Digital simulation on reusable liquid rocket engine availability

The reusable liquid rocket engine (RLRE), which can reduce the space launch cost, is one of the future spacecraft development directions. It is difficult to assess the RLRE availability for its complexity, differences of the component life model and other uncertain factors. As an example, the availability of space shuttle main engine (SSME) high-pressure fuel (hydrogen) Turbopump (HPFTP) was analyzed using Monte Carlo simulation technology based on the historical data of SSME. The method, taking into account the impact of early maintenance on the later maintenance, did not involve the life distribution model of components, and can reasonably simulate the process of system failure occurrence. The results show that under incomplete maintenance the mean best reasonable preventive maintenance time of HPFTP is 6340 s, it can be reused theoretically 12 times for satisfying the mission requirement of the space shuttle, and the corresponding mean best availability is 0.285. The availability of HPFTP is low due to its severe working process. This study provides a reference for studying the aerospace propulsion reusability.