As the summer of 1970 came to a close, the Safeguard Systems Command prepared for a milestone test.

On Friday, Aug. 28, a Spartan interceptor was pitted against its first live target, a Minuteman I intercontinental ballistic missile. It was also scheduled to be the first operational system test incorporating the prototype Missile Site Radar, MSR, and data center.

A miss at this point would require a reassessment and potential redesign of the radar. As one newspaper reported, it was a moment of truth for the radar and the system.

To date, the Spartan had undergone 15 launch tests achieving 11 successfull, two partially successful and two failed missions using static points or simulated targets.

Nevertheless, congressional opponents had renewed efforts to bar funding arguing that the system would not work. The "complicated radar system" would be "ineffectual against a surprise missile attack."

Mission M1-4 began with the launch of the Minuteman I from Vandenberg Air Force Base, Calif. Soon thereafter, the MSR, located on Meck Island in the Kwajalein Atoll, successfully acquired and tracked the target. The Spartan was launched from Meck, and guided by the MSR to achieve a successful exo-atmospheric intercept of the ICBM nose cone.

Neither the Spartan nor the Minuteman were armed during this test. Ground-based monitors determined that the test was a success. The Spartan interceptor had passed within a lethal distance of the target. In other words, in the event of an actual attack, a nuclear armed Spartan would have successfully destroyed the target. The interceptor and the radar had operated as planned.

The Pentagon announced the test on Monday morning ?-- "a crucial first time success for the disputed defensive weapon." Acknowledging that the engineers on Kwajalein knew the target was coming and that it had not employed penetration aids or decoys.

"What was demonstrated in the test was a coordination of the main radar and tracking system (MSR) and the first line of missile defense, the Spartan," a Pentagon spokesman noted. "This was the first test to see if the system works. It wasn't the ultimate test, but it was a milestone. The ultimate test is five years down the road when first site opens."

In a subsequent report, the Safeguard System Evaluation Agency validated the mission as the "first demonstration of an autonomous missile direction center exoatmospheric intercept. The Meck MSR, Missile Site Data Processor and Spartan subsystem were successfully integrated."