Summary: The National Aero-Space Plane Program, which during the past seven years has been developing an aircraft that can achieve a low earth orbit using a single stage, has been fraught with turmoil, changes in focus, and unmet expectations. The program is again at a crossroads, with costs increasing, technical progress behind schedule, and insufficient program funds. Although the program is supposed to be unconstrained by operational requirements, discussions about the utility or cost/benefit of the program have prematurely evolved into efforts to justify the program by citing the potential benefits from future operational aerospace vehicles and spin-off applications. GAO believes that, in responding to pressures to successfully compete for funding and to show results in the face of reduced budgets, unrealistic expectations have been raised about the time and cost required to achieve the program's goals and objectives. Program officials, aware of the need to again redirect the program, have proposed several alternative development strategies, but no decision has been made on which, if any, of the proposals will be approved. GAO recommends delaying any decision to build and test the X-30--a manned experimental flight vehicle--until critical technologies are developed and proven and decisions on program restructuring are made.
