Analysis and Performance Reconstruction of VEGA Solid Rocket Motors Qualification Flights

VEGA is the launch vehicle developed by the European Space Agency, qualified with its first two maiden flights on February, 13rd 2012 and on May, 7th 2013 and recently delivered to the commercial market with the third flight held on April, 30th 2014. During the launcher development, a total of eight static firing tests have been performed for the three solid stages, which compose the launcher: the first stage P80, the second stage Zefiro 23 and the third stage Z9. In this work, the analysis and performance reconstruction of the solid rocket motors of the VEGA launch vehicle for the two qualification flights is carried out with a post-firing reconstruction model, developed for the purpose. The aim is to use the measures acquired during the flights and the experience gained from the static firing tests analysis, in order to evaluate the actual behavior of the VEGA solid stages, through the non-ideal parameters: combustion efficiency, thrust efficiency, hump, scale factor and nozzle throat erosion law, which define the actual performance parameters of the solid rocket motors. The purpose of the work is to assess the SRMs performance parameters from the flight data, comparing the outcomes of the flight data analysis with the ones provided by the static firing test data analysis. The final aim is to consolidate the methodology for the analysis and reconstruction of the solid stage flight data, in order to define/characterize the scattering of the motor performance, reducing the uncertainties for the prediction methodologies in the upcoming and following VEGA flights.