Rocket Motor Testing
State and federal law require all rocket engines to be independently tested before they may be sold in the United States.
The NAR Standards and Testing Committee performs this quality assurance for every individual rocket engine type and classification available to general consumers at its East Coast testing facilities in Massachusetts. The committee has a detailed Standards and Testing Motor Testing Manual which documents the exact procedures used for the certification process. A Standards and Testing Sport Rocketry Article. provides more information about the Committee and its equipment and operating procedures.
S&T not only tests new engine offerings, but re-tests each approved engine type from time to time in order to ensure repeatability and help identify creeping degradation in manufacturing or distribution practices. In addition, S&T collects data from https://www.motorcato.org/, where consumers have logged motor failures, to identify engines and engine lots that are in need of immediate testing.
Hobby rocket engines are tested according to criteria found in https://www.nfpa.org/ Codes 1125. These include accurate total impulse and time delay; sensitivity to shock, temperature, and other environmental considerations; adequacy of safety instructions; and gross operational correctness.
S&T's engine testing fixtures can process motors as fast as they can be prepared for firing, and measure variations in performance to hundreds of parts of a second.
For each motor type certified, S&T publishes a data sheet containing various static and operational parameters of the motor and including a typical thrust curve. Data sheets can be downloaded from the Certified Motors page.
NAR grants certification to two levels. The first, "NAR Certification," denotes that a given motor satisfies the requirements of NFPA 1122 for model rocketry or NFPA 1127 for high power rockety. The second, "Contest Certification," specifies that a certified model rocket motor is widely enough available to the general consumer to allow its fair use in NAR model rocket competition.
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