We can only lift so much mass off the Earth
我们只能从地球发射一定质量的物体
and have it land safely on Mars.
并使其在火星安全降落
The rover is five times as heavy as any vehicle
火星车的质量是过去发射过的
they've ever launched,
任何探测器的五倍
which makes landing it on another planet
这令它在另一行星的着陆
more difficult than anything they've attempted before.
比以前的任何计划都更加困难
Landing a big rover is a tough business.
大型火星车降落是一项艰巨的任务
The landing system is more complex,
需要更复杂的降落系统
parachutes are bigger,
更大的降落伞
everything gets much bigger and therefore harder.
一切都变大了所以也变困难了
NASA's engineers have never shied away
美国宇航局的工程师决不会屈服于
from tricky landings.
任何艰难的着陆
During the Apollo missions of the 1970s,
在七十年代的阿波罗登月计划期间
they weren't satisfied just to put a man on the moon.
他们已不满足于仅仅把人类送上月球
But landing a car on Mars
但让火星车在火星着陆
is an entirely different proposition.
完全是另一码事

重点解释：

1.put on 放上

例句：The old man put on his spectacles and started reading.
老人戴上眼镜开始看书。

2.so much 这么多

例句：He is not so much a genius as a hard worker.
他的努力胜于天分。