前言航天事业的发展是促进低温技术发展的动力.首先,航天器必然要在低温环境下工作.航天器被运载火箭送入地球大气层外的预定轨道后,便在深冷(3～4K)、高真空的环境中飞行。为了确保航天器安全可靠地完成预 Preface The development of aerospace industry is the driving force to promote the development of cryogenic technology.Firstly, the spacecraft must work in low temperature environment.After the spacecraft is launched into the orbit outside the Earth’s atmosphere by the carrier rocket, Flying in a high-vacuum environment. In order to ensure the safety and reliability of the spacecraft to complete the pre-