Boeing X-37B after ground tests at Vandenberg AFB Wikimedia Commons

Boeing X-37B, a secretive spacecraft of the US Air Force (USAF) has completed 719 days in the earth's orbit, thus setting a new record for the most amount of time spent in earth's orbit by a spacecraft. Even though the spacecraft has been in the earth's orbit for nearly two years, the exact motive of the mission is still under the wraps.

It should be noted this is X-37B's fifth mission. The first mission named OTV-1 completed 224 days and nine hours in space, while the fourth mission OTV-4 completed 717 days and 20 hours. It is still unclear when the OTV-5 mission will be completed and the X-37B will leave the earth's orbit and land back on earth.

OTV-5 mission was launched on September 7, 2017, and interestingly, it was the first launch of an X-37B on SpaceX's Falcon 9 vehicle. It should be also noted that the X-37B is basically a miniature version of NASA's space shuttle.

Over the years, conspiracy theorists have suggested several speculations regarding the exact motive of this spacecraft. Soon after the launch of OTV-3, several conspiracy theorists alleged that the X-37B was sent to earth's orbit to spy on China's Tiangong-1 space laboratory. Some other conspiracy theorists believe that the Boeing X-37B has unknown extraterrestrial connections.

A few weeks back, Ralf Vandebergh, a Dutch astronomer had captured the image of the secretive X-37B. After capturing the image Vandebergh revealed that he has succeeded in capturing the photograph of the spacecraft after vigorously searching it for many months.

"When I tried to observe it again in mid-June, it didn't meet the predicted time and path. It turned out to have maneuvered to another orbit. Thanks to the amateur satellite observers' network, it was rapidly found in orbit again, and I was able to take some images on June 30 and July 2," said Vadebergh after capturing the photograph.