Verker Ronen, Grossman Eitan, Gouzman Irina
Space Environment Department, Soreq NRC, Yavne, Israel.
Rev Sci Instrum. 2011 Feb;82(2):023901. doi: 10.1063/1.3529878.
The low Earth orbit (LEO) environment is considered hazardous to spacecraft, resulting in materials degradation. Currently, in order to evaluate the degradation of materials in LEO, a retrieval of space exposed samples is required. In this study, a novel approach is proposed to evaluate degradation of materials in LEO without the need of retrieval. The method is utilizing photovoltaic cells (PVCs), an existing component onboard of any satellite. The PVCs are coated by various materials which are sensitive to different LEO constituents, such as atomic oxygen (AO) or ultra-violet (UV) radiation. The method's acronym is ORMADD (on-ORbit MAterials Degradation Detector). The ORMADD's principle of operation is based on measuring the PVC output power which depends on the cell coating material's optical transmission. Erosion of the coating by AO or coloring due to UV radiation affects its optical transmission and, accordingly, the PVC output. The ORMADD performance was tested using different coatings, such as polyimide and amorphous carbon (sensitive to AO), and siloxane based coating which is sensitive to UV radiation. The proposed ORMADD reveals sensitivity to different LEO components and can be used either as material degradation detector or as an AO monitor.
近地轨道（LEO）环境被认为对航天器有害，会导致材料降解。目前，为了评估LEO中材料的降解情况，需要取回空间暴露样本。在本研究中，提出了一种无需取回样本即可评估LEO中材料降解的新方法。该方法利用光伏电池（PVC），这是任何卫星上现有的组件。PVC由对不同LEO成分敏感的各种材料涂覆，例如原子氧（AO）或紫外线（UV）辐射。该方法的首字母缩写是ORMADD（在轨材料降解探测器）。ORMADD的工作原理基于测量PVC输出功率，该功率取决于电池涂层材料的光传输。AO对涂层的侵蚀或UV辐射导致的着色会影响其光传输，进而影响PVC输出。使用不同的涂层测试了ORMADD的性能，例如聚酰亚胺和非晶碳（对AO敏感），以及对UV辐射敏感的硅氧烷基涂层。所提出的ORMADD对不同的LEO成分具有敏感性，既可以用作材料降解探测器，也可以用作AO监测器。
