Having previously flown on Atlas V launch vehicles, the next mission (mission 5) of the X-37B/OTV unmanned mini-space shuttle for the US Air Force will be launched on a SpaceX Falcon 9. The US Air Force confirmed this assignment which is thought to have been actually booked a year or so beforehand. The launch will take place in August 2017. The flight follows the landing of the previous X-37B/OTV mission 4 on 7 May.
The US Air Force has two X-37B craft in its fleet but declines to identify which is used on each flight. The craft are variously used for reconnaissance of Earth and of other spacecraft, as well as testing of new technology.