The end of the spacecraft's current mission was marked by a series of sonic booms over Florida on Saturday.
The latest mission of the mysterious space plane has so far lasted 500 days and nobody knows what it's up to.
The US military's secretive space plane is due to launch on May 16th with a cargo full of experiments.
The US military's notoriously secretive miniature space shuttle is back and nobody knows what it has been up to.
The US military's secretive pint-sized spacecraft has now spent a whopping 717 days up in space non-stop.
For the first time, someone has managed to snap an image of the enigmatic mini-shuttle in Earth's orbit.
The US military's mysterious X-37B has spent almost a year in space on its latest secretive mission.
The mysterious unmanned shuttle has embarked on yet another mission that nobody knows anything about.
The US Air Force's mysterious space plane has landed in Florida after spending nearly two years in orbit.
The US Air Force's mysterious space plane is on track to break the mission duration record of 674 days.
The X-37B will be launching again on Wednesday however nobody knows exactly what it will be doing.
The secretive aircraft will be landing in California after being on a mission that lasted two years.
The US Air Force's enigmatic space plane, the X-37B, has embarked on its third mysterious mission.
The mysterious aircraft will be heading off in to the skies once again on another undetermined mission.
The experimental US Air Force X-37B space plane was supposed to land in December after nine months.
Sky watchers have determined that the secretive X-37B which launched last month went up to test a new spy satellite.