United States Air Force is preparing to launch its top-secret Boeing X-37B Orbital Test Vehicle aboard a SpaceX Falcon 9 rocket later this year.
Air Force Secretary Heather Wilson, displaying a model of the unmanned spaceplane, disclosed the service’s launch plans for the fifth X-37B mission during a Senate Armed Services Committee hearing Tuesday.
Wilson didn’t disclose why the Air Force selected Elon Musk’s SpaceX over United Launch Alliance (ULA), who launched the first four X-37B missions aboard its Atlas 5 rockets.
The X-37 vehicle returned from its fourth mission May 7, landing at the Kennedy Space Center after 718 days in orbit.
There are actually two Boeing-built X-37 spacecraft. The Air Force has not indicated which X-37 craft will be launching aboard the SpaceX rocket. However, the fact that the service has been alternating missions between the two craft, and that the second X-37 was the one that landed in May, means that it’s likely the first X-37 is due up for the next mission.
The Air Force said it intends to continue building “upon its fourth mission collaboration with experiment partners. The mission will carry the Air Force Research Laboratory (AFRL) Advanced Structurally Embedded Thermal Spreader (ASETS-11) to test experimental electronics and oscillating heat pipes in the long duration space environment.”
The X-37 is a secret Air Force program, with the first space plane launching on April 22, 2010 and spending roughly 224 days in orbit. The Air Force said that all together, the four missions have spent a total of 2,085 days in space. Built by Boeing’s Phantom Works division, each spaceship has a wingspan of nearly 15 feet (4.5 meters) and a length of more than 29 feet (8.9 meters).