Conspiracy theorists suggest the X-37B plane is testing a new kind of weapon, or carrying out surveillance. The Air Force remains silent.
The US has landed its experimental plane in Florida, bringing to an end a two-year mission that is a complete secret.
The U.S. Air Force’s unmanned space plane has flown four clandestine missions to date, carrying secret payloads on long-duration flights in Earth orbit.
The robotic vehicle resembles NASA’s famous space shuttle but is much smaller. The X-37B is about 29 feet (8.8 meters) long and 9.5 feet (2.9 m) tall, with a wingspan just less than 15 feet (4.6 m). At launch, it weighs 11,000 lbs. (4,990 kilograms).
The X-37B’s payload bay (the area in which the cargo is packed) measures 7 feet long by 4 feet wide (2.1 by 1.2 m) — about the size of a pickup truck bed. Just what the X-37B carries in there is unclear, however. Air Force officials generally comment only on the overall goals of the program, stressing that each payload is classified.
As you can imagine, this started a explosive debate online with hundreds of theories about what they are really doing up there.