Additive manufacturing has emerged as an exciting new technology for design and manufacture of small spacecraft systems. Using 3-D printing, thermoplastic materials can be fabricated with any shape, and embedded cavities are easily achieved. Results of a where fuel materials are directly printed into the lower-2U of a prototype CubeSat are presented. Printed material is partially consumed as fuel during the spacecraft lifetime. Due to the relatively high specific impulse of the selected hybrid propellants, coupled with a portion of the spacecraft being consumed as propellant, there exists the potential to significantly increase available ΔV compared to hydrazine and the current generation of "green" spacecraft propellants. Prototype "thrust columns" with embedded fuel ports were printed from a combination of acrylonitrile butadiene styrene and a proprietary photopolymer blend. These thrust columns were manufactured with external triangular shapes to match the shape of a conventional CubeSat frame. Results from performance tests are presented. Hot-fire results include data from tests performed in ambient and vacuum conditions. Corona discharge at the ignition section was observed under specific vacuum conditions; associated results along hypothesized causes and solutions are discussed. Multiple test geometries and chamber pressures were evaluated to establish ignition reliability, and evaluate system performances.
展开▼