The present work performs analyses to estimate the thickness and mass of the C–C composite armor to protect foldable, lightweight radiator panels for fission surface power systems against micrometeoroids’ impact for >10 years on the lunar surface. The panel is comprised of 10 modules of Cs-Ti heat pipes and highly oriented pyrolytic graphite (HOPG)/Ti heat-spreading fins. The analyses are for vertically erected panels impinged by micrometeor particles with densities of 1.0 g/cm3 and 2.5 g/cm3. The obtained estimates for the perforation and penetration probabilities of the Cs-Ti heat pipes and the HOPG/Ti heat-spreading fins, respectively, are functions of the applied thicknesses of the C–C composite armor.

These estimates are based on three cumulative flux micrometeor environmental models by the U.S. National Aeronautics and Space Administration (NASA) and the European Space Agency. For a 5% perforation probability, the thickness of the C–C armor of the heat pipes varies from 0.8 to 1.03 mm, compared to only 0.20 to 0.22 mm for a 5% penetration probability of the HOPG/Ti heat-spreading fins.

Doubling the perforation and penetration probabilities to 10% decreases the thicknesses of the C–C composite armor by 25% to 28% for the heat pipes and to 0.026 to 0.036 mm for the heat-spreading fins. For 10% perforation and penetration probabilities, the areal density of the armored radiator panel of 10 modules is 2.98 kg/m2. This is within NASA’s desired target in the present work of ≤3.0 kg/m2 and the ~1/3 to 1/2 state of the art for lunar fission surface power systems.