On Thursday, SpaceX is scheduled to launch a communications satellite from the Kennedy Space Center in Florida using a rocket stage that has already been to space and back. SpaceX is betting that this kind of recycled rocket will soon lower its costs and revolutionize space flight.

At the moment, the aerospace industry essentially throws away its hefty rockets. Partway into orbit, the big, expensive first stage falls off and plunges back to earth.

It's a unique business model within the transportation sector, says Bobby Braun, the dean of the College of Engineering and Science at the University of Colorado Boulder. He says to see how strange it is, imagine flying from Denver to Washington, D.C.: "When I got there, the airline wouldn't throw away that airplane and put me on a new one to bring me back a few days later," he says.