The orbital test vehicle of the X-37B Air Force marked a new milestone on Monday.
The spacecraft, which the Air Force said was modeled after NASA's X-37 program, passed 717 days, 20 hours and 42 minutes into space the morning of August 26 – breaking the last record set by a previous mission on X-37B
The unmanned space plane is shrouded in secrecy and its missions are classified, so little is known about the work it does. According to the Air Force, the spacecraft is designed to "conduct experiments and long-range space technology testing."
Technologies tested in the program include navigation and control, thermal protection systems, avionics, light electromechanical flight systems, sophisticated materials, and autonomous orbital flight, among other things
Despite limited information, the former Secretary of the Air Force Heather Wilson told the Aspen Security Forum in July that the orbit of the vehicle was challenging opponents to find out where the spacecraft would appear next. Wilson suggested the unmanned spacecraft could modify its orbit, an ability that thwarts opponents, she said.
"We know it makes them nuts," Wilson said. "And I'm really excited about that."
Wilson's comments came shortly after pictures depicting a spacecraft in orbit were posted on Twitter on July 3 by Dutch-based astronomer Ralph Vandenberg.
NASA's X-37 program was launched for the first time. in 1
The most recent OTV mission, referred to as OTV-5, launched on September 7, 2017 by the Cape Canaveral Air Station in Florida.