SpaceX to launch secret U.S. military spacecraft

A SpaceX Falcon 9 rocket will blast into space on Thursday night, carrying the U.S. military's secretive X-37B drone on its eighth mission.

The rocket is due to launch at 11:50 p.m., according to SpaceX, which said a backup window is available at the same time the following day.

The U.S. Space Force has said the drone's mission will include "a wide range of test and experimentation objectives."

"These operational demonstrations and experiments comprise next-generation technologies, including laser communications and the highest performing quantum inertial sensor ever tested in space," the service said in a statement last month.

"Mission 8 will contribute to improving the resilience, efficiency and security of U.S. space-based communications architectures," it added.

About the size of a small bus, the X-37B U.S. space drone looks like a mini version of the manned space shuttles retired in 2011. On previous missions, the X-37B has carried out tests for the U.S. space agency NASA.

In operation since 2010, the X-37B Orbital Test Vehicle was designed and built by Boeing for the U.S. Air Force, with launch services provided by United Launch Alliance.

It is 9 meters long, has a 4.6-meter wingspan, and is powered by solar panels.