A secret US space plane, an Air Force Orbital Test Vehicle known as the robotic X-37B, will return Earth this week after 22 months in orbit.
The X-37B plane is expected to land at Vandenberg Air Force Base in California, according to CNN. The unmanned craft was on a secret mission since December 2012 and racked up a record-shattering 671 days in space. There’s not much known about the mysterious spacecraft, but said Col. Keith Baits, 30th Space Wing commander, released a public statement.
“Team Vandenberg stands ready to implement safe landing operations for the X-37B Orbital Test Vehicle, the third time for this unique mission.”
The Air Force has two X-37B space planes in its fleet and has been flying them on secret missions since 2010. But the exact purpose of those flights have been shrouded in secrecy. The mission in orbit now, called Orbital Test Vehicle 3 (OTV-3), launched aboard an Atlas 5 rocket.
A notice to aviators and mariners posted on the Federal Aviation Administration’s website announced that the airspace around the Vandenberg Air Force Base would be closed between 8AM and 5 PM on Tuesday, according to Utah People’s Post.
As its name suggests, the OTV-3 mission is the third X-37B flight, but it uses the same space plane that launched on the program’s first mission, OTV-1, in April 2010. That first flight lasted 225 days. The second X-37B space plane launched in March 2011 and returned to Earth in June 2012 after 469 days in orbit.
The current OTV-3 mission for the X-37B has left the endurance milestones of the earlier missions in the dust. All X-37B missions are overseen by the U.S. Air Force Rapid Capabilities Office. The 3rd Space Experimentation Squadron at Schriever Air Force Base in Colorado Springs, Colorado, serves as mission control.
X-37B space planes resemble miniature versions of NASA’s space shuttles, just smaller, with two of the vehicles fitting inside the payload bay of a NASA shuttle. Each X-37B spacecraft is about 29 feet (8.8 meters) long and 9.5 feet (2.9 m). They have a wingspan of about 15 feet (4.6 m), and a small payload bay about the size of a pickup truck bed.
Boeing is working to repurpose a retired NASA shuttle hangar at the Kennedy Space Center in Florida, near the Cape Canaveral Air Force Station used to launch all X-37B space missions to date. Built at Boeing’s Phantom Works, the X-37B started life on drawing boards at NASA circa 1999, but the project was later transferred to the Air Force and first flew in April 2010, NPR reported.