A quantitative evaluation approach to astronaut safety of manned spaceship

Astronauts´ safety is the primary factor to evaluate whether manned spacecraft satisfies the qualification of manned space flight. Based on the definition of astronaut safety given by NASA, a quantitative evaluation approach to astronaut safety has been put forward and established. An example about astronaut safety of manned spaceship has been calculated, which has combined the system reliability and the conditional probability of survival given a system failure. The method also has made it easy to prioritize the risk drivers including the main systems and emergency subsystem which contribute to the risk of loss of astronaut.