In an era of declining budgets and adversaries’ evolving capabilities, quick, affordable and routine access to space is increasingly critical for national and economic security. Today’s satellite launch systems require scheduling years in advance for a limited inventory of available slots and launches often cost hundreds of millions of dollars each. The Defense Advanced Research Projects Agency created its Experimental Spaceplane, or XS-1, program to help overcome these challenges and reduce the time to get capabilities to space. DARPA artist-concept graphics