U.S. Air Force mini shuttle back in orbit for secret mission.
The Air Force launched its unmanned mini-shuttle from Cape Canaveral, Florida, late Wednesday morning. An Atlas V rocket carried it up.
This is the fourth flight for the military research program, which is shrouded in secrecy. The last X-37B mission lasted close to 675 days and ended with a California touchdown. The Air Force won’t say how long this particular mission will last or where it will end.
The X-37B looks like a miniature version of a NASA space shuttle. Like the old shuttle, the X-37B launches vertically and lands horizontally, is reusable, and has lots of room for experiments. But no one flies on them; they are operated robotically.