter. The Super Guppy remained in service for 32 years. It flew a total of three million miles for numerous space programs; this includes the Apollo and International Space Station.