The main purpose of this study is to analyse the reason for approving the Dyna-Soar Project of the U.S. Air Force during the Eisenhower Administration, based on declassified archival sources. The Aggressive nature of the Dyna-Soar Project could not consist with a peaceful keynote of the Eisenhower Administration’s space policy. The main goals of the Eisenhower Administration were to deter an arms race with the Soviet Union and to relieve a pressure on a national defence budget. All those aims could be achieved by emphasizing a peaceful use of outer space that guaranteed a safety and a legitimacy of using the US reconnaissance satellites in outer space. However, the Dyna-Soar Project of the US Air Force aimed to develop offensive space technologies and, accordingly, to secure increased defence budget. This study argues that the US Air Force had an organizational culture perceiving an outer space as an area for military operations, that, by the reason, the US Air Force had already developed a preceding research of the Dyna-Soar Project, that the US Air Force used an approach to relieve anxiety about offensive nature of the project by dividing it into several stages, that they highlighted economic efficiency of the project by connecting it to other three different space missions, and that, aside through aforementioned steps, the US Air Force could have an official approval to the project by taking advantage of pervasive anxiety of the Congress, a public, and a mass media over a success of the Sputnik by the Soviet Union.