To exactly estimate the reliability of reusable rocket engine
a Boolean algebra with restriction on variables was introduced to properly combine fault tree analysis with state analysis
and the reliability analysis of complex multistate system with statistically depent components were performed. Both the multistate of pipes and the statistical dependence between preburner and turbopump of space shuttle main engine (SSME) were deeply studied. The result show that the Boolean algebra can well eliminate statistical dependence among components to simplify the fault tree analysis of complex multistate system
and the statistical dependence has significant influence on the system reliability
so further research is required for higher performance of the reusable rocket engine.