On Feb. 28, 1969, Langley Research Center issued a request for proposals to design and build the Viking Mars lander. It would land scientific payloads on Mars in 1973, gather scientific data about Martian surface features and check into the possibilities of life on Mars. The Boeing Company, the McDonnell Douglas Corp. and the Martin Marietta Corp. responded to the request for proposals. Although Martin Marietta won the contract, the Boeing effort to land the Viking contract and experience working with the Jet Propulsion Laboratory helped the company in June 1971 win the contract to build Mariner 10, with a mission to gather data from Venus and Mercury.