[3][4][5][6] The Space Force has absorbed the Army's satellite communications mission and the Joint Tactical Ground Stations, while the Army maintains the 100th Missile Defense Brigade and a downsized 1st Space Brigade.

[7] The SMDC is made up of several components, Active Army and full-time Army National Guard, due to the 24-hour a day, 7-day a week, 365-day a year nature of SMDC's mission:[8] The Army's involvement with ballistic missile defense can be traced back to the Nike Zeus program in the late-1950s, being developed to counter the Soviet Union's ballistic missiles, however, it was never deployed.

[13] Unlike Sentinel, which was intended to protect large areas of the United States, Safeguard was focused on defending the Air Force's missile fields and against a more limited nuclear attack from China.

Only one Safeguard site, at what is now Cavalier Space Force Station, ever reached full operating capability before the program was canceled under congressional pressure in December 1975.

The single operational Perimeter Acquisition Radar was repurposed as part of the NORAD early warning system and transferred to the Air Force in 1977.

Following the Bush and Clinton administrations, the Strategic Defense Initiative was significantly scaled back to focus on protection against limited strikes and the Army began to refocus on theater missile defense.

[17] It also began fielding the Joint Tactical Ground Station and Army Space Support Teams.

[19] The United States Army Futures Command, formed 24 August 2018, gives priority to modernization of air and missile defense.

[20]: minute 6:07 [21][22][23] Cross-functional teams[24][25] were instituted to oversee the modernization effort[26][27] in the areas of hypersonic systems,[28][29][30] maneuver SHORAD (M-SHORAD)[31] and Integrated Air and Missile Defense Battle Command System (IBCS).

Task Force Eagle was renamed the Army Satellite Operations Brigade in 2019.

[47][48] Responsibility for conducting these operations rest with Army Multi-Domain Task Forces and a new space formation called the Theater Strike Effects Group.