On the flight line

In March 2010, back before it ever flew, the X-37B posed for this picture on a runway in Titusville, Fla. During its debut orbital mission that year, the space plane traveled some 91 million miles, according to the Air Force. It's designed to operate in low Earth orbit, or between 110 and 500 miles above Earth.

A very up-to-date design, the X-37B has no hydraulics on board, according to Boeing. Instead, flight controls and brakes are activated through electromechanical means.