Title: Fabrication of Thermal Protection Systems Via 5-Axis Additive Manufacturing

Authors: Alison I. Kennedy, Zachary McNulty, Steven R. Nutt

DOI: 10.33599/nasampe/s.24.0102

Abstract: Thermal protection systems (TPS) shield aerospace vehicles from extreme heat fluxes during atmospheric reentry. TPS fabrication relies on hand layup techniques that are time- and resource-intensive. Herein, we demonstrate a method to produce TPS via additive manufacturing. A specially formulated composite consisting of phenolic resin, carbon fibers, nanoclay, and phenolic microballoons showed char yield values more than 50 wt%, which were similar to legacy systems. Through the incorporation of nanoclay, the viscosity was controlled to be suitable for extrusion while maintaining the printed geometry as values did not reach 1×10^4 pa∙s until temperatures are greater than 100 °C. A five-axis syringe-based 3D printer was developed and used to print prototype TPS samples for testing. Tilt and rotation were implemented in the substrate to allow printing of contoured tiles commonly required for aerospace structures beyond typical additive manufacturing techniques. This technology enabled direct deposition of TPS onto the metallic backshells of vehicles, potentially reducing production costs and time.

References: [1]“The Atmospheric Reentry Demonstrator,” European Space Agency, 1998. [2]Glass, David “Ceramic Matrix Composite (CMC) Thermal Protection Systems (TPS) and Hot Structures for Hypersonic Vehicles,” in 15th AIAA Space Planes and Hypersonic Systems and Technologies Conference, 2008. Accessed: Jun. 06, 2023. [Online]. Available: https://ntrs.nasa.gov/citations/20080017096 [3]Weinzierl, M. , Sarang, M. “The Commercial Space Age Is Here.” Harvard Business Review Accessed: Jan. 10, 2024. [Online]. Available: https://hbr.org/2021/02/the-commercial-space-age-is-here [4]Witze, Alexandra “2022 was a record year for space launches,” Nature, vol. 613, no. 7944, p. 426, Jan. 2023, doi: 10.1038/D41586-023-00048-7. [5]Ellerby, D., Stackpoole, M., Gasch, M., Peterson, K., Milos, F., Venkatapathy, E., Prabhu, D., Skokova, K., Violette, S. “Sustaining Phenolic Impregnated Carbon Ablator (PICA) for Future NASA Missions Including Discovery and New Frontiers Background-PICA,” 2019. [6]Kam, J., and Amar, A. “Orion Aerosciences and Thermal Protection System Overview”. [7]Kim, H., Brunovska, Z., and Ishida, H. “Synthesis and thermal characterization of polybenzoxazines based on acetylene-functional monomers.” Polymer, 1999, vol. 40, pp. 6565-6573 [8] Torres-Herrador, F., Eschenbacher, A., Coheur, J., Blondeau, J., Magin, T. E., and Van Geem, K. M. “Decomposition of carbon/phenolic composites for aerospace heatshields: Detailed speciation of phenolic resin pyrolysis products,” Aerosp Sci Technol, vol. 119, p. 107079, 2021, doi: 10.1016/j.ast.2021.107079.. [9]Mishra, J., Rao, C., Bose, P., Nath, N., and Rao, G. “Experimental Studies of Resin Systems for Ablative Thermal Protection System,” Def Sci J, vol. 71, no. 2, pp. 289–295, 2021, doi: 10.14429/dsj.71.16252. [10]Hong, F., Hodges, S., Myant, C., and Boyle, D. “Open5x: Accessible 5-axis 3D printing and conformal slicing,” Conference on Human Factors in Computing Systems - Proceedings, Apr. 2022, doi: 10.1145/3491101.3519782.

Conference: SAMPE 2024

Publication Date: 2024/05/20

SKU: TP24-0000000102

Pages: 9

Price: $18.00