Atomic oxygen erosion

Micrometre-scale scanning electron microscope image of atomic oxygen erosion of Kapton, typically used in multi-layer insulation of satellites. The central pillar of material is due to a metallic contaminant particle which serves to preserve the Kapton beneath it, while the polymer around it has been eaten away. Such results confirm ESA's new LEOX, Low Earth Orbit Facility atomic  oxygen generator is working well, because at microscopic scale the test materials look just like materials that have actually retrieved from orbit in the past.