land on the red planet but it isn't alone the  united arab emirates hope orbiter and china's  

在紅色星球上登陸，但它並不孤單 阿拉伯聯合酋長國希望軌道飛行器和中國的

tien1 mission have already arrived at mars orbit  and it's been seven months since they took off  

天天1號任務已經抵達火星軌道 距離它們起飛已經有7個月了。

but for mars 2020 and tien when one one  of the hardest parts is still yet to come  

但對於火星2020年和天時，最困難的部分之一仍未到來。

actually sticking the landing on the red planet  fondly known as the seven minutes of terror  

實際上，在紅色星球上的著陸被稱為 "恐怖的七分鐘"。

it takes about seven minutes from the time that  the spacecraft first comes in contact with mars  

從航天器首次接觸火星開始，大約需要7分鐘的時間

of atmosphere until we get down to the ground  and the terror part comes in um because you know  

大氣層，直到我們下到地面，恐怖的部分就來了 嗯，因為你知道

all of that stuff is difficult there are so many  things that can go wrong as you're landing on mars  

所有這些東西都很困難 當你在火星上著陸時，有很多事情可能會出錯。

this part of the mission is known as the entry  descent and landing or edl and it all starts  

這部分任務被稱為進入下降和著陸或EDL，這一切都開始了。

with the spacecraft hurtling through the martian  atmosphere at roughly 20 000 kilometers per hour  

航天器以大約每小時2萬公里的速度在火星大氣層中飛行

causing the external heat shield to heat up to  around 1300 degrees celsius with some help from  

導致外部隔熱罩在一些幫助下升溫至1300攝氏度左右。

its heat shield the vehicle slows down to about  1600 kilometers per hour and this is when its  

車輛減速到時速1600公里左右，這時它的隔熱罩

supersonic parachute deploys the heat shield then  pops off but the parachute doesn't slow the rover  

超音速降落傘展開隔熱罩，然後彈開，但降落傘並沒有減緩漫遊車的速度。

down enough for a safe landing the main reason for  this is because of mars thin atmosphere it's about  

這主要是因為火星大氣層稀薄的緣故

one percent as dense as earth's atmosphere but  not enough to really help you a lot once we end  

密度只有地球大氣層的百分之一 但不足以真正幫助你，一旦我們結束了

up deploying our parachute to help us land safely  the atmosphere doesn't actually slow us down that  

我們的降落傘是為了幫助我們安全著陸 大氣層其實並沒有讓我們的飛行速度變慢

much and so we end up having to get rid of that  parachute and come down the rest of the way  

所以我們最終不得不擺脫降落傘，從剩下的路上下來。

using rockets these eight retro rockets located on  the descent stage help to slow down the craft the  

使用火箭 這八枚位於下降級的復古火箭有助於減緩飛行器的速度。

vehicle then performs a divert maneuver to avoid  coming into contact with the discarded parachute  

然後，飛行器執行一個轉向動作，以避免接觸到廢棄的降落傘。

and finally about 20 meters from the surface  the descent stage lowers the rover using cables  

最後，在距離地面20米左右的地方，下降階段使用電纜將漫遊車降低。

where perseverance unlocks its legs and wheels for  the final touchdown and so all of this just adds  

在那裡，堅持不懈地釋放它的腿和輪子的最後觸地，所以這一切只是增加了

to the complicated nature of the systems that we  need to build to get us safely down to the ground  

複雜的系統的性質，我們需要建立一個系統，讓我們安全地降落到地面。

and one of the many crucial parts of this system  is the terrain relative navigation or playfully  

而這一系統的許多關鍵部分之一就是地形相對導航，或者戲稱為 "地形導航"。

referred to by the team as the spacecraft's  eyes this will be the first time that a nasa  

被該團隊稱為航天器的眼睛，這將是美國國家航空航天局的第一次。

rover will be able to actually see where it's  landing its onboard camera will snap pictures  

漫遊車將能夠實際看到它的著陸點 它的車載攝像頭將拍下照片。

of the surface's features to match them to its  onboard map and divert its course to pick the  

的地表特徵，將其與機載地圖相匹配，並改變其航向，以選取最適合的地表特徵。

best possible landing zone so now you know we can  reach that spot with an accuracy of about 30 to  

最佳著陸區，所以現在你知道我們可以準確地到達那個地方，大約30到40分鐘。

40 meters and it really opens up the door to the  planetary scientists to pick really interesting  

40米，它真的為行星科學家們打開了一扇門，讓他們挑選真正有趣的

spots to land is it that the geologists  tend to like interesting rough spots on mars  

落腳點是不是地質學家們都喜歡火星上有趣的粗糙點？

and those tend to be dangerous to land in  if successful perseverance will be the fifth  

而這些往往是危險的落腳點，如果成功堅持下去，將是第五個

nasa rover to safely reach the martian  surface but it's up against some pretty  

美國宇航局的探測器安全到達火星表面，但它面對的是一些漂亮的

tough odds as only forty percent of all  missions sent to mars have been successful  

困難重重，因為只有百分之四十的火星任務是成功的。

hoping to also beat those odds is china's tienwen1  spacecraft it recently just entered mars orbit on  

希望也擊敗這些機會的是中國的天文一號飛船 它最近剛剛進入火星軌道，在

february 10th and it's quite an ambitious first  attempt to reach the planet since the mission is  

2月10日，它是一個相當雄心勃勃的第一次嘗試 到達地球，因為該任務是

composed of three parts an orbiter a lander and  a rover the orbiter has already started imaging  

由三部分組成 一個軌道器 一個著陸器和一個巡視器 軌道器已經開始成像了

the future landing locations for its lander and  rover which will eventually descend to the surface  

其著陸器和漫遊車未來的著陸地點，這些漫遊車最終將下降到地面。

this anticipated landing won't happen until  may and last but not least there's the uae's  

這個預期的登陸要到5月才會發生 最後但並非最不重要的是，還有阿聯酋的。

first ever interplanetary probe called hope  which arrived on february 9th this starts  

第一顆星際探測器 "希望 "號於2月9日抵達，這就開始了。

a roughly two-year journey to capture the most  complete picture of the red planet's atmosphere  

大約兩年的旅程，捕捉到了紅色星球大氣最完整的畫面

it hopes to answer some crucial questions  like how exactly gases escaped the atmosphere  

它希望能回答一些關鍵性的問題，比如氣體究竟是如何從大氣中逃逸出來的。

a question that has long since puzzled scientists  this is a thrilling time in mars exploration we  

這個問題一直困擾著科學家們 這是火星探索中一個激動人心的時刻

only have this opportunity every so often and so  when we get a chance we like to take advantage of  

機會難得，所以我們一有機會，就喜歡趁著

it and this moment is historic in itself with the  arrival of three separate missions to mars within  

而這一時刻本身就是歷史性的，在這一時刻，有三個獨立的火星任務到達了火星。

the span of just a couple weeks and for the mars  2020 team it'll be a bit of a nail-biter until  

僅僅幾個星期的時間，對於火星2020團隊來說，這將是一個有點釘子戶，直到。

february 18th when perseverance begins its final  descent to the surface so you can better believe  

2月18日，當毅力開始其最後的下降到表面，所以你可以更好地信任

that i'm going to be gripping my desk on february  18th and crossing my fingers that everything goes  

我要抓住我的辦公桌上2月18日 並穿過我的手指，一切都去。

just as we planned it and as we tested it so i'm  very excited for more countdown to launch check  

就像我們計劃和我們測試它，所以我很興奮更多的倒計時推出檢查

out this playlist here if there's another launch  that you want to see us cover let us know in the  

如果有其他的發佈會，你想看到我們報道，讓我們知道在這個播放列表。

comments make sure to subscribe and thank you  so much for watching i'll see you next time you

評論一定要訂閱，並感謝你這麼多的觀看，我會看到你的下一次你