High Quality Content by WIKIPEDIA articles! The Exploration Systems Architecture Study (ESAS) is the official title of a large-scale, system level study released by the National Aeronautics and Space Administration (NASA) in November 2005 in response to American president George W. Bush`s announcement on January 14, 2004 of his goal of returning astronauts to the Moon and eventually Mars — known as the Vision for Space Exploration (and unofficially as "Moon, Mars and Beyond" in some aerospace circles, though the specifics of a manned "beyond" programme remain vague).