Spaceflight and the use of rockets and missiles is not a uniquely American concept.  From the time that the Chinese first harnessed the power of explosive power into rockets through the dawn of the aviation age, individuals and groups throughout the world pondered on the next stage of flight.  It thus follows that the subject matter of the National Air and Space Museum encompasses not only national, but also international and multinational history. U.S. space artifacts alone do not tell the complete history of spaceflight.  The Museum’s U.S. space program collections are nearly comprehensive, illustrating programs from concept to execution, and its international collections are essential to place the National Collection into the proper context.