X-37B has spent 500 days in the earth's orbit for a secret mission. The plan was made by Boeing as an orbital space vehicle and rumored said the plane was built as a weapon carrier or spy satellite..
X-37B is the modified version of X-37A which was built for NASA by airplane maker Boeing since 1999. The U.S. Air Force version has conducted multiple missions since the project was announced in 2006. Its last secret mission began on May 2015, reports CBS News, as its fourth flight.
Previously, the X-37B had conducted three secret missions which logged a combined 1,367 days in orbit. Similar to the previous missions, the fourth mission, the Orbital Test Vehicle-4, abbreviated the OTV-4 also has very little details as reported by Space. There was no details about mission objectives or other detail information such as orbital parameters or mission duration.
The first X-37B orbital mission was launched on April 22, 2010 until Dec. 3, 2010, spending 224 days in orbit. The second OTV mission spent 468 days in the orbit from March 5, 2011 to June 16, 2012. Its third mission lasted 674 days.
X-37 project initiated in 1999 as a NASA project, and designated to test the reusable space technologies. NASA appointed Boeing to become the main contractor of the project. Prior to its appointment, Boeing has already tested the experimental unmanned space plane the X-40 through its subsidiary Boeing Phantom Works. It develop many high classified advanced military products and technologies.
In 2004, the project was transferred to Defense Advanced Research Projects Agency (DARPA), and the X-37 project become classified project. In 2006, U.S. Air Force decided to further develop the first NASA version to become the second generation X-37B. The new generation was aimed to be able to spend more time in the orbit.
Some rumors said that the X-37B longer time in earth orbit was aimed to become spy satellite or weapon carrier. Pentagon has denied the rumors, but the details of X-37B and its mission remain a secret.
Watch the official video from Boeing about the secret space plane X-37B after its second flight below: