TPF-C Technology Plan - Exoplanet Exploration Program - NASA

Chapter 5
5.6.1 Modeling Methodology Validation
Because TPF-C cannot be fully tested on the ground, successful implementation of the mission
requires that models accurately predict sub-nanometer level performance prior to launch,
currently beyond the state-of-the-art. TPF-C will address model development as “software
fabrication” by including additional margin in the error budget to account for modeling
uncertainties or tolerances much as is done for hardware fabrication. This implies that the
accuracy of the prediction will be quantified by tracking contributions to the modeling errors
during the project lifecycle. In effect, the TPF-C modeling validation is now treated as validation
of analysis bounds, where the uncertainty is quantified and managed by the error budget.
Through the use of the modeling error margins, we will derive rational and consistent acceptance
criteria for the validation and delivery of models.
5.6.2 Error Budget Validation through Modeling
A systematic approach will be used to identify which error budget terms, starting from Level 2
requirement levels on down, will be validated by analysis and which will be directly validated by
tests. Each of the models, parameters and assumptions used for validating the error budget
terms, will then need to be validated themselves through a series of tests or testbed results,
starting from the lowest level of assembly on up. Validation of TPF-C models will fall in one of
two categories, validation of absolute predictive accuracy and validation of relative predictive
accuracy. In either case, the approach implemented on TPF-C will require that validated
accuracy be bound by the modeling uncertainties.
Table 5-5. M&MV Technology Validation vs. Testbed Matrix
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