CNN News:美国"毅力号"火星车成功登陆火星

A rover that launched last July 30th was scheduled to arrive on Mars yesterday and scientists were hoping that the Perseverance mission would help them figure out if life was ever present on the red planet.
The mission's cost is $2.7 billion. It was scheduled to last two years. If all goes as planned during that time, the Perseverance rover is set to travel 15 miles studying Mars' climate and geology and collecting samples of Martian soil that could one day be brought back to Earth, if another mission succeeds in sending a spacecraft to pick them up.
But we're getting ahead of ourselves. The rover first had to undergo an extensive check out period, a kind of booting up on Mars. It had to unfold and download software. It's got to deploy a $23 million drone helicopter who's purpose is to find out if powered chopper flight is possible on Mars. And before any of that can happen, Perseverance had to make a safe landing on the red planet.

But as you heard a moment ago, getting the rover down safely is the tricky part. Mars is about 127 million miles away from Earth right now. It takes 11 minutes for radio signals to travel from Earth to Mars and the Perseverance rover landing process was set to happen over seven minutes.
That's why it had to happen autonomously without scientists manually making adjustments on its way down. Yesterday evening, NASA said that Perseverance appeared to land safely on the red planet. Various spacecraft at NASA and the European Space Agency had in orbit over Mars were set to fly over the rover and check up on its health.