As with low power model rockets, high power rockets are also constructed from lightweight materials. Unlike model rockets, high power rockets often require stronger materials such as fiberglass, composite materials, and aluminum to withstand the higher stresses during flights which often exceed Mach 1 (340 m/s) and over 3,000 m (10,000 ft.) altitude.
High power rockets are propelled by larger motors ranging from class H to class O. Their motors are almost always reloadable rather than single-use in order to reduce cost. Recovery and/or multi-stage ignition may be initiated by small on-board computers, which use an altimeter or accelerometer for detecting when to ignite engines or deploy parachutes.
High powered model rockets can carry large payloads, including cameras and instrumentation such as GPS units.