NASA將向火星發射直升機，拍攝火星鳥瞰圖！
NASA announced this afternoon that it plans to launch a tiny, four-pound, autonomous helicopter along with its 2020 rover mission. And if you think this sounds relatively cool, well: you're right.
今天下午美國國家航空暨太空總署(NASA)擬送微型、約四磅（3.6斤）的無人直升機完成2020年的火星探測任務，如果你覺得聽起來很酷，那就對了。
The experimental, softball-sized drone would be the first airborne vehicle to fly around within Mars's atmosphere other than the landers that have delivered other, ground-based rovers.
這架壘球大小的實驗無人機，不同於之前送到火星地表上探測儀，它被直接送到火星的大氣層。
In order to design a flying vehicle that would actually work on another planet, NASA scientists faced a number of chanllenges.
爲了使這家飛行器真正能夠在火星上運行，NASA的科學家面對了一系列的挑戰。
For example: the Red Planet's particularly-weak atmosphere and the communication delay between ground control here on Earth and the rover.
比如，火星的大氣層非常的薄，而且探測器和地球上的控制溝通會有所延時。
Traveling at the speed of light, it'll still take several minutes for any commands sent from Earth to reach the helicopter, so the flying rover will have to be at least partially autonomous as it provides scientists and other autonomous vehicles with the first long-term bird's-eye view of the planet.
儘管傳遞速度是光速，從地球上發射出的信號到達探測器的時候還是需要好幾分鐘，所以該探測器半自動化地向科學家和其他自動儀器長期提供火星鳥瞰圖。
Also, the Martian atmosphere is practically non-existent. The air pressure at the planet's surface is lower than it is at a helicopter's maximum altitude when flying above Earth.
加之，火星的大氣層幾乎沒有存在感，大氣層的高度比探測機的垂直高度比在地球飛行時的最大值還要低。
In order to take off, the tiny flying robot needs to spin it's two blades ten times faster - 3,000 times per minute - than it would on Earth while carrying batteries and other hardware crafted to be as light as possible.
所以哪怕是飛行器裝載最輕的電池和硬件設備起飛，兩個螺旋槳的也要比地球起飛時轉速快10倍，達到每分鐘3000轉。
When the rover arrives at Mars in February 2021, it'll perform scouting missions to look for ideal landing zones on the surface, as well as scan the planet for signs of life, hazards that might matter to the future astronauts who finally venture to Mars.
預計2020年2月到達火星，通過在火星上完美着陸來完成初步勘察工作，探查在火星上是否有生命存在跡象，以及未來宇航員登陸火星有什麼危險因素等問題。
It'll also assist with the ongoing geology research currently underway by ground-based rovers.
它還會協助現有陸地探測器來完成地理研究。
