What oxidizer is most commonly used in commercial hybrid rocket motors?

The most commonly used oxidizer in commercial hybrid rocket motors is nitrous oxide (N2O). This choice is correct due to several key factors that make nitrous oxide particularly advantageous for hybrid propulsion.

First, nitrous oxide is a stable, easy-to-handle oxidizer that can be stored at room temperature, which simplifies the logistics of transport and engine integration. This operational convenience is beneficial for commercial applications where efficiency and safety are paramount.

Second, nitrous oxide can serve a dual purpose as both an oxidizer and a foaming agent, enhancing the performance of the propellant mixture. It decomposes upon heating to release oxygen, which facilitates the combustion of hydrocarbon fuels used in hybrid rocket motors, such as rubber or other polymer-based fuels.

Additionally, the performance characteristics of nitrous oxide, which include a favorable specific impulse and manageable combustion temperatures, align well with the requirements for hybrid rocket systems. This makes it suitable for a range of applications, from research and development to commercial launch services.

In contrast, while liquid oxygen and hydrogen peroxide are effective oxidizers, they require more stringent handling and storage conditions, which can complicate their use in commercial settings. Ammonium perchlorate, primarily used in solid rocket propellants, is