The 780-day mission sets a new endurance record for the reusable test vehicle.
Residents along the Space Coast may have heard a loud boom early Sunday as the U.S. Air Force's secretive, uncrewed X-37B spaceplane returned to Kennedy Space Center after almost two years in orbit, News 6 partner Florida Today reports.
The big picture: The Air Force's unmanned spaceplane has returned to Earth following a record 780 days in orbit.
During the aircraft's previous missions, amateur astronomers were able to detect the orbital pattern of the first X-37B which included flyovers of North Korea, Iraq, Iran, Pakistan and Afghanistan, heightening the suspicion that the vehicle was being used for surveillance.
The Air Force announced the unmanned X-37B Orbital Test Vehicle landed at NASA's Kennedy Space Center Shuttle Land Facility on 27 October at 3:51 a.m. As of today, the total number of days spent on-orbit for the entire test vehicle program is 2,865 days, the Air Force said.
The X-37B resembles NASA's space shuttle, but at less than 10 meters in length it is considerably smaller.
The sixth X-37B mission is in the works, and it will launch on top a Space X Falcon 9 booster at an undetermined date.
As ever, the biggest question surrounding the Air Force's space plane concerned what it was up to during its long flight in low-Earth orbit. That spacecraft, scaled down from the X-40 model, was not created to go into space but rather to test unmanned, autonomous landing hardware and software.
The X-37B continues to demonstrate the importance of a reusable spaceplane'.
A recent statement from the Air Force claims it is simply performing "risk reduction, experimentation and concept of operations" for reusable spacecraft technology; previous announcements have described tests for navigation and control, thermal protection systems, avionics, advanced propulsion systems, reentry and landing. The fifth mission launched in September of 2017.
The solar-powered spaceplane was created to spend 270 days in orbit, according to the Air Force.
The spacecraft completed "all mission objectives", according to USAF Rapid Capabilities Office director Randy Walden.
The Pentagon, increasingly reliant on space technologies, recently created the US Space Command and is asking Congress to approve funding for a proposed Space Force, which would serve as a new branch of the military.