WASHINGTON (voa) – When NASA first conceived of the Space Shuttle, the idea was to design a rocket that could be reusable and more economical and versatile than the standard disposable stage rockets.

With SpaceX now launching its reusable Falcon 9 rocket up to several times a week, the U.S. company has quickly become a giant of global spaceflight. It's a far cry from the days of America's Space ...