New Thermal Coatings for Spacecraft, Satellites Use Metamaterials

A team of British researchers have developed new technology that could prompt a significant change in spacecrafts and satellites.

Metamaterial optical solar reflectors (meta-OSRs) are the first surface coatings on the outside of a spacecraft, designed to effectively radiate infrared heat away from it while reflecting most of the optical solar spectrum.

OSRs play a crucial role in the system’s thermal control. Glued to the external skin of the radiator panels, they reject solar radiation and dissipate the heat that is generated on board. They are commonly made of quartz tiles that combine thermo-optical properties with an ability to withstand the environment in space. However, quartz tiles are heavy and fragile, add significantly to assembly and launch costs, and cannot be applied to curved surfaces. Other commercial solutions based on polymer foils suffer from fast performance degradation and are therefore unfit for missions lasting more than three to five years.

The British research team demonstrated that a new meta-OSR coating is enabled by the use of metal oxide, a material commonly used for transparent electrical contacts, which, in this instance, is patterned into a metamaterial with very strong infrared emissivity while retaining a low absorption of the solar spectrum. The team also developed a “smart” radiator based on the metamaterial design that allows tuning of the radiative cooling of the spacecraft using another type of metal oxide.

“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,” says Otto Muskens, a professor with the University of Southampton and principal investigator of the study. 

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

Read more about the study HERE.