返回舱/空间探测器热防护结构发展现状与趋势

针对中国天地往返和深空探测领域对热防护结构的需求，综述了国内外返回舱和空间探测器热防护材料/结构的发展现状，着重介绍了包括蜂窝增强热防护材料、纤维增强热防护材料、组合式热防护结构以及展开式热防护结构等在内的代表性热防护材料/结构的设计理念和性能特征。在系统总结热防护结构发展趋势的基础上，分析了返回舱和空间探测器热防护结构发展中存在的关键问题，可以看出：纤维增强热防护材料在热防护结构重量方面表现出了突出优势，材料拼接设计成为结构发展的重要阻碍；组合式热防护结构设计在现有材料发展水平的基础上，将成为提高热防护结构效率的有力途径；展开式热防护结构有望使航天器有效载荷重量显著提升，但受限于柔性热防护材料性能和结构工艺，仍有待发展。更加频繁的天地往返运输和深空探测项目的开展必将对热防护结构发展产生巨大的推动作用。

Development status and trend of thermal protection structure for return capsules and space probes

In view of the demand of thermal protection system for China space transportation system and deep space exploration, domestic and international studies on development and status of thermal protection materials and structures for return capsules and space probes are reviewed, focusing on the design idea and the performance characteristics of representative materials and structures including honeycomb reinforced thermal protection materials, fiber reinforced thermal protection materials, combined thermal protection structures, and deployable thermal protection structures. On this basis, the development tendency and obstacles of the materials and structures are analyzed, showing that fiber reinforced thermal protection materials have predominance in structural weight and the seam design is the important obstacle to the corresponding structure development. Moreover, on the basis of existing materials, the combined thermal protection structure design is becoming an effective method for improving the efficiency of thermal protection structure. The deployable thermal protection structures are expected to significantly enhance the payload of spacecraft; however, the flexible thermal protection materials still need to be developed. Generally, more frequent space transportation and development of deep space exploration will play an important role in promoting the development of thermal protection structures.