Evaluating novel materials in extraterrestrial environments
Due to their attractive properties such as high electrical and thermal conductivity, mechanical integrity, light weight, etc. carbon nanotubes have been envisioned as material, which has the necessary attributes to revolutionize aerospace engineering. Their light weight, but high performance has been particularly interesting because substituting regular materials such as copper or aluminium on board with carbon nanostructures would mean massive savings. It costs thousands of dollars to take just 1 kilogram of cargo into orbit!
To test whether carbon nanotubes are suitable for such purpose, they have been sent to low Earth orbit for more than 2 year cruise. That region contains UV radiation, ionized particles and atomic oxygen, all of which are known to degrade organic materials. It has been found that the outer layer of carbon nanotubes has been transformed into amorphous carbon. The effect was more evident when the samples were attached to the front of the station rather than the back. Despite increase in electrical resistance and deterioration of mechanical properties carbon nanotubes were still functional. It appears that maybe a layer protecting carbon nanotubes would be necessary to fully preserve their properties. Further studies are underway to put this technology in use.
Read more: http://www.sciencedirect.com/science/article/pii/S0008622316303943