Florida Space Center Home to Secret Spacecraft

Kennedy Space Center will be the testing site for a top-secret Air Force space plane.

Boeing is working on the spacecraft, and the company announced Friday that it will convert a former space shuttle building for the X-37B orbital test vehicle program.

An undisclosed number of workers will recover, refurbish and relaunch the 29-foot(8.8-meter)-long unmanned spacecraft.

The Air Force launched the most recent flight of the unmanned spacecraft from Florida's Space Coast more than a year ago.

It was the second flight for the original X-37B space plane. The craft circled the planet for seven months in 2010. A second X-37B spacecraft spent more than a year in orbit.

The mystery machines are about one-quarter the size of NASA's old space shuttles and can land automatically on a runway.