生命保障系统是载人航天中使用的，为使人能够在外太空生存的一系列设备的总称。美国国家航空航天局的载人航天飞行中也常称之为环境控制与生命保障系统（ECLSS）。生命保障系统可以提供生存所需的空气、水和食物，并可以维持合适的身体温度与压力，同时可以收集或处理代谢中产生的废物。生命保障系统也必须能够屏蔽来自外部的有害影响，例如：射线和微星体。生命保障系统中的所有组件都是关乎生命，所以都是基于安全工程学进行设计。

In human spaceflight, a life support system is a group of devices that allow a human being to survive in space. US government space agency NASA, and private spaceflight companies use the term environmental control and life support system or the acronym ECLSS when describing these systems for their human spaceflight missions. The life support system may supply air, water and food. It must also maintain the correct body temperature, an acceptable pressure on the body and deal with the body's waste products. Shielding against harmful external influences such as radiation and micro-meteorites may also be necessary. Components of the life support system are life-critical, and are designed and constructed using safety engineering techniques.