SolarBlack, a GSTP-funded activity, will be the first line of defense for Solar Orbiter. The inorganic layer is applied on top of a metal treated with Enbio’s CoBlast technique, which replaces the surface of the material with the heatshield skin. In the single-step process, the oxide layer on reactive metals such as titanium, aluminium or stainless steel is removed through grit-blasting and a new substrate – in Solar Orbiter’s case, SolarBlack or SolarWhite – is chemically bonded to the surface before a new oxide layer has a chance to form.
For SolarBlack, the skin applied is made of black calcium phosphate, which has a high emissivity and extremely high solar absorbance so it is able to efficiently absorb incoming solar radiation and re-emit it to the surrounding cold medium of space.