Nasa set to launch Perseverance rover and mini helicopter on Mars
美國準備向火星發射「毅力」號漫遊者和迷你直升機

Most sophisticated vehicle ever sent to red planet will search for signs of life and prepare way for human visits
送往火星的最先進的飛行器將尋找生命跡象，併爲人類的訪問做準備。