Preliminary Framework for Uncertainty Quantification and Propagation of the Fission Surface Power System Mass Estimates

Estimating the mass of the Fission Surface Power (FSP) system is crucial to the success of integrating FSP into a Moon or Mars human mission architecture. Past and current estimates of the FSP system have been made using the EZ FSP Sizer tool, which is a nuclear power system sizing tool developed at NASA Glenn Research Center. The tool currently applies a 20% mass growth allowance to mass estimates. The purpose of this report is to introduce a preliminary framework that quantifies and propagates the uncertainty of FSP mass estimates produced using the EZ FSP Sizer tool, providing a method to produce probabilistic mass estimates of an FSP system. This work can augment the capabilities of the EZ FSP Sizer tool and lay a foundation to aid with future decision making. Sensitivity analyses were performed on parameters that were used to model probability distributions of FSP subsystem masses. Results point to the need of reducing mass estimate uncertainty through hardware development and empirical validation. Although the modeled uncertainties are first order, they can be useful for informing when and how mass estimates can be used reliably.