WASHINGTON — After less than four months since the official launch of the Space Development Agency, the office’s first leader has stepped down.

Pentagon spokeswoman Heather Babb said Fred Kennedy will return to a role at the Defense Advanced Research Projects Agency, adding that an acting director for the SDA will be announced “soon.”

"There is no change to the mission or activities of the Space Development Agency,” Babb said in a statement. “SDA will drive the department’s future threat-driven space architecture and will accelerate the development and fielding of the new military space capabilities necessary to ensure our technological and military advantage in space for national defense.”

Space News first reported Kennedy’s exit.

The SDA is part of a broader reorganization for the Defense Department’s space efforts. Stood up by Undersecretary of Defense for Research and Engineering Mike Griffin, the office had been tasked with developing a layer of small, inexpensive low-Earth orbit satellites that will transfer data between space and ground assets.

The resignation comes at a time when the SDA had outlasted its chief opponent inside the Pentagon. Air Force Secretary Heather Wilson, who departed in May after two years as the service’s top civilian, fiercely opposed the SDA, openly questioning the need for its existence; her exit has left Matt Donovan in the acting position, who this week told Defense News he supports the SDA.

This week John Stopher — Wilson’s space adviser and another SDA opponent — resigned from his post.

Multiple sources told Defense News last week that Stopher would be removed from his post at the behest of Air Force leaders who wanted to break from Wilson’s space policies. The sources pointed to Stopher’s role in framing Wilson’s public comments on the space enterprise reorganization, and they said he was a dominant force in slow rolling Space Force-related policies.

Friday also marks the last day in the building for acting Secretary of Defense Patrick Shanahan, who had been the most vocal proponent of the SDA, apart of Griffin.

Valerie Insinna in Washington contributed to this report.