"The Defense Space Strategy is the next step to ensure space superiority and to secure the Nation's vital interests in space now and in the future." -Secretary of Defense, Mark T. Esper (2020) Defense Space Strategy (2020), released by the US Department of Defense, shows how the Department of Defense will advance space power to be able to compete, deter, and win in a complex and competitive security environment. This strategy summary explains its objectives for the next ten years: - to build a comprehensive military advantage in space; - to integrate space into national, joint, and combined operations; - to shape the strategic environment; and - to cooperate with allies, partners, industry, and other US Government departments and agencies. Students of national security, journalists and anyone interested in the future of defense space strategy, will need to read this publication.