Leakage performance of rubber seal is a key factor of spacecraft system, which is required long life. But the degradation law of the rubber seal performance in long service period is limited to qualitative analysis for its macro contact performance, and the quantitative research of rubber seal leakage performance is rarely involved considering thermal oxygen aging effect. Therefore, the thermal oxygen aging mathematical model is firstly established to predict the life of rubber material by aging tests. Secondly, the finite element model (FEM) of rubber seal performance analysis considering thermal oxygen aging effect is built to obtain the degradation law of its macroscopic contact performance with the increase of service time. Thirdly, the micro-leakage model of rubber seal considering thermal oxygen aging effect is established based on the material surface microstructure, contact pressure, and contact width, and the leakage rate of rubber seal is calculated by the model. Finally, the micro-leakage model of rubber seal is modified based on the experimental results, so the calculation accuracy of leakage rate is improved.

For the manned International Space Station, the more stringent requirements of the leakage performance of the rubber seal, which is located in it, is presented. The leakage is caused by the small leakage paths between contact pairs of the rubber seal. Therefore, it is necessary that the micro-leakage performance analysis between interfaces of the rubber seal is carried out. Based on this, the finite element model (FEM) of macroscopic contact performance analysis of the rubber seal is established first, and the macroscopic contact pressure and contact width of the rubber seal are calculated by the model. Then, the micro-leak path model is constructed based on the contact width and surface micro-structure, and the cross-sectional area of the micro-leakage path is obtained, when the contact pressure is acted on the model. Therefore, the fluid flow states in the micro-leakage path are determined, and the flow conductance and the seal leakage rate of rubber seal are all calculated. Finally, the micro-leakage model of the rubber seal is modified to improve the theoretical calculation accuracy by the experiment.