because the demand of construction, weight, electric power and electronics system, a lot kinds of dielectrics be used in spacecrafts. some dielectrics had to be exposed directly in space environment.
由于结构、重量、电能及电子系统的要求,航天器上要用到大量的介质材料,某些介质材料还必须直接暴露于空间环境之中。