When people look at it, uh, it looks crazy. That's a very natural thing. Sometimes when we look at it, it looks crazy. It is the result of reasoned, engineering thought. But it still looks crazy.
當人們注視它的時候,啊,它看起來很瘋狂。那是理所當然的。有時候連我們自己看它,它都顯得很瘋狂。它是深思熟慮、工程思維的結果。但它仍然看起來很瘋狂。
From the top of the atmosphere, down to the surface, it takes us seven minutes. It takes fourteen minutes or so, for the signal from the spacecraft to make it to Earth. That's how far Mars is away from us. So when we first get word that we've touched the top of the atmosphere, the vehicle has been alive, or dead, on the surface, for at least seven minutes.
從大氣層頂部,一直降到(火星)表面,要花上七分鐘。從太空船上傳送訊號到地球要花上十四分鐘左右。那就是火星和我們的距離。所以當我們第一次收到訊息說我們已經接觸到大氣層頂端時,太空船已經在(火星)表面存活或是陣亡至少七分鐘了。
Entry, descent and landing, also known as EDL, is referred to as the "Seven minutes of terror". Because we've got literally seven minutes to get from the top of the atmosphere to the surface of Mars, going from thirteen thousand miles an hour to zero, in perfect sequence, perfect choreography, perfect timing, and the computer has to do it all by itself, with no help from the ground. If any one thing doesn't work just right, it's game over.
進入、下降和著陸,又名EDL,被稱之為「恐怖的七分鐘」。因為我們實質上從大氣層頂部到火星表面要花上七分鐘,從每小時一萬三千英里(兩萬零八百公里)到零,以完美的程序、完美的編排,完美的時間掌控,而電腦必須全部自己完成,沒有來自於地球的協助。如有任何一件事情出差錯,遊戲就玩完了。
We slam into the atmosphere and develop so much aerodynamic drag. Our heat shield, it heats up, and it glows like the surface of the sun, sixteen hundred degrees. During entry, the vehicle is not only slowing down violently through the atmosphere, but also we are guiding it like an airplane, to be able to land in a very narrow constrained place. This is one of the biggest challenges that we are facing, and one that we have never attempted on Mars.
我們猛然衝進大氣層並產生極大的空氣阻力。我們的隔熱護盾產生高溫,發出像太陽表面一樣的光芒,有一千六百度。在進入的過程中,太空船不但急劇減速穿越大氣層,我們也像是對飛機一般的引導它,使它可以著陸在一個非常狹窄且受限制的地點。這是我們面對最大的挑戰之一,也是我們從未在火星做過的嘗試。
Mars. It's actually really hard to slow down, because it has just enough atmosphere. That you have to deal with it, otherwise, it will destroy your spacecraft. On the other hand, it doesn't have enough atmosphere to finish the job.
火星。其實減速是很困難的,因為它僅有些微的大氣。你必須去處理它,否則它會摧毀掉你的太空船。換言之,它沒有足夠的大氣層來完成任務。
We're still going about a thousand miles an hour. So at that point we use a parachute. The parachute is the largest and strongest super-sonic parachute that we've ever built to date. It has to be able to withstand sizty-five thousand pounds of force, even though the parachute itself only weighs about a hundred pounds. When it opens up that fast, it's a neck-snapping 9G's.
我們仍然以約每小時一千英里(一千六百公里)的速度前進。所以在那階段我們使用降落傘。這降落傘是我們至今所建造過最大且最強韌的超音速降落傘。即使降落傘本身只重約一百磅(四十五公斤),它必須能夠承受六萬五千磅(約三萬公斤)的力量。當它如此之快的展開時,那是會折斷脖子之9G的重力加速度。
At that point, we have to get that heat shield off. It's like a big lens cap, blocking our view of the ground to the radar. The radar has to take just the right altitude and velocity measurements at just the right time, or the rest of the landing sequence won't work.
那時,我們必須拋棄隔熱護盾。它就像是個大型鏡頭蓋,阻擋我們從雷達看到地面的視線。雷達必須要在正確的時間,測量出正確的高度和速度值,否則剩餘的降落程序將不會成功。
This big huge parachute that we've got, will only slow us down to about two hundred miles an hour. That's not slow enough to land. So we have no choice that we've got to cut it off, and then come down on rockets. Once we turn those rocket motors on, if we don't do something, we're just gonna smack right back into the parachute!
我們所擁有的這個大型降落傘,只能把我們減速至大約每小時兩百英里(三百二十公里)。那樣不夠慢得足以降落。所以我們別無選擇,而必須丟下它,然後用火箭下降。一旦我們啟動那些火箭引擎,如果我們不做些應變措施,我們就會立刻衝回降落傘中。
So the first thing we do is make this really radical "Divert Maneuver". We fly off to the side, diverting away from the parachute, killing our horizontal velocity and our vertical velocity, getting the rover moving straight up and down, so it can look at the surface with its radar, and see where we're going to land, and we head straight down to the bottom of a crater, right beside a six kilometer high mountain.
所以我們所做的第一件事就是做這非常極端的「轉向動作」。我們往旁邊飛去,離開降落傘,消除掉我們的水平速度和垂直速度,讓探測小艇上下移動,如此一來它可以使用雷達來探測表面,看看落陸地點,然後我們垂直下降到隕石坑底部,就在一座六公里高山的旁邊。
We can't get those rocket engines too close to the ground. Because if we were to descent propulsively, our engines all the way to the ground, we would essentially create this massive dust cloud. That dust cloud could then go on land on the rover. It could damage mechanisms, and it could damage instruments. So the way we solve that problem, is by using the skycrane maneuver.
我們不能讓那些火箭引擎太靠近地面。因為如果我們要用火箭引擎推進下降,一路到地表,現實中會產生巨大的塵雲。那塵雲會接著落到探測小艇上。它可能會傷害機械結構,而且可能會損毀儀器。所以我們的解決問題之道是,使用空中吊車操作。
Twenty meters above the surface, we have to lower the rover below us on a tether that's twenty-one feet long. And then gently deposit it, on its wheels, on the surface. As the rover touches down and is now on the ground, the descent-stage, is on a collision course with the rover. We must cut the bridle immediately and fly the descent-stage to a safe distance from the rover.
在地表二十公尺高處,我們必須要用二十一英尺(6.5公尺)長的繫繩降下底下的探測小艇。然後輕柔地將它,四輪著地式的,安放在地表。當探測小艇著陸時,降落平台卻在會撞上探測小艇的路線上。我們必須立刻切斷繫船索並將降落平台飛到與探測小艇保持安全距離的地點。