ISS Fly around views during STS-119. Credit: Nasa.

Thermal coatings using metamaterials have been developed for spacecraft and satellite surfaces by a group of researchers, including the UK’s University of Southampton.

Newly developed metamaterial optical solar reflector (meta-OSR) technology is designed to effectively radiate infrared heat away from it while reflecting most of the optical solar spectrum.

Optical solar reflectors (OSRs) play a vital role in the satellite or spacecraft’s thermal control operations.

They are attached to the exterior of the radiator panels, working to reject solar radiation and dissipate heat that is generated on-board.

OSRs are usually built from heavy and fragile quartz tiles that cannot be applied to curved surfaces and come with increased assembly and launch costs.

“Researchers demonstrated a new meta-OSR coating that uses metal oxide, which is patterned into a metamaterial with very strong infrared emissions.”

Other existing commercial coating solutions are based on polymer foils that quickly deteriorate in performance, making them unsuitable for missions lasting more than three to five years.

University of Southampton representative and the study principal investigator Otto Muskens said: “The meta-OSR technology is entirely based on durable and space-approved inorganic coatings, which can be applied onto flexible thin-film substances with the potential to be developed as a new technology solution.

“Since the assembly and launch costs of OSRs is several tens of thousands of US dollars per square metre, even small improvements in weight reduction can make a significant change to the space industry.”

Researchers demonstrated a new meta-OSR coating that uses metal oxide, which is patterned into a metamaterial with very strong infrared emissions that retain a low absorption of the solar spectrum.

They have also demonstrated a ‘smart’ radiator based on their metamaterial design that enables tuning of the spacecraft’s radiative cooling using another type of metal oxide.

The study was carried out by the META-REFLECTOR consortium, which also includes Italy’s Centro Ricerche Elettro-Ottiche, Danish nanoimprint developer NIL Technology, and Thales Alenia Space.

The consortium receives support from the two-year long Horizon 2020 space technology project from the European Union (EU).