WASHINGTON — A U.S. Air Force X-37B spaceplane made a pre-dawn landing Oct. 27 at NASA’s Kennedy Space Center in Florida, after spending 780 days in orbit, breaking its own record by 62 days.

The Air Force said the  X-37B Orbital Test Vehicle-5  (OTV-5) mission officially ended at 3:51 a.m. Eastern with a successful runway landing at NASA’s Shuttle Landing Facility. The mission originally launched on a SpaceX Falcon 9 rocket Sept. 7, 2017.

The Boeing-built X-37B  that landed Oct. 27 is one of at least two such autonomous spaceplanes in the Air Force’s fleet. First launched in 2010, the reusable X-37Bs have accumulated 2,856 days in orbit. The spaceplane originally was designed to fly for just 270 days.

“The X-37B continues to demonstrate the importance of a reusable spaceplane,” Air Force Secretary Barbara Barrett said in a news release.

The spaceplane program, managed by the Air Force Rapid Capabilities Office, has been used for science experiments to test technologies in a long-duration space environment.

“With a successful landing today, the X-37B completed its longest flight to date and successfully completed all mission objectives,” said Randy Walden, director of the Air Force Rapid Capabilities Office. “This mission successfully hosted Air Force Research Laboratory experiments, among others, as well as providing a ride for small satellites.”

One of the experiments on OTV-5 is the U.S. Air Force Research Laboratory’s second Advanced Structurally Embedded Thermal Spreader (ASETS-II). This experiment will measure the long term performance of an oscillating heat pipe on orbit. Oscillating heat pipes are capable of transporting more than 45 times more heat than copper and are one of many technologies that the Air Force is testing to help advance space vehicle designs, AFRL said.

The original X-37 program was led by NASA and ran from 1999 to 2004, when the Defense Advanced Research Projects Agency took possession of the X-37A vehicle and conducted a series of approach and landing tests over the next two years. In 2006, the Air Force tapped Boeing to build the follow-on X-37B. A second X-37B was built in 2010.

The Oct. 27 landing marked the second time an X-37B touched down at Kennedy Space Center’s Shuttle Landing Facility. The first was OTV-4, which landed May 7, 2017, after  718 days in orbit. The first three X-37B missions landed at Vandenberg Air Force Base, California.

The Air Force plans to launch the sixth X-37B mission from Cape Canaveral in 2020 on a United Launch Alliance Atlas 5 rocket. The Air Force Space and Missile Systems Center expects to launch to occur sometime between April and June.

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...