New Nano-Barrier for Composite Material Could Strengthen Spacecraft Payloads

Researchers at the University of Surrey have developed a robust nano-barrier for carbon fiber reinforced polymers (CFRPs) that could be used to strengthen and stabilize high-precision instrument structures for space missions.

CFRPs are used in current space missions, but their applications are limited because they absorb moisture. This moisture is often released as gas during a mission, causing the material to expand, which affects the stability and integrity of the structure. To minimize this problem, engineers may perform procedures such as drying, recalibrations, and bake-out, but these may not resolve the issue. The Surrey team’s multilayered nano-barrier bonds with the CFRP and eliminates the need for multiple bake-out stages and controlled storage of the material.

The researchers showed that their thin nano-barrier, measuring only submicrometers in thickness, compared to the tens of micrometers of current space mission coatings, is less susceptible to stress and contamination at the surface, maintaining its integrity even after multiple thermal cycles. The surface barrier blends with the mechanical properties of the composite, becoming part of the CFRP itself. The resulting enhanced composite material features mechanical integrity and a strength that is superior to the underlying composite, while remaining impervious to moisture and outgassing.

“We are confident that the reinforced composite we have reported is a significant improvement over similar methods and materials already on the market,” professor Ravi Silva said. “These encouraging results suggest that our barrier could eliminate the considerable costs and dangers associated with using carbon-fiber reinforced polymers in space missions.”

The researchers demonstrated production capability for a model-size component for the Sentinel-5 mission. The nano-barrier could be used for future European Space Agency (ESA) and NASA programs such as Copernicus Extension, Earth Explorer, and Science Cosmic Visions.

Christian Wilhelmi, head of Mechanical Subsystems and Research and Technology Friedrichshafen at Airbus Defense and Space, said, “We have been using carbon-fiber composites on our spacecraft and instrument structures for many years, but the newly developed nano-barrier together with our ultra-high-modulus CFRP manufacturing capability will enable us to create the next generation of nonoutgassing CFRP materials with much more dimensional stability for optics and payload support. Reaching this milestone gives us the confidence to look at instrument-scale manufacturing to fully prove the technology.”

The research was published in Nature Materials (www.doi.org/10.1038/s41563-019-0565-3).