Research at Stanford University beginning in 1997 led to a class of very high regression rate fuels for use in hybrid rockets. This class of liquefying fuels produces a very thin, low viscosity, low surface tension liquid layer on the fuel surface when it burns. The liquid layer hybrid combustion theory was developed based on this observation as a practical tool for predicting regression rate of liquefying fuels. In addition to liquefying fuels, SPG also has extensive experience with traditional polymeric fuels.
SPG personnel are also experienced in the handling and operation of numerous oxidizers. The list of oxidizers includes liquid oxygen, nitrous oxide, mixtures of nitrous oxide and oxygen (Nytrox), high-test peroxide, and mixed oxides of nitrogen (dinitrogen tetroxide and nitric oxide mixtures).