What does the acronym "HPR" stand for?

The term "HPR" stands for "High-Power Rocketry," which specifically refers to a segment of rocketry that involves rockets powered by high-thrust engines designed to produce significant amounts of thrust compared to those used in traditional model rocketry. High-Power Rocketry is characterized by its larger rocket sizes, more advanced construction techniques, and the potential for reaching higher altitudes as well as carrying heavier payloads.

HPR typically requires adherence to specific safety standards and guidelines established by organizations like the Tripoli Rocketry Association and the National Association of Rocketry. Such standards ensure safety during launches due to the increased risks associated with higher power levels of propulsion.

This answer captures the essence of what HPR represents in the rocketry community, focusing on the specialized nature of these rockets compared to lower power levels.