Quantitative comparison of single, three and six degree of freedom space structures vibration testing

This study analyzes the impact of rotational degrees of freedom on spacecraft acceleration and stress, comparing sequential single/tri-axis testing with simultaneous six-axis tests. Findings indicate that tri-axis testing can closely simulate six-axis results, even for structures off-center from the launcher axis. The research addresses that while launcher transients are predominantly longitudinal, mounting space hardware away from the central axis can increase rotational components. Furthermore, it highlights that standard single-axis testing often leads to unavoidable over-testing, failing to fully account for the complex, multi-axis nature of the launch environment.