https://techcrunch.com/2017/09/07/spacex-successfully-launches-mysterious-x-37b-spaceplane-and-recovers-first-stage/

SpaceX can add another first to its ever-increasing list: On Thursday, it successfully launched an the U.S. Air Force’s X-37B experimental spaceplane for the first time. This makes it the only launch provider to accomplish this besides the United Launch Alliance, and should help ensure SpaceX gets more business from U.S, defense contracts in future.

The launch vehicle used was SpaceX’s Falcon 9 rocket, which took off from the company’s LC-39A launch facility at Kennedy Space Center on Thursday morning at 10 AM ET (7 AM PT). The Falcon 9 deployed the X-37B Orbital Test Vehicle, as the payload is officially called, and then its first stage booster returned to Earth for a planned recovery at Cape Canaveral Air Force base via SpaceX’s LZ-1 landing pad. The goal was to get the launch up before the arrival of Hurricane Irma, and they succeeded.