Third Flight of X-37B Takes Off

Despite gloomy weather,  the Air Force launched the X-37B experimental spaceplane today (December 11).

This is the first time one of the Orbital Test Vehicles (OTVs) is making a second trip into orbit.  What these spacecraft do while in orbit is highly classified.   The first flight lasted 224 days.  The second was more than twice that long, 469 days.  How long this mission will last is not known publicly.