Low Cost Refractory Matrix Composite Thruster for Mars Ascent Vehicles

The long-term goal for this effort is to develop a low-cost, high-temperature thruster. Within the attitude control propulsion community, many efforts have focused on development of ultra-high temperature precious metal alloys and systems that give long life and good performance (e.g., Ir/Re). Those designs are driven by the desire to operate the thrusters at very high temperatures, which increases Isp performance through a reduction in the amount of film cooling needed. The results have been thruster technologies plagued by high costs and low manufacturability. This approach of "performance at all cost" is no longer tenable, particularly for robotic exploration/science missions like Mars Sample Return. Therefore, we seek a different approach. We believe we can achieve state of the art (perhaps better) levels of performance, with significant reductions in cost. The focus of our innovation is on the development of a refractory matrix composite material that uses cheap, commercially available materials and then use fast, affordable manufacturing techniques to make a low cost, high performance thruster. Our starting materials are two order of magnitude cheaper than Ir/Re systems! Our proposed manufacturing process is likewise low cost, further contributing to the overall low cost thruster. The basic Phase I project includes small scale fabrication experiments to identify the manufacturing parameters needed to achieve a fully-dense composite. Then, we will fabricate sample coupons of various composition and measure hardness (as a relative indicator of tensile strength), to determine the range of composite parameters that will give the highest specific strength. More »