信标必须安置在指定的着陆点。

Beacon must be placed in the designated LZ.

拉勒认为较低的轨道有利于更好地考察未来的着陆点。

A low orbit will allow for better scouting of future landing sites, said Lele.

现在科学家们正在着手建造下一代的火星探测器，但在火箭升空之前，研究者们还要在火星上挑一个着陆点。

Now, scientists are building the next rover to be sent to Mars. But before they fuel the rockets, researchers have to pick a spot to explore.