President Trump signed a directive on Tuesday laying out the groundwork for his much-heralded Space Force to defend against enemies “up in space,” The Washington Post reports. In the signed policy directive, the president reportedly instructed the Defense Department to create the Space Force as a small part of the Air Force—much like how the Navy Department houses the Marine Corps, rather than as a whole new service as he initially wanted. “Our adversaries ... whether we get along with them or not, they’re up in space,” Trump told reporters on Tuesday. “And they’re doing it, and we’re doing it. And that’s going to be a very big part of where the defense of our nation — and you could say ‘offense,’ but let’s just be nice about it and let’s say the defense of our nation — is going to be.” The legislation to create the Space Force will still have to go through the congressional approval process. If approved, it will mark the first time the U.S. has created a new military branch since the Air Force was established in 1947. Air Force officials reportedly told the president that creating an entire new branch of the Defense Dept. would lead to “ unnecessary Pentagon bureaucracy,” but the administration could still push for a stand-alone Space Force Department sometime in the future.