In 1970, the Safeguard program moved into a new phase of testing. Both the Spartan and the Sprint missiles would be launched from a new prototype complex specially constructed on Meck Island, at the Kwajalein Missile Range.

As Safeguard engineers explained, the M-1 series of tests was designed "to prove in the basic concept of the system elements working together."

In previous tests components were tested individually or in limited coordination. The new facility would provide a controlled live target environment. The resulting data was "intended to provide answers to critical design problems" verifying concepts and evaluating system functions.

They would also serve "to validate the software simulations." The simulations were of particular concern as they were deemed "essential to the success" of the Safeguard program.

The Missile Site Radar, or MSR, objectives for the Meck System Test Program for example were fourfold. These were:

• Provide a near-tactical environment for gathering system performance data to aid in development and evaluation of the SAFEGUARD deployment
• Gather S-band radar data for reentry physics research
• Gather data to evaluate concepts for future defense systems
• Gather data for evaluation of tactical and experimental target systems.

Having completed 42 tests at White Sands Missile Range, New Mexico, the first Sprint launch from the Kwajalein Missile Range was scheduled for Oct. 28, 1970. As a terminal, or low altitude interceptor, the Sprint was designed for speed - with projected acceleration loads of 100g's.

In this test (M1-9), the live Sprint missile was launched from Meck Island. The 27-foot-long, short range interceptor was to be guided by the MSR to intercept a fixed endo-atmospheric space-point in a demonstration of the initial system software capability. Although the launch went as planned, flight safety destruct was initiated soon after takeoff because a premature launch signal indication created an erroneous signal to the MSR.

As a result, the radar beams were incorrectly positioned. The test ended at 0.872 seconds.
Following an analysis of the event, the Safeguard team decided to repeat the experiment. Test M1-9A, conducted in December 1970, duplicated the objectives of the initial Sprint test.

All systems performed as expected and the Sprint successfully intercepted the space-point about 10 seconds after launch. This therefore became the first MSR/missile site data processing guided Sprint intercept of a fixed endoatmospheric spacepoint. Everything performed as planned and the test met all M1-9A mission objectives.

M1-9 was the first of 34 Sprint System tests conducted at the Kwajalein Missile Range. All 34 included intercept attempts of live or simulated targets. Of these, 32 were declared successful intercepts.