U.S. military space plane lands, ending record-breaking mission

The robotic X-37B Orbital Test Vehicle-6 touched down at NASA's Kennedy Space Center in Florida at 5:22 a.m. The 908 days in orbit was four months longer than any previous X-37B flight.

The plane, which was built by Boeing, also carried a service module for the first time.

"With the service module added, this was the most we've ever carried to orbit on the X-37B, and we're proud to have been able to prove out this new and flexible capability for the government and its industry partners," Jim Chilton, senior vice president at Boeing Space and Launch, said in a statement.

The OTV-6 mission hosted the Naval Research Laboratory's Photovoltaic Radiofrequency Antenna Module, which was able to harness solar rays outside of Earth's atmosphere and transmit power to the ground, the U.S. Space Force said in a statement.

"The X-37B continues to push the boundaries of experimentation, enabled by an elite government and industry team behind the scenes," Lt. Col. Joseph Fritschen, X-37B program director, said in a statement. "The ability to conduct on-orbit experiments and bring them home safely for in-depth analysis on the ground has proven valuable for the Department of the Air Force and scientific community."

According to Space.com, while OTV-6 set a new mission-duration record for the X-37B program, it didn't come close to the overall spaceflight mark.

The International Space Station has been continuously occupied by rotating astronaut crews since November 2000, and NASA's Voyager 1 and Voyager 2 probes remain operational in interstellar space more than 45 years after lifting off.