An operations based systems engineering approach for large-scale systems

NASA has not undertaken development of a large human spaceflight system since the design of the Space Shuttle System. While recent events have refocused human space flight with the goal of sending humans to Mars, the effort to synthesize a new human space flight architecture has been ongoing for the past five years. With a beginning as NASA\´s "Space Transportation Architecture Study" (STAS), through the final Orbital Space Plane (OSP) Program, the goals of human space flight have been evolving