Relying on undefended “exquisite” systems worked for a long time when space was a sanctuary, but our adversaries have come to recognize our dependence on these assets and are actively seeking to deny our access, making space a potential warfighting domain. In some mission areas, that means dramatically new concepts. In others, it means changes to existing systems and processes. The DOD must develop a space enterprise that is resilient, responsive, scalable, and affordable. As the DOD works to adapt and develop a new enterprise, The Aerospace Corporation is working aggressively to address all aspects of this critical challenge.