MLI Layer Spacers

Dacron Net / Polyester Spacer Material

Multi-layer insulation (MLI) layer spacers are porous Dacron netting or polyester scrim materials, approximately 0.1 millimeters thick, placed between reflective insulation foils to prevent direct contact that would conductively short-circuit the thermal radiation barriers. Functioning passively in high vacuum, these low-conductance separators maintain required physical spacing across blanket assemblies. The lunar environment complicates polymer spacer longevity due to continuous vacuum exposure and cumulative total ionizing dose radiation effects, which drive polymer aging over a 50-year operational lifetime where material degradation necessitates full blanket replacement.

Dacron net or polyester spacer material between MLI reflective layers preventing direct contact (which would short-circuit the radiation barriers).