本手册的这一部分介绍了解决航天器机载设备环境控制问题的方法。该问题的温度方面可定义为维持以下热负荷的适当平衡和整合:产生的设备、产生的人员和通过外部边界的传输。实现这种热能平衡需要研究三个具体领域:1。确定设计要求；2.材料性能的评估；分析方法的发展。车辆和/或设备增压问题的解决方案是主要环境控制功能的后半部分，本节也将讨论该问题。在这种情况下，增压可定义为与增压流体的储存和控制、泄漏控制和再增压相关的任务。 尽管压力控制的功能仅次于热能平衡，但它仍然是整个环境问题的一个重要方面。环境控制系统（ECS）必须在与太阳、地球和太空不断变化的辐射热能交换条件下运行，并具有可变的内部设备负荷。通常情况下，在运行阶段，必须从具有较小外表面的小部件中耗散集中的能量。内部产生的热负荷可能是周期性的，但相对于轨道而言也是随机的。一些设备，如执行器、姿态控制装置或储罐可能部分暴露，需要特殊处理。只有在加压的情况下，其他部件才能正常工作，而在某些情况下，加压是一种消除在硬真空中进行鉴定的方法。 这些安装技术将引入其自身的热控制问题，并有助于选择特定的ECS配置。

This part of the manual presents methods for arriving at a solution to the problem of spacecraft inflight equipment environmental control. The temperature aspect of this problem may be defined as the maintenance of a proper balance and integration of the following thermal loads: equipment-generated, personnel-generated, and transmission through external boundary.Achievement of such a thermal energy balance involves the investigation of three specific areas: 1. Establishment of design requirements; 2. Evaluation of properties of materials; and 3 development of analytical approach.The solution to the problem of vehicle and/or equipment pressurization, which is the second half of major environmental control functions, is also treated in this section. Pressurization in this case may be defined as the task associated with the storage and control of a pressurizing fluid, leakage control, and repressurization. Although secondary to the thermal energy balance, the function of pressure control is nevertheless an important aspect of the overall environmental problem.Environmental control systems (ECS) must operate in a continuously changing radiant thermal energy exchange condition with the Sun, Earth, and space, and with variable internal equipment loads. Frequently, during the operational phase, concentrated amounts of energy must be dissipated from small components with small external surfaces. The internally generated heat loads may be cyclic but also random with respect to the orbit.Some equipment such as actuators, attitude control devices, or storage tanks may be partially exposed and require special treatment. Other components will function properly only if pressurized, while in some instances pressurization is used as a means of eliminating the need for qualification in a hard vacuum. These installation techniques will introduce their own thermal control problems and contribute to the selection of a specific ECS configuration.