High-power rocketry
High-power rocketry is a hobby similar to model rocketry. The major difference is that higher impulse range motors are used. The National Fire Protection Association (NFPA) definition of a high-power rocket is one that has a total weight of more than and contains a motor or motors containing more than of propellant and/or rated at more than 160 Newton-seconds (40.47 lbf·s) of total impulse, or that uses a motor with an average thrust of or more. Types High-power rockets are defined as rockets flown using commercially available motors ranging from H to O class. In the U.S., the NFPA1122 standard dictates guidelines for model rocketry, while NFPA1127 is specific to high-power rockets. In most U.S. states NFPA1122 has been adopted as part of the legal code. A smaller number of states use NFPA1127. Associations The Tripoli Rocketry Association and the National Association of Rocketry are the major sanctioning bodies for the hobby in the US, providing member certifications, and criteria for general safety guidelines. In most other countries, where HPR is supported, the regulations are similar to or derived from the Tripoli Rocket Association Unified Safety Code and the NAR High-power Certification system. In Australia, there are several prefectures of