WASHINGTON — John Stopher, principal assistant to the secretary of the Air Force for space is stepping down from his post effective July 19. On Tuesday he submitted his resignation letter to President Trump.

In the letter to the president, Stopher said he plans to return to the private sector “where I can help align the world’s greatest innovators who are ready and able to solve the critical space challenges that lie ahead.”

Stopher praised the men and women of the Air Force and their accomplishments in the space arena. “Our Air Force is the strongest and greatest the world has ever known. We produce the world’s greatest space capabilities, an guided by our new strategy, we will give our Airmen the tools they need to safeguard the ultimate high ground.”

Stopher joined the administration in August 2017 as deputy undersecretary of the Air Force for space and director of the principal DoD space advisor staff. In April 2018 he became the principal assistant to the secretary of the Air Force for space.

In recent months, Stopher worked closely with former Air Force Secretary Heather Wilson to help prepare the Air Force to stand up a Space Force if Congress enacts a new service. Before her departure on May 31, Wilson created a Space Force Planning Task Force that has laid out a detailed blueprint to establish a space service. Stopher was in charge of the Air Force’s space portfolio, space procurement reforms and personnel initiatives the Air Force is proposing to increase the promotion rates of space officers. He was on a team of DoD and Air Force officials who briefed the Pentagon’s Space Force proposal to congressional committees.

Wilson last month awarded Stopher the Department of the Air Force’s “Decoration for Exceptional Civilian Service”

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...