Douglas Aircraft began work on the Thor, an early Intermediate Range Ballistic Missile (IRBM), in late 1955 and put Hunter in charge of that program.
The general concept was endorsed by the Council and by High Frontier, Inc., a Washington-based group headed by Lt. Gen. Daniel O. Graham that lobbied for SDI programs.
Working together, Hunter and High Frontier convinced SDI management and other national officials that a study should be initiated to determine once and for all the feasibility of SSTO vehicles for military missions.
This led to a U.S. Department of Defense (DoD) program to design a single-stage vehicle that could replace military satellites on short notice during a national emergency.
McDonnell Douglas Corporation was contracted to build and test fly a one-third-scale, suborbital testbed called the DC-X, or Delta Clipper Experimental.
While not capable of spaceflight, the DC-X incorporated many of the technologies needed for an SSTO vehicle, including highly automated systems enabling a quick turnaround (just twenty-six hours) between launches.
In 1995, he received the Wernher von Braun Memorial Award of the National Space Society for "lifelong contributions to the fields of rockets, missiles and spaceflight.
The Space Frontier Foundation bestowed its 1994 VISION TO REALITY AWARD on Hunter and other key members of the Delta Clipper (DC-X) Team.