SMDC: History: An opportunity to learn

By Sharon Watkins Lang (Command Historian)August 15, 2017

SPRINT Launch M2-42A, 24Aug1972
(Photo Credit: U.S. Army) VIEW ORIGINAL

Every event is a learning opportunity; this is particularly true in test and evaluation. With a perfect test, assumptions are proven, the algorithms are effective, and every component performs as expected. The test failures, however, can help with growth. Why did this happen? How did it happened? Was it an anomaly or a system defect? What about the future? Should operating procedures be changed?

The Sprint missile program conducted 76 flight tests throughout the history of the program. Of these, there were 34 intercepts planned. Thirty-two Sprint launches achieved a successful intercept. The events in August 45 years ago, however, provided a learning opportunity when the Sprint program experienced the first missile failure in the Meck-2 or M2, test series.

The M2 test program, which began in August 1971 with launches from Meck Island, was divided into elements based on tactical software process revisions and increasing degrees of complexity. The M2 test goals sought to evaluate the system design by employing "tests which stressed the least confident aspects of a particular function or subsystem." The objective of Sprint launch M2-42 was to evaluate the ability of the Missile Site Radar and its associated data processor to launch a Sprint missile toward a medium-range, medium-altitude intercept against a taped target.

On Aug. 17, 1972, in the 31st flight of the Safeguard antiballistic missile system, the Sprint launch proceeded according to procedures until seconds after the launch. At that time the missile experienced a premature flight termination, which as the UPI reports explained meant that the missile exploded.

According to the official history, "a catastrophic missile failure occurred at approximately 175 milliseconds after first stage ignition." The optical data from sensor located around the Kwajalein Missile Range showed an "explosive rupture of the missile in the vicinity of the junction of first and second stages."

At this point the flight safety command destruction was automatically issued to ensure that the missile did not violate protective boundaries.

Until the time of the explosion, all systems and all data appeared normal. The subsequent investigation traced the issue to a series of environmental tests conducted upon some of the Sprint motors. Specifically the FLA-70 motors had been subjected to temperature cycling and drop testing in their tactical containers." M2-42 was the first flight test for these environmentally tested motors.

Based on this assessment, actions were taken to preclude another such failure. Procedures for qualifying motors shipped in Propulsion and Control Assembly containers were revised. A new "safe drop" margin would be determined by stress analysis. And all motors already subjected to 12-inch drops in the PACA container would receive detailed X-ray examination prior to any future use.

Given the confidence that the failure of test M2-42 was the result of environmental testing and not system design, the test was repeated one week later. On Aug. 24, the command conducted M2-42A a repeat of the previous mission. The Sprint achieved a successful intercept of the simulated target, as verified by radar, at the time and place determined by the pre-launch computations. M2-42A achieved all of the goals established for the original test.

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