Space Policy Directive-3 lays out general guidelines for the United States to mitigate the effects of space debris and track and manage traffic in space.
2019年6月六級真題（第二套）閱讀 Section C
柯林斯高階英漢雙解學習詞典釋義
VERB
減輕;緩解;緩和
To mitigate something means to make it less unpleasant, serious, or painful.