The ground segment consists of a fixed site located in the Satellite Operations Building at Schriever Air Force Base and a site at Vandenberg Air Force Base, California. The squadron also operated three geographically distributed Advanced Ground Mobile vehicles. At higher readiness levels and during exercises, squadron personnel deploy with United States Northern Command and United States Strategic Command to provide survivable, secure communications and command and control. Milstar has about 1500 terminals. As the Advanced Extremely High Frequency network becomes fully operational it will add 5000 additional terminals and serve forces from Canada, the United Kingdom and the Netherlands.