Constellation program´s stretch goal requirements

In 2004, the Vision for Space Exploration (VSE) was announced by the United States President´s Administration in an effort to explore space and to extend a human presence across our solar system. Subsequently, NASA established the Exploration Systems Mission Directorate (ESMD) to develop a constellation of new capabilities, supporting technologies, and foundational research that allows for the sustained and affordable exploration of space. Then, ESMD specified the primary mission for the constellation program (CxP)-to carry out a series of human expeditions, ranging from low earth orbit (LEO) to the surface of Mars and beyond for the purposes of conducting human exploration of space. The CxP was established at the Lyndon B. Johnson Space Center (JSC) to manage the development of the flight and ground infrastructure and systems that require enabling continued and extended human access to space.