scope:

Purpose

The purpose of this Standard is to provide a consistent methodology for developing pyroshock test criteria for NASA spacecraft, payload, and launch vehicle hardware during the development, qualification (Qual), flight acceptance (FA), and/or protoflight (PF) test phases of the verification process. Various aspects of pyroshock testing are discussed herein, including test environments, methods and facilities, test margins and number of exposures, control tolerances (when applicable), data acquisition and analysis, test tailoring, dynamic analysis, and prediction techniques for pyroshock environments.

The most accurate simulation of the flight pyrotechnic environment is obtained for potentially susceptible hardware by testing with flight pyrotechnic devices on actual or closely simulated flight structure. However, high-fidelity flight structure is not usually available early in a program, and this approach does not provide magnitude qualification margin over flight. The alternative approach described in this Standard is to perform qualification or protoflight pyroshock simulation tests on potentially susceptible flight or flight-like hardware assemblies as early as possible, then to activate actual pyrotechnic devices on the flight system to improve pyroshock environment predictions and as a final verification. The advantages of this approach are that it may reveal potential hardware deficiencies early in the development program, and it allows the application of a qualification/protoflight margin to assembly-level pyroshock tests. The disadvantages include the potential for incorrect estimates of the pyroshock environment due to limitations of measurement methods and analysis techniques available today and the difficulty in accurately simulating a specified pyroshock environment at the assembly level. Regardless, testing on actual or closely similar flight structures is essential for final system verification.

Applicability

This Standard is applicable to the development of pyroshock test criteria for NASA spacecraft, payload, and launch vehicle hardware during the development, qualification, flight acceptance, and/or protoflight test phases of the verification process. Verification programs that meet or exceed the endorsed requirements for pyroshock testing set forth in this document shall be considered compliant with this Standard.

Shock testing requirements for hardware utilized in Range Safety Systems, and the methodology for tailoring those requirements for a specific program, are contained in Air Force Space Command Manual 91-710 (AFSPCMAN91-710). The Range has specific requirements for margins, minimum test levels, number of shock applications during testing, test tolerances, and testing unique to shock isolators.

This Standard is approved for use by NASA Headquarters and NASA Centers, including