In the new century, the Japan Self-Defense Forces have been compelled to make significant changes in response to a rapidly changing technological environment and China's rising power. This paper investigates the opportunities for Japan in the essential sectors of military innovation, space exploitation and military satellites. It does so through a study of relevant documents pertaining to space war theories and by exploring the evolution of Japan's space strategy and active early warning capabilities through the prism of its evolving strategic needs in space, private enterprises related to that sector, and Japan's collaboration on space-based surveillance with allied nations.