Flight testing of a university based H₂O₂/HDPE hybrid sounding rocket at KAIST

This paper reports results of manufacturing and flight testing of a laboratory scale sounding rocket using a 250 N class hybrid thruster. The propulsion system was configured with a storage tank, tubing lines, and a thruster. 90wt% H₂O₂ as an oxidizer and high density polyethylene as a fuel grain were used. With catalytic ignition and blow down feeding system, propulsion part could be simply made up. Ground test of propulsion system showed successful combustion using a MnO₂/Al2O₃ catalyst for catalytic ignition. The sounding rocket was composed of the propulsion system, recovery and flight data acquisition system, and carbon composite casing. Before the flight test, flight trajectory was simulated by developed code considering six degrees of freedom motion showing the reachable altitude of several hundreds of meters. Flight test result showed the propulsion system well functioned without any delay of ignition and the sounding rocket successfully launched. However, the maximum altitude was less than one hundred meter due to the flight direction change affected by a gust of the wind, which indicated the rocket was vulnerable to an aerodynamic disturbance with insufficient initial acceleration and over stably designed fins.