Definition of interplanetary dust particle hypervelocity impact protection levels provided by spacecraft multilayer insulation/thermal blankets is provided for the first time. Development of a new data-anchored shock-hydrocode-computations-derived ballistic limit equation in the hypervelocity impact range for representative two-wall Whipple shields, in which spacecraft multilayer insulation is the bumper material impacted by fused silica dust, is presented. A baseline configuration was adopted for analysis: 0.0176-cm-thick Kapton bumper (monolithic and layered), 2.54 cm standoff, and 0.0762-cm-thick titanium alloy Ti-6Al-4V rear wall. Significant efforts made to verify and validate the computational methodology with hypervelocity impact test data are also described. With a solid Kapton bumper, the critical particle diameter for causing incipient spall in the rear wall, which is chosen to be the failure criterion, is found to be in the range, with the largest and the smallest sizes corresponding to 30 and hypervelocity impact, respectively. When the bumper is layered in a manner similar to that found in actual blankets ( spacing), the critical particle diameter is indicated to be in the range.