This thesis develops a compelling case for a national space vision to advance the American vital interests of prosperity and security. The first half of paper focuses on laying the background for the vision that follows in the second half. In the title, prosperity is listed before security since it is the reason for exploration and eventually requires protection. The paper begins with the premise that space is becoming an information center of gravity that is increasingly important to the commercial sector as well as the military. However, a major stumbling block in this transition is the lack of the means to protect on-orbit space systems. Without this capability, true command of space is not possible. The paper then transitions to a discourse on the current dependence on space in America. Next, the quest for wealth and information by the European powers in the second millennium is discussed. Each of these examples demonstrates a recurring cycle in their quest: knowledge, exploitation, investment, consumption and protection. This same cycle is seen in the early days of space where the focus was almost exclusively on knowledge and exploration. Several who possessed a vision to advance space were Jules Verne, Wernher von Braun and Arthur C. Clark. From the early days of space, the transition is made to reviewing a current space system, Global Positioning System, as an example of the promise of space and the current focus on investment and consumption. To make the case for protecting space assets, the role of the U.S. Navy in protecting maritime commerce is examined as well as the current threat to the space sector. The vision for space focuses on the near-term and primarily on the Air Force. While it is recognized that space is much larger, consisting of the military, intelligence, civil and commercial sectors, to thoroughly discuss each sector is beyond the scope of this paper. The Air Force is singled out since it controls nearly ninety percent of the DOD's white-world space budget and contains nearly the same percentage of space personnel. Fundamental changes are recommended in each of these areas: organization, space doctrine, changing the space culture, professional military education, funding/core competencies, and a review of whether to integrate or separate space capabilities. In addition to these, recommendations are also made for the president and Congress to advance toward the goal of commanding space. The future requires a national effort to master all sectors of space for America to realize its vital interests of prosperity and security. The vision--to command space--is an economic and political imperative, which in turn will require a military capability. It is a matter of quality of life as well as national security.