Hybrid rocket could be considered half-way from solid and liquid technologies since this chemical propulsion system stores the oxidizer and the fuel in two distinguished states. The most often employed configuration considers a liquid or a gaseous oxidizer which flows through a solid fuel channel and burns with the pyrolysis gases coming from the solid fuel regression. In this case, the fuel grain acts as a combustion chamber referring to solid propulsion whereas the oxidizer stored in a separated tank, and the injection system refer to liquid technology.

The repository contains data [1] on a hybrid rocket engine performance, and relations of the specific impulse on the mixture ratios for

• H₂O₂ -wt87.5%-HDPE
• H₂O₂ -wt98%-HDPE
• N₂O₄ -CH₆N₂

Source:

Jean-Yves Lestrade, Pierre Prévot, Jérôme Messineo, Jerôme Anthoine, Santiago Casu, et al. Development of a catalyst for highly concentrated hydrogen peroxide. Space Propulsion 2016, May 2016, Rome, Italy. hal-01353568