Combustion Characteristics of 5-Aminotetrazole-Based Propellant for Laser-Augmented Propulsion

Laser-augmented chemical propulsion can provide controllable thrust for space vehicles depending on the laser power, but propellant in this technology is required to produce green, pure gaseous products and with high optic sensitivity. 5-Aminotetrazole (5-ATZ) can provide pure and clean combustion exhausts, so that 5-ATZ is a potential compound for laser-augmented chemical propulsion. Two 5-ATZ-based propellants (95% 5-ATZ/5% carbon and 94% 5-ATZ/5% carbon/1% phenolic resin, in mass %) were studied in terms of thermal properties, optical properties, and combustion characteristics. Experimental results show pure 5-ATZ (baseline) and the selected 5-ATZ-based propellants are little different in thermal properties, but the optic reflectivity of 5-ATZ mixed with 5% carbon is lower than that of pure 5-ATZ. The 5-ATZ-based propellants reveal a unique porous bubble formation on the irradiated surface, and the bubble life depends on laser power and combustion pressure complexly. The experimental results obtained show that the phenolic resin is useful to improve regression rate under low-pressure operations (0.3 MPa), and the regression rates of 5-ATZ-based propellants depend on the laser power level and combustion pressure.