The Military Auxiliary Radio System (MARS) is a United States Department of Defense sponsored program, established as a separately managed and operated program by the United States Army, and the United States Air Force. The United States Navy-Marine Corps program closed in 2015. The program is a civilian auxiliary consisting primarily of licensed amateur radio operators who are interested in assisting the military with communications on a regional and national level when access to traditional forms of communication may no longer be available. The MARS programs also include active duty, reserve, and National Guard units; and Navy, Marine Corps units.