Modeling science objectives within a probabilistic risk assessment

The Radiation Belt Storm Probes (RBSP) mission is being designed to help us understand the Sun´s influence on Earth and near-Earth space by studying the Earth´s radiation belts on various scales of space and time. NASA has designated RBSP as a risk class C mission (Explanation of risk classifications for NASA payloads, can be found in NPR 8705.4, Appendix A). As a result, the pair of spacecraft (including the instrument sui tes) are designed to be largely single-string. However, there is a fair amount of functional redundancy implemented within the overlapping performance characteristics of the science payload. Various instruments´ spectra provide surrogate measurements while others have inherent dependencies that need to be modeled across various phases of the mission. This paper discusses how the science objectives for full and partial mission success requirements are mapped in the Probabilistic Risk Assessment (PRA) to show a more accurate robust risk picture for the mission.