What’s the deal with laughing gas and rubber?
All rocket motors have some form of “fuel” and an “oxidizer.” In solid rocket motors the oxidizer is embedded into the fuel (like an Estes rocket motor) and when lit will burn until depleted. In liquid rockets the oxidizer is usually liquid oxygen and the fuel another liquid like hydrogen or kerosene. In our hybrid motor we used Nitrous Oxide (N2O or laughing gas) as an oxidizer and hydroxy-terminated polybutadiene (HTPB or rubber) as the fuel. Both of these can be safely stored without special precautions and will not react when put together. Finally, N2O has the nice quality of self-pressurizing when at room temperature so that the space ship didn’t need complicated turbo pumps or plumbing to move the oxidizer into the combustion chamber.
