纪录片《火星任务》 第7期 安全降落

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 tricky¹ 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 entirely² different proposition.

完全是另一码事

1 tricky   

adj.狡猾的，奸诈的；(工作等)棘手的，微妙的

参考例句：

• I'm in a rather tricky position.Can you help me out?我的处境很棘手，你能帮我吗？
• He avoided this tricky question and talked in generalities.他回避了这个非常微妙的问题，只做了个笼统的表述。

2 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。