Since the late half of this century, penetrators have been considered as landers on these bodies.

近半个世纪以来，人们一直在筹划使用侵彻器在这些星体着陆。

The specific kind of composite targets can only have good defence effect for the long rod penetrators with certain velocity.

特定组成成分的陶瓷复合装甲只对一定速度范围内的侵彻体有较好的防御效果。