On 1 October 1975 the SAFEGUARD complex in North Dakota became operational. This complex, called the Mickelsen Complex after Army Air Defense Command [ARADCOM]'s third commanding general, Lt. Gen. Stanley R. Mickelsen, was located 100 miles northwest of Grand Forks. Its reason for being was to defend 150 Minuteman missiles located nearby and to provide a "light" defense of the upper-Midwest of the continent against ballistic missile attack.In a number of ways, the Mickelsen facility was a technological marvel. The 80-foot-tall truncated pyramid that housed the antennas for the MSR dominated the flat landscape around the town of Nekoma. The structure's four-foot-thick concrete walls were sloped at a 35-degree angle to provide hardening against the effects of nuclear blast. Each sloping surface of the pyramid held a radar antenna that was 13 feet in diameter and contained five thousand phased-array elements. The four faces of the MSR allowed it to search for targets coming from all directions, and it could acquire these targets at a range of 300 miles. The MSR worked in conjunction with a PAR near Cavalier, North Dakota, 25 miles northeast of the missile Site. This was also a phased-array radar, but it was designed to search in only one direction - toward the north. In the event of a Soviet attack, the PAR would detect incoming missiles at a range of I 800 miles, about the time the warheads were passing over the North Pole. Detection at this range would allow only six minutes to plan the battle against the approaching reentry vehicles. Computers associated with the PAR would determine the trajectory of incoming missiles and pass the information to the MSR for control of the defensive missiles that would attack the warheads. Two types of missiles were employed in the SAFEGUARD system. The high-altitude SPARTAN missile was built by McDonnell Douglas. It was a three-stage, solid-propellant rocket armed with a nuclear warhead that killed warheads by blast and X-rays that were lethal to warheads several miles away. SPARTAN was 55 feet long. The second missile, SPRINT, was a marvel of aeronautics and space technology. Built by Martin Marietta, it was designed to operate at hypersonic speeds in the earth's atmosphere; at its top speed, the missile's skin became hotter than the interior of its rocket motor and glowed incandescently. If one somehow could have trained an acetylene torch on the nose of the missile at this speed, the hot gases of the torch would have cooled the nose. The electronic components of the SPRINT were designed to withstand accelerations of 100 times gravity. The missile was 27 feet long, consisted of two stages, and used solid fuel. Like SPARTAN, SPRINT carried a nuclear warhead.
SAFEGUARD's "technical sweetness" was overshadowed by its limitations. With only one hundred missiles, the system could provide only limited protection to the ICBMs near Grand Forks and supply some measure of protection to the central United States against an accidental launch or a light ICBM attack. Moreover, SAFEGUARD was not the optimum system for the point defense of hard targets. It started out as the SENTINEL project, which was supposed to provide nationwide protection against a light ICBM attack. When President Nixon shifted the emphasis of the program to defending ICBM fields, the United States wound up using an area defense system for a point defense mission. The area defense concept involved the use of the large, powerful long-range radar systems that were hallmarks of the Mickelsen complex. In addition to being subject to blackout caused by the detonation of nuclear warheads, these radar systems could be attacked directly. Once they were destroyed, the SPARTAN and SPRINT missiles were electronically blind and therefore useless.
In the fall of 1975, the same limitations that hampered SAFEGUARD led to the inactivation of the Mickelsen SAFEGUARD complex. On Oct. 2, 1975, one day after SAFEGUARD became operational, the House voted to inactivate the system. DoD studies made available to the House Committee on Appropriations in September had shown that Soviet missiles with multiple warheads would be able to overwhelm the system. The vulnerability of SAFEGUARD's radar systems was also a factor in the committee's decision. DoD itself drove the final nail in SAFEGUARD's coffin. During proceedings of the House, it was discovered that DoD had been planning for two years to inactivate the North Dakota site on July 1, 1976. The House voted against SAFEGUARD, and the Senate voted several times on different proposals. Finally, in November 1975, the Senate passed a bill that would allow operation and testing of the site's perimeter acquisition radar but would close down the remainder of SAFEGUARD. In February 1976, the Army began carrying out the directions of Congress. Specifically, site technicians stopped the radiation of power from the missile site radar and began removing warheads and missiles from their launching cells. Furthermore, the Army started transferring personnel to other locations and began to dispose of excess property. The $5 billion complex, operational for only five months, was placed in caretaker status.