To automate the fabrication of ablative Thermal Protection Systems (TPS), a novel in-situ curing additive manufacturing (AM) technology and high-performance composite materials will be developed. The state-of-the-art in-situ curing nozzle utilizes localized volumetric heating of the extrudate to rapidly cure the polymer and adhere it to the flight structure. Rollers following the thermoset printhead will consolidate the materials reducing voids and eliminating previously necessary repairs on fabricated TPS before launch. The composition of the composite materials will be easily varied to gradient the material properties through the thickness of the TPS. Highly insulative materials closer to the flight structure and highly structural materials closer to the stagnation point of the vehicle will be critical for high-performance TPS. Future implementation of a continuous fiber 3D printhead will allow printing of the honeycomb or iso-grid reinforcement to stop potential crack propagation in high shear environments. Additionally, a highly robust outer layer of continuous carbon fiber will be 3D printed on the TPS for enhanced mechanical reinforcement. The unique combination of the novel in-situ curing nozzle, high-performance thermoset composite materials, and a multi-axis robotic arm will enable automated and time-efficient fabrication of TPS with minimal defects. This technology will facilitate future NASA missions to the Moon and Mars by initializing an assembly line for atmospheric entry vehicles of the future.
The primary NASA application of the proposed technology will include full automation of the ablative TPS manufacturing process. The current fabrication methods used for ablative TPS are outdated requiring extensive time, manual labor, and costly repairs before launch. The innovation will enable automated rapid fabrication of TPS to facilitate the organization of an assembly line for atmospheric entry vehicles for NASA's future missions to the Moon and Mars.
In-situ curing technologies for extrusion-based additive manufacturing (AM) are widely applicable to 3D print many thermoset materials. These thermoset materials have advantageous key materials properties over traditional polymer-based AM, enabling significant manufacturing freedom of highly versatile polymers in many fields including biomedical, aerospace, defense, automotive, and many more.