Here he worked for the Marquardt Corporation, the aeronautical engineering firm, in the development and design of the ramjet engine for NASA  that was used on the Apollo 11 Saturn V rocket. He lost his first wife in 1966 but remarried. In 1980, Deloor returned to Belgium.
He worked at Marquardt Corporation, an aerospace engineering firm, on the development and design of the ramjet engine for NASA's Apollo 11 Saturn V rocket. He experienced a personal loss in 1966 but eventually remarried. In 1980, Deloor returned to his country of origin, Belgium.