Materials/Coatings and surfaces
Coatings and surfaces
coatingsWhat this is
Paints, anodized layers and optical coatings that control heat, light and wear on a surface.
A coating decides how much sunlight a surface absorbs and how fast it radiates heat away, and it can protect what is underneath.
Types
Pick a type to see its materials.
| Type | Materials | Ranking |
|---|---|---|
| White paints | none yet | — |
| Black paints | none yet | — |
| Optical solar reflectors | none yet | — |
| Anodize | 1 | — |
| Conductive coatings | none yet | — |
| Atomic-oxygen protective | none yet | — |
| Optical coatings | none yet | — |
What matters
The measurements we use to compare coatings and surfaces. Each one has a standard test and a direction: is higher or lower better?
| Measurement | Better when | How it is tested |
|---|---|---|
| Atomic oxygen erosionHow fast low-orbit oxygen eats the surface | lower | Flight (MISSE); ground ASTM E2089 |
| Outgassing, total mass loss (TML)Mass lost in vacuum that can fog optics | lower | ASTM E595 |
| Outgassing, condensable (CVCM)Vapor that recondenses on cold surfaces | lower | ASTM E595 |
| Solar absorptance (α)How much sunlight it absorbs | depends on the use | ASTM E903 |
| Thermal emittance (ε)How well it radiates heat away | depends on the use | ASTM E408 |
| Thermal cycling survivalHot-cold cycles survived without cracking | higher | ECSS-Q-ST-70-04 |
| Darkening under UV and particles (Δα)How much its sunlight absorption rises over the mission | lower | ECSS-Q-ST-70-06 |
| Dust abrasion wearSurface lost to regolith grit | lower | Abrasion tests with simulants |