With the rapid development of SmallSats/CubeSats and space computing, the current aluminum (Al) bulk shielding technology poses challenges in Size, Weight, and Power (SWaP) requirements. The bulk shielding thickness is determined by the electronics with the least radiation resistance, which prohibits wider adoption of Commercial-off-the-shelf (COTS) electronics and results in increased system weight. In addition, the absence of advanced thermal management technologies for SmallSats/CubeSats largely limits the adoption of high-power, low-price, and readily available COTS electronics. To address these challenges, we developed an innovative 3D-printed, lightweight polymer composite radiation shield comprising of a Metal Oxide Polymer Composite (MOPC) layer and a Fiber Reinforced Polymer Composite (FRPC) layer that is compatible with other polymer-based radiation shielding composites. Specifically, the MOPC utilizes high-atomic-number metal oxides that are infused into the base polymer to achieve superior radiation attenuation performance than Al. FRPC utilizes aligned carbon fibers in the same base polymer to achieve high in-plane thermal conductivity for electronics heat dissipation. In addition, such a shield is manufactured by the advanced five-axis Direct Ink Writing (DIW) 3D printer for further improved thermal transport and structural strength. Further, the 3D-printed shield enables locally enhanced spot shielding to provide additional radiation shielding for sensitive electronics without increasing the overall shield thickness. For MOPC, we have achieved an up to 7.4x increase in photon mass attenuation coefficient compared with Al and 18%–26% weight reduction for electron attenuation compared with Al at GEO. For FRPC, we achieved 2.55 W/m-K in-plane thermal conductivity, which is ~4x higher than the base polymer. Overall, the shield prototype can achieve 7° C reduction in CPU temperature or a 22.5% increase in CPU power, and if spot shielding is utilized, an estimated 62% weight reduction for 1U CubeSat systems can be achieved.
Xiao et al. (Sun,) studied this question.