WASHINGTON, D.C. — NASA Administrator Jared Isaacman emailed employees on Friday morning outlining a reorganization that consolidates the agency's six Mission Directorates into four. The changes are intended to improve operational efficiency and focus resources on returning humans to the Moon and establishing a base there.

"I believe it is imperative to concentrate resources towards the highest priority objectives in the National Space Policy and liberate the best and brightest from needless bureaucracy and obstacles that impede progress," Isaacman wrote in his 3,000-word letter. He stated that no employees will lose their jobs and no field centers will be closed as part of the changes.

Isaacman identified five core missions in the letter: executing the Artemis Program to return humans to the Moon; building an enduring Moon Base; developing a Space Reactor Office for nuclear power in space; igniting a low-Earth orbit economy; and building more X-planes and launching science missions. Previously, NASA had six Mission Directorates overseeing its core areas including human exploration, science, and aeronautics.

NASA is combining Space Operations and Exploration Systems Development into a single Human Spaceflight Mission Directorate. Lori Glaze will serve as its Associate Administrator, with Joel Montalbano and Kelvin Manning as Deputies. The directorate's primary divisions are Low Earth Orbit, led by Program Manager Dana Weigel; Moon Base, led by Carlos Garcia-Galan; and Artemis, led by Jeremy Parsons, with the Artemis division renamed from Moon to Mars.

The Aeronautics Research and Space Technology Mission Directorates will be merged into a single Research and Technology Mission Directorate. James Kenyon will serve as Associate Administrator, with Wanda Peters as Deputy. Its primary divisions are Aeronautics, directed by Laurie Grindle; Advanced Research and Technology, directed by Greg Stover; the Space Reactor Office, with Steve Sinacore as Acting Director; and Space Communications and Navigation, directed by Kevin Coggins.

The Science Mission Directorate under Nicky Fox and the Mission Support Directorate under John Bailey will be unchanged. NASA will streamline overlapping functions within the Mission Support Directorate by shifting those responsibilities from headquarters back to field centers. The leaders of the Mission Directorates will report directly to Isaacman instead of Associate Administrator Amit Kshatriya, who will become NASA's chief engineer.

Under the changes, each field center will receive a basic level of operating funding to focus on its specialties rather than compete for funding across various Mission Directorate priorities. "We will adjust the funding distribution so Centers have the financial support needed to sustain the baseline critical capabilities independent of near-term mission assignment," he wrote. "In parallel, Centers will reduce the overhead burden applied to missions wherever applicable. This shift will allow Center Directors to focus on maintaining the infrastructure, workforce, and capabilities required for current and future missions."

Isaacman arrived at NASA Headquarters as Administrator five months before the letter and has kept most of the field center leadership in place. Field centers include the Johnson Space Center in Houston and the Kennedy Space Center in Florida.