Nesc independent verification of SLS ascent static-aeroelastic and buffet loads the NASA engineering and safety center (nesc) will perform an independent verification (IV) of the space launch system…

This is a federal contract award by the National Aeronautics and Space Administration (NASA) to The Aerospace Corporation, a non-profit organization, to perform an independent verification (IV) of the Space Launch System (SLS)/Multi-Purpose Crew Vehicle (MPCV) ascent structural responses and loads. The $159,616 contract is a cost-plus-fixed-fee delivery order that focuses on verifying the static-aeroelastic and buffet loads analysis methodologies used by NASA/MSFC and Dynamic Concepts Incorporated to compute SLS loads. The work builds on a previous NESC technical assessment and will independently compute loads to assess and verify the methodologies, which will complement independent turbulence/gust loads analyses. This is not associated with a set-aside contract vehicle.

Nesc independent verification of SLS ascent static-aeroelastic and buffet loads the NASA engineering and safety center (nesc) will perform an independent verification (IV) of the space launch system (SLS)/multi-purpose crew vehicle (mpcv) ascent structural responses and loads. The SLS marshall space flight center (msfc) integrated loads team is using a combination of fortran matrix analysis, an internal NASA msfc code for model coupling, and proprietary dynamic concepts incorporated (DCI) matlab codes to perform the ascent response calculations and output transformation matrices (OTM) processing, the results of which are delivered to the mpcv program and SLS integrated spacecraft payload evolution upper, core, and booster stage elements. These implementations have received only a cursory independent verification by the exploration systems development (ESD) program-to-program team in the past, and the peer review team for task TI-16-01110 has noted and documented modeling discrepancies that merit further, deeper assessment. Rather than immediately assessing the entire ascent flight regime across all ascent mach numbers, this plan takes an incremental approach, building on nesc technical assessment TI-16-01128 and first checking the modeling, system dynamic coupling, response calculation, and OTM development and recovery for the transonic and maximum dynamic pressure (max q) regimes. Independent loads will be computed to assess/verify the static-aeroelastic and buffet events methodologies, which will complement the independent turbulence/gust loads analyses nearing completion. Proceeding to other flight regimes will occur only as approved by the nesc review board (NRB) in a subsequent phase after review of initial phase results and recommendations. The purpose of this task is to verify the static-aeroelastic and buffet loads analysis methodologies being used by NASA /msfc and DCI to compute SLS loads. Loads will be computed using the same models, OTM recovery matrices, aerodynamic data, and forcing functions used in the NASA /msfc and DCI calculations. The computed loads will be compared to those computed by NASA /msfc and DCI. The task will not include reconciliation of differences in computed loads and noted element limits or redlines, or assessment of resulting structural margins of safety, with the cognizant element structures teams. However, this assessment will perform a reconciliation effort to resolve fundamental OTM formulations and implementation differences, if any. Such additional work, if warranted, will be coordinated and planned with ESD and the cognizant program(s) and element(s) before returning to the ESD and NRB for approval to proceed.