Get all our news and commentary in your inbox at 6 a.m. ET. email Space Force’s First Battle Is With the US Army The newest force is relying on Army and Navy transfers to grow. But giving up missions is not in the military’s DNA. May 20, 2021 11:58 AM ET The fight for control of space is brewing — not the competition with China, but between the Space Force and the Army. Over the last several months, Space Force officials have been negotiating with their Army and Navy counterparts over what missions and personnel will transfer into the newest branch, which is part of the Department of the Air Force.