America’s first reusable unmanned spaceplane, the X-37B, made its inaugural trip to orbit in April, completing more than a decade of work by NASA and the U.S. Department of Defense. The mission is classified.
The X-37B looks and behaves like a shrunken space shuttle, right down to its method of reentry; once it completes its mission, it will glide back to Earth and land on a runway in California. But we do know that this kind of unmanned mini shuttle is attractive for many reasons.
Because it’s smaller and doesn’t carry humans, it’s cheaper and simpler to launch. It can be reused repeatedly to ferry satellites to orbit in its payload bay. Soon after launch, amateur astronomers spotted the plane in an orbit used by observation satellites.