Monte Carlo Analysis for Spacecraft Thermal Protection System Design

This paper demonstrates a Monte Carlo analysis technique to establish margins on sizing a thermal protection system and identifies the chief sources of uncertainty in the material response modeling. Monte Carlo sensitivity and uncertainty studies are performed for the thermal protection systems of the Stardust Sample Return Capsule, Mars Exploration Rovers, and X-37 wing leading edge, using the Fully Implicit Ablation and Thermal response code. The computation results are presented and discussed in detail. It shows that a Monte Carlo approach provides more insight than the traditional Root-Sum-Square method into the relationship between the thickness margin of a thermal protection system and the probability of maintaining the temperature of the underlying material within specified requirements. Nomenclature erfi = inverse error function N = total number of samples R = random number x = input parameters y = output of interests σ = standard deviation * σ = mean x