Only the US Air Force knows why a mysterious spacecraft has been orbiting the earth for the last 720 days. The Orbital Test Vehicle 5 (OTV-5) mission was launched in September 2017 with the help of SpaceX Falcon 9 rocket. This is the fifth mission of the X-37B spacecraft, an unaltered and solar-powered military drone. In the fourth mission – Orbital Test Vehicle 4 (OTV-4) – it will be in orbit for 717 days, 20 hours, 42 minutes, which is now beyond that, there is still no detail about when the mission may end.
Strictly speaking about the Air Force aircraft, people speculate that it is doing something to test an EmDrive in space from placing the spy satellite into orbit. Similar to the design of NASA’s space shuttles – the spacecraft’s mission objectives
remain closely guarded privacy. This theory was soon debunked by experts, who pointed out that a spacecraft’s orbital plane needs a lot of pressure to change which would consume its limited fuel supply very quickly. Basically, it would be ineffective to hit a target that had not already happened on the flight path. When the craft was introduced, conspiracy theorists suggested it could be a “space bomber,” even seven years before Trump created the Space Force.
Another theory from Spaceflight magazine is that it is a spy plane. “Space-to-space surveillance is a whole new ball game made possible by a fine group of sensors and sensor suites, which we think the X-373B was probably using to keep a close eye on China’s atheist space station.” Dr. David Baker, the editor of Spaceflight, told BBC News in 2012 that although this was also considered impossible based on the ship’s orbit. As fun as those explanations are, they are unlikely; the official explanation of the Air Force also does not give much.
“The initial goals of the X-3B are twofold; reusable spacecraft technology in space and operating tests for the future of America that returns to Earth, and can be tested. The X-37B Orbital Test Vehicle, or OTV, is an experimental test program
for the U.S. Air Force to demonstrate technologies for a reliable, reusable, unmanned space test platform, the Air Force said in a statement.”The technologies tested in the program include advanced direction, navigation, and control, thermal protection systems, avionics, high-temperature structures and seals, conformable reusable insulation, lightweight electromechanical flight systems, advanced propulsion systems, improved materials and automotive and landing.” For now, you either have to accept the official explanation, or just feel comfortable with the knowledge that a mysterious space drone is flying over our
heads, and only the US military knows it.