A mystery space mission right over your head
A super-secret spacecraft has been orbiting the earth for more than 500 days. No one will tell us what it's doing up there, how long it's staying up, or where it's going to land.
The plot of a science fiction thriller? Nope.
The Air Force's unmanned X-37B space plane is on its fourth secret mission which has recently passed the 500-day mark. (The third mi…
