Gemini was robust enough that the United States Air Force planned to use it for the Manned Orbital Laboratory (MOL) program, which was later canceled. Gemini's chief designer, Jim Chamberlin, also made detailed plans for cislunar and lunar landing missions in late 1961. He believed Gemini spacecraft could fly in lunar operations before Project Apollo, and cost less. NASA's administration did not approve those plans. In 1969, McDonnell-Douglas proposed a "Big Gemini" that could have been used to shuttle up to 12 astronauts to the planned space stations in the Apollo Applications Project (AAP). The only AAP project funded was Skylab – which used existing spacecraft and hardware – thereby eliminating the need for Big Gemini.