There is still a significant gap in currentpropulsion technology and what may be needed for an interstellar mission.
我们现有的推进技术和我们需要的应用于星际飞行的推进技术仍然有很大的差距。
2
In its current structure, the 12 chapters cover all aspects of shipping from construction and fire protection to nuclear propulsion, dangerous cargo, safety management and maritime security.
在其目前的结构，这12章涵盖了从建筑和防火运到核推进，危险货物，安全管理和海事安全的各个方面。
3
It points out that under current situation, the optimum design of electric propulsion ship's central cooling system will raise the reliability and economy of system operation.