Air Force X-37B Space Plane Launches On Fourth Secretive Mission

The military’s secretive X-37B space plane launched on Wednesday morning, riding atop an Atlas V Rocket into orbit from Florida, yet the Air Force is saying little about the unmanned spacecraft’s newest mission.

Wednesday’s launch marks the fourth orbital excursion for the reusable, robotic space plane, according to Space. The first launch window opened at 10:45 a.m. EDT (1445 GMT), and liftoff took place at 11:05 a.m. from Cape Canaveral Air Force Station in Florida. The three previous X-37B missions also launched from Canaveral, and all three landed on autopilot at California’s Vandenberg Air Force Base. For this mission, the space plane may land at Kennedy Space Center in Florida, though Vandenberg is still a possibility.

The three prior missions, which have taken place since April 2010 and have involved two of the X-37B planes, have logged a total of 1,367 days in space. The most recent mission, which landed in October 2014, as the Inquisitr previously reported, launched in December 2012, lasting a record 674 days in orbit.

Though the space planes’ missions have been shrouded in secrecy, some information is known about the X-37B. Two of the space planes have purportedly been built, and the selection of which one is launched is dependent upon the experimental objectives of each mission, according to Air Force spokesman Capt. Christopher Hoyler. Measuring 29-feet-long by nine and a half-feet-tall, the X-37B boasts a 15-foot-wingspan and a cargo hold roughly the same size as the bed of a pickup truck. Built by Boeing, the robotic space planes are designed to launch atop a rocket like the Atlas V, orbit, and then re-enter and land in much the same way that NASA’s space shuttle did.

For the first time, the military has revealed some of the payload going into orbit with the X-37B for this mission, as AOL reports. The space plane is carrying an advanced materials investigation aloft for NASA, and an experimental propulsion system, an ion engine called a Hall thruster, will also be tested. The LightSail spacecraft, a solar-sailing demonstrator built by the nonprofit Planetary Society, was also launched atop the Atlas V alongside the X-37B space plane on Wednesday as well.

[Image: ULA via Twitter]