Rocket Motor Information
State and federal law require all rocket engines to be independently tested before they may be sold in the United States.
At its testing facilities at the Massachusetts Institute of Technology, the NAR Standards and Testing Committee performs this quality assurance for every individual rocket engine type and classification available to general consumers.
S&T not only tests new engine offerings, but re-tests each
approved engine type once in every three-year cycle to ensure
repeatability and help identify creeping degradation in manufacturing
or distribution practices. In addition, S&T collects and reduces
data from motor malfunction reports sent in by
consumers, using this data to trigger special testing of questionable
engines and engine lots.
Model rocket engines are tested according to criteria found in National Fire Protection Association (NFPA) Codes 1122 (for model rocket motors) and 1127 (for high-power rocket motors). 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 computer-controlled engine testing fixtures can process
motors as fast as they can be prepared for firing, and can measure
variations in performance to hundreds of parts of a second.
For each motor type certified, S&T publishes a data sheet, available from NAR Technical Services (NARTS), containing various static and operational parameters of the motor and including a typical thrust curve.
NAR grants certification to two levels. The first, "NAR Certification," denotes that a given motor satisfies the requirements of NFPA 1122 or NFPA 1127. The second, "Contest Certification," specifies that a NAR-certified model rocket motor is widely enough available to the general consumer to allow its fair use in sanctioned model rocket competition.