As a subset of model rocket projects, analyses on the propellant are discussed. Notable activities proposed and carried out by our students include the infrared spectroscopy experiment that identifies the composition of the propellant and the extraction experiment that determines the mixture ratio of those substances. These experiments are practical yet rarely employed in model rocket projects, perhaps because the required equipment is typically not found in engineering labs but in chemistry labs. In these activities students integrate knowledge and skills across academic disciplines, and uncover what manufacturers of hobby rockets prefer to keep as a propriety secret: the exact chemical make-up of their motors, made of black powder. Thermochemical analyses of the propellant are also discussed. Activities presented in this paper are appropriate for university-level engineering courses, and require no prerequisite courses beyond the freshmen-level chemistry.