This paper aims to explain what causes attempts at radical technological innovation in the military sphere to succeed or fail. Using four United States satellite reconnaissance programs as test cases, the paper also clarifies and enriches the associated historical record using recently declassified sources. Three hypotheses are derived from the military innovation and organization theory literatures: (H1) Interorganizational competition causes radical technological innovation; (H2) Radical technological innovation is the product of a permissive and stimulating organizational environment; (H3) Radical technological innovation stems primarily from requirements generated by the civilian leadership in response to external security challenges and forced upon military or intelligence organizations, which makes innovation more likely in the crucial problem areas that manage to capture the civilians’ attention. The analysis shows that a permissive organizational environment (H2) is a necessary condition for and also the most proximate cause of radical technological innovation. Furthermore, although it acted only as an intervening variable in two of the three successful programs, the third – the Navy’s GRAB signals intelligence satellite – shows that in organizations that encourage initiative, have shorter chains of command and are generally more decentralized, it is possible for a wholly internally generated drive to independently produce radical technological innovation.