Advanced Ignition System for Hybrid Rockets for Mars Sample Return, Phase II

To return a sample from the surface of Mars or any of the larger moons in the solar system will require a propulsion system with a comparatively large delta-V capability. Consequently, significant propellant mass will be required. While it is technically feasible to generate O2 and CO propellants by electrolysis of CO2 from the Martian atmosphere, it will only work on bodies where there is significant CO2 in the atmosphere, and the mass of the required infrastructure (electrolyzer, batteries, solar panels) is substantial. A recent study showed that a hybrid rocket with multi-start capability trades more favorably than either a CO2 electrolysis system or a bipropellant system where the propellants are generated on Earth. Using a high-performance hybrid propellant combination and being able to restart the hybrid rocket are the keys. In previous and ongoing work, Ultramet has demonstrated that electrically heated open-cell silicon carbide foam can be used as an igniter for both monopropellant and bipropellant rocket engines. Due to its low mass, excellent oxidation resistance, and favorable electrical characteristics, the foam can be heated to 1300°C in just seconds, which enables it to quickly ignite any propellant flowing through it. The Phase I project demonstrated that a foam heater could be turned on and off any number of times and that it was capable of heating oxygen and igniting paraffin. Applied to a portion of the oxidizer stream in a hybrid rocket engine, this will provide multi-start capability. In Phase II, Ultramet will team with Parabilis Space Technologies to design, fabricate, and test a hybrid rocket ignition system suitable for use with O2, NTO, or MON-25 on a Mars ascent vehicle.