Original subtitles

火星，红色星球。 Mars, the Red Planet.

千百年来，作为神话传说的对象， For millennia, an object of mystery,

充满阴谋和幻想。 intrigue and fantasy.

但现在不止如此。 But now it's more than that.

它是人类探索深空的下一个目标。 It's the next target in the human exploration of space.

这是令人兴奋的远景目标，但我们成功的可能性有多大？ It's a thrilling prospect, but how likely are we to succeed?

或者说这是我们应该尝试的旅程吗？ And is it a journey we should even be attempting?

拥有医学、天体物理学和航空学的职业生涯， With a career spanning medicine, astrophysics and aeronautics,

我们特别安排方凯文博士来探索这场不可思议的挑战 Dr Kevin Fong is uniquely placed to explore the incredible challenges

如何完成人类登陆火星的任务。 that a human mission to Mars would pose.

这将是人类有史以来最危险的远征。 This is going to be the most risky human expedition in the history of our species.

红色星球，火星。2000多年来，战神的象征。 The Red Planet, Mars. For over 2,000 years, the symbol for war.

现在，在BBC档案馆的帮助下… Now, with the help of the BBC's archive...

我们刚刚收到了一些由美国探测器发回的神奇图片 We've just had some amazing photographs sent back by the American probe

来自水手6号。 to Mars, Mariner 6.

凯文将探寻如果想成功，我们需要做什么。 ..Kevin is going to explore what we'll need to do if we are to succeed.

如果没有在低地球轨道上交汇对接的能力，这是不可能完成的。 It cannot happen without your ability to integrate stuff in low Earth orbit.

没有国际合作是不可能的。 It cannot happen without international cooperation.

这是一次考验技术和人类生存极限的旅程。 It's a journey that will test technology and human survival to their limits.

没有人知道这是否可能。 No-one knows if it's possible.

那种隔绝，孤立的感觉， That isolation, that feeling of isolation,

部分原因是由于通讯的延迟，会相当强烈。 partly because of the delay in communications, will be quite intense.

对于凯文来说，这是一场挑战技术极限的探讨， It's a debate that, for Kevin, pushes the limits of technology,

人类忍耐力的极限，并探索人类的 the extremes of human endurance and explores the very idea of what it is

本质。 to be human.

BBC：我们要去火星吗？

出发，阿特拉斯。出发，半人马座。 Go, Atlas. Go, Centaur.

我们正处于新一轮太空竞赛的初期。 We're in the early days of a new space race.

这次，目标是火星。 This time, the target is Mars.

但并不是俄罗斯和美国宇航局在比拼， But it isn't the Russians going toe to toe with Nasa,

而是私人航天公司进入太空的第一步。 it's private companies taking their first steps into space.

要论谁有资格去评论人类火星登月任务 No-one is better qualified to explore the challenge of our first

没有人比得上方凯文博士。 human expedition to Mars than Dr Kevin Fong.

他在美国宇航局受训工作， He's trained and worked with Nasa,

他研究了人类在极端环境中的生存能力 and he's researched human survivability in extreme environments to better

熟知人类太空任务的挑战。 understand the challenges of human space missions.

海拔的影响相当明显。 The effects of altitude are pretty obvious.

涵盖火星竞赛的进程， With the race to Mars well and truly under way,

凯文将剖析这样一个任务所面临的独特挑战， Kevin will dissect the unique challenges such a mission would face,

探索火星任务的推动力， explore the reasons for going,

遭遇反对人类火星任务的争论， encounter powerful arguments against a human mission to Mars and,

在观点冲突中，让他为人类有史以来最艰难的旅程辩护。 in so doing, make his case for the toughest journey humanity will have ever attempted.

失败的历史

火星吃掉飞船做早餐。

火星任务的第一个难题是发射记录对我们不利。 The first problem with Mars is that history is against us.

我们的无人探测器已经去过很多次了， Our robotic spacecraft have been there many times already,

结果完全是喜忧参半。 with decidedly mixed results.

半个多世纪以来我们一直往火星上发射探测器。 We've been firing stuff at Mars for more than half a century now.

第一次任务是在20世纪60年代。 The first missions went in the 1960s.

我们慢慢地建立起各种数据和档案 And we've slowly been building up this collage of evidence about what

火星是怎样的。 Mars is like.

第一个到达这颗红色星球的探测器是美国宇航局的“水手4号” The very first spacecraft to reach the Red Planet was Nasa's Mariner 4 probe.

当水手4号掠过火星时， As Mariner 4 swept past Mars,

它的黑白摄像机拍摄了22张火星的特写照片。 its black and white television camera snapped 22 close-up pictures of the planet.

这些图像，火星的第一张影像数据， These images, the first-ever digital television pictures,

存储在磁带上。 were stored on a tape recorder.

然后必须用无线电传回地球。 Then they had to be radioed back to Earth.

但早期水手探测器的成功并不能代表火星任务的真相， But the early successes of the Mariner probes paint a false picture,

因为火星上到处都是失败任务的残骸。 because Mars is littered with the wreckage of failure.

火星探索的历史相当曲折。 The history of Mars exploration is pretty chequered.

我们的成功率实际上比50/50还差。 It's actually worse than 50/50, our success rate there.

它更像是我们向火星投过去的每三个物体中有一个 It's more like one in every three objects that we throw at Mars actually

能到那里成功完成任务。 gets there and completes its mission.

美国宇航局的“水手3号”和“水手8号”在发射后不久就失败 Nasa's Mariner 3 and Mariner 8 probes were both destroyed shortly after launch.

俄国人遭受了最严重的损失， But the Russians suffered the worst losses,

他们在1960年至1971年间的每一次尝试都失败了。 failing with every attempt they made to reach Mars between 1960 and 1971.

然后，在20世纪90年代，又轮到美国人遇到麻烦了。 Then, in the 1990s, it was the Americans' turn to hit trouble again.

两次引人注目的任务出错了， Two high-profile missions went wrong,

第一个是因为搞笑的白痴原因。 the first in an almost comically inept way.

说起来，这是我们很多人犯的错误， Now, it's a mistake many of us have made,

但我们大多数人并不负责太空任务。 but then most of us aren't in charge of missions into space.

美国国家宇航局的科学家们不明白为什么火星轨道器 Scientists at Nasa couldn't work out why the Mars Orbiter,

价值7800万英镑，在太空迷失， worth a small £78 million, got lost in space,

直到有人指出他们的设计单位都是英尺和英寸 until someone pointed out that they'd planned everything in feet and inches

而不是米和厘米。 rather than metres and centimetres.

仅仅三个月后，另一个任务，还有更多坏消息。 Only three months later, another mission, and more bad news.

美国宇航局不得不承认另一个 American space agency Nasa is on the verge of having to admit to another

令人尴尬的失败。 embarrassing failure.

火星极地着陆者将是它丢失的第二个航天器 The Mars Polar lander would be the second spacecraft that it's lost in

仅仅两个月之中。 - just two months.

-三天过去了，仍然没有收到着陆器的信号。 - Three days on, and still no sign of their lost lander.

美国宇航局的工程师们曾认为这只是天线指向的问题 Nasa engineers had thought it was just a case of a misdirected

通信天线的指向。 communications antenna.

后来看来航天器很可能受到严重损坏。 Now it looks likely that the spacecraft could be seriously damaged.

21世纪我们的成功率几乎没有提高。 The 21st century has brought little improvement in our success rate.

2003年，英国小猎犬2号着陆器失事， In 2003, the British Beagle 2 lander was lost,

显然是撞到了火星表面而毁坏的。 apparently destroyed on impact with the Martian surface.

2016年，夏帕雷利登陆器走向了一个更加悲惨的结局， And in 2016, the Schiaparelli lander came to an even more violent end,

它在火星表面摔得到处都是。 its remains now smeared across the Martian landscape.

考虑到这个破碎的，有时，令人尴尬的记录， Given this patchy and, at times, embarrassing track record,

我们真的应该计划把人类送上火星吗？ should we really be planning to send humans to Mars?

去火星旅行， To travel to Mars,

你说的是穿越数亿英里 you're talking about crossing hundreds of millions of miles of

行星际空间， interplanetary space,

以每小时数千公里的速度尖啸着冲进大气层，然后尝试着 screaming into a re-entry at thousands of kilometres an hour, and then trying

在没有直接指令输入的情况下独自降落在行星表面 to land on the surface of a planet on your own with no real direct input

经过数月的旅行之后。 from Earth, after months and months of journeying.

这对无人探测器来说已经够难了。 That's hard enough to do with unmanned vehicles.

所以这将是人类船员面临的一个重大挑战。 So it's going to be a significant challenge for human crews.

从表面上看，我们将人类送入太空的记录令人乐观。 Superficially, our record of sending humans into space gives cause for optimism.

阿波罗是巨大的成就。 Apollo was a triumph.

但自从阿波罗之后，可以说我们已经倒退了。 But since Apollo, it can be argued that we've regressed.

自1972年12月以来， Since December 1972,

当阿波罗17号从金牛座陨石坑返回后， when Apollo 17 blasted off from Taurus-Littrow crater,

没有人再到距离地球表面超过250英里的地方冒险。 no human has ventured more than 250 miles from the surface of the Earth.

英国第一位宇航员海伦·沙曼不同意这点。 Britain's first astronaut, Helen Sharman, disagrees.

她觉得我们在国际空间站积累的经验， She feels our experiences with the International Space Station and

还有航天飞机都是将人类送上火星的必要准备步骤。 the space shuttle have been the perfect preparation for sending humans to Mars.

我们已经从技术上学会了如何制造更可靠的航天器， We've learnt technically how to create more reliable spacecraft,

如何创建更好的冷却系统， how to create better cooling systems,

如何以不同的方式产生能量。 how to generate energy in different ways.

所以，我们学到了很多东西，它将为我们提供更好的帮助 So there's lots that we've learnt, and it will provide us in good stead

为了未来。 for the future.

尽管许多无人火星任务失败了， Despite the failure of many robotic missions to Mars,

我们在人类空间任务方面取得了一些进展。 we have made some progress in human space flight.

但我们无法摆脱的是规模的问题。 But there's no getting away from the scale of the challenge.

第一个大问题就是火星任务出发的时候， The first big problem happens right at the start of the mission.

把人类送上火星需要一些超重型的发射任务。 Sending humans to Mars will require some seriously heavy lifting.

起飞

当我在太空中飞驰之时，我心中一个想法挥之不去

火箭上的每个零件，都来自最便宜的那个投标者

把阿波罗送入太空需要个子最大和推力强大的火箭 Putting Apollo into space required the biggest and most powerful rockets

但与火星需要的相比，它们显得微不足道。 ever built. But they're puny compared to what will be needed for Mars.

当你谈论探索火星的时候，关键是你想带多少东西， When you're talking about exploring Mars, it's all about how much you want to take with you,

你想带什么去那里，你想带谁去。 what you want to pack to go there, who you want to go.

这关乎你想要运送到火星表面的质量。 It's about the mass that you want to deliver to the surface of Mars.

你想带去火星的每一公斤至少需要几十公斤，如果不是几百公斤- And so every kilo you want to take to Mars requires tens - if not hundreds -

的火箭把它运送到低地球轨道。 of kilos of equipment to move it to low Earth orbit.

据估计，即使是适度可行的载人火星任务也需要 It's estimated that even a modest crewed mission to Mars will require

40吨的有效载荷。 a payload of 40 tonnes.

这是将好奇号探测器送至火星所需的40倍。 That's 40 times what was needed to send the Curiosity rover to Mars.

把它送离地面是一项艰巨的任务。 And just getting that off the ground would be a mammoth task.

从重力深井中飞出来， Climbing out of the deep gravity well,

像地球这样的行星周围存在巨大的引力， that huge force of attraction around a planet like Earth,

这是最难的一点。 is the most difficult bit.

它需要爆炸性的能量释放，巨大的能量， It requires an explosive release of energy, massive energy,

相当于小型核武器大小的能量， energy comparable to the size of a small nuclear weapon,

把一艘飞船和团队人员送入近地轨道。 to get a vehicle and her crew into low Earth orbit.

所以在人类的空间任务中，在所有的空间任务中， And so in human space flight, in all of space flight,

前250英里是最难的250英里。 the first 250 miles are the hardest 250 miles.

现在有几种不同的途径。 Several different approaches are being planned.

我们的猎鹰9号起飞了， We have lift-off at the Falcon 9.

神奇的，第一级推进火箭。 Miraculous. That's first-stage acceleration.

SPACEX，南非企业家Elon Musk的创意， SpaceX, brainchild of South African entrepreneur Elon Musk,

是靠轻便的， is banking on small,

可将有效载荷送入轨道的可重复使用火箭 lightweight reusable rockets that can shuttle payload into orbit

然后回来发射更多的任务， and then come back to pick up more,

尽管早期的测试结果好坏参半。 though early test results have been mixed.

还有国家宇航局， And then there's Nasa.

以阿波罗计划土星五号火箭为模板， With the Apollo programme Saturn V rocket as their template,

他们决定走一条直截了当（厚颜无耻）的美国路线， they've decided to take an unashamedly American route

往大了造。 by going large.

美国宇航局的火箭被称为太空发射系统（SLS）， Nasa's rocket is called the Space Launch System or SLS.

一旦完成，它将成为有史以来最强大的火箭。 And when it's complete, it will be the largest and most powerful rocket ever built.

它比我们以前做过的要大得多，高得多。. It's so much larger than what we did here before, so much taller.

组装这么复杂这么大的东西的最好方法是 The best way to assemble something this complex and this big is to

垂直装配。 assemble it vertically.

这是我们用电梯能达到的高度。 This is as high as we can go using the elevator.

剩下的得靠步行。 The rest is on foot.

很难说，在这么大的空间里， It's hard to tell, with this big of a space,

实际的火箭和飞船有多大。 how big the actual vehicle's going to be, the rocket.

实际上，你已经看到了一些线索。 You can actually already see some signs emerging.

你可以看到正在施工的蓝色圆圈。 You can see that blue circle forming.

那是火箭的实际直径。 That is the actual diameter of the rocket.

即使在这个高度，我们也不能装下整个火箭。 And even at this height, we cannot contain the entire rocket.

在密西西比州的斯坦尼斯， In Stennis, Mississippi,

美国国家宇航局测试了火箭发动机，它将向太空发射SLS。 Nasa test the rocket engines that will power the SLS into space.

像这样的引擎只是六个引擎中的一个，它将用于推动SLS进入轨道。 An engine like this will be just one of six which will help propel the SLS into orbit.

所以当测试更大的SLS火箭时， So when the time comes to test the much bigger SLS rocket,

一定是在他们最大的试验台上。 it must be at the largest stand they have.

火星任务也是一样， Like so much in the mission to Mars,

他们将站在国家宇航局之前任务的基础上， they'll be standing on the shoulders of Nasa's previous missions,

从阿波罗号和航天飞机项目借来并重新调整其用途。 borrowing and repurposing the best from Apollo and the shuttle.

-怎么样，伙计？ - How's it going, man?

-一切都很顺利。 It's going good.

-好的。 All right.

B座是50多年前建造的用来测试土星火箭的 B Stand was built over 50 years ago to test the Saturn rockets that

把阿波罗任务送上太空。 carried the Apollo missions to space.

加里·本顿和他的团队将对这个试验台进行改造和升级 Gary Benton and his team will be reshaping and upgrading this stand

以便它能应对下一代火箭。 so that it can cope with the next generation of rockets.

这是我们用来提起土星五号核心级的同一台起重机， This is the same crane that we used to lift those Saturn V core stages,

我们要用同样的起重机 and we're going to use that very same crane

提起SLS核心级并放置 to lift up the SLS core stage and place it

在这个设施里，把它固定好， in this facility, anchor it down really good,

大约200万磅的推力，这是我们 fire off about two million pounds of thrust, and that's going to be

做土星五号以来所进行的最大测试。 the biggest test we've done out here since we did the Saturn V.

有一种明显的兴奋感， There's a palpable sense of excitement here,

因为几十年来第一次 because, for the first time in decades,

他们正在考虑用这些火箭把人送离地球轨道。 they're thinking of using these rockets to send people beyond Earth's orbit.

目前，这是美国国家宇航局用火箭飞向火星的最佳设想图 For now, this is Nasa's best vision of what a rocket bound for Mars

-看起来就是这样。 - would look like.

-倒数10，9，8，7，6，5… - T-minus ten, nine, eight, seven, six, five...

但第一枚完整的SLS火箭仍然是一个遥远的梦想， But the first complete SLS rocket is still a distant dream,

而且愈发遥远。 and it gets worse.

美国国家宇航局估计，他们将为一次火星任务发射七次火箭 Nasa estimates they will need seven SLS launches for a single Mars

让巨大的火星飞船在太空中拼接在一起。 mission so the huge Mars spacecraft can be pieced together in space.

但至少这个问题只是力量堆积的问题， But at least this problem is just a question of brute strength.

把足够的钱砸进去，就能找到解决办法。 Throw enough money at it, and solutions should be found.

但是，下一个分阶段提出了一系列截然不同的挑战。 But the next stage of the journey poses a very different set of challenges.

火星旅程

我想去火星吗？是的。可我不想花9个月才能到那里

然后再等18个月才等到回家的时机

关于火星之旅有一个令人不安的事实， There's an uncomfortable truth about the journey to Mars.

至少3400万英里，比月球远120倍， At a minimum of 34 million miles, 120 times more distant than the moon,

这比人类以往任何一次空间任务都要远两个数量级。 it's two orders of magnitude further than any journey humans have ever made before.

利用现有技术，如果你使用化学推进， With existing technology, if you're using chemical propulsion,

然后单程到火星的旅程是在六到九个月之间， then a journey to Mars is between six and nine months in one direction,

从地球到火星就这么久。 so from Earth to Mars.

然后你必须呆在火星上等待正确的行星排列 And then you have to sit on Mars and wait for the right planetary alignments

回地球的时机，大约在30天左右出现， to be able to get back, and those come up at about 30 days or so,

下一次大约一年半之后。 and then again about a year and a half later.

所以火星任务最短来说一年多就要结束， So the shortest mission that you could hope for for Mars is just over

最长的算起来快要三年。 a year. The longest ones are approaching three years.

三年的任务几乎是我们现有任务的三倍 A three-year mission would be nearly triple the length of anything we've

曾经实施过的，在太空中那么久会带来一些严重的风险。 done before, and spending that long in space poses some serious risks.

第一个问题是辐射。 The first problem is radiation.

在火星任务中你会受到多少辐射 Just how much radiation you would be exposed to on a mission to Mars was

由最近的好奇号任务精确量化， quantified by the recent Curiosity mission,

他们发现辐射强度是地球表面的几百倍。 and they found it to be several hundred times more intense than on Earth.

这是个问题。 And that's a problem.

地球上生命繁盛以及我们发展进化的一个重要因素 One important factor of life on Earth and how we were able to evolve

是我们受到了对抗辐射的保护 is that we're protected from the radiation

包括宇宙射线和太阳辐射 of galactic cosmic rays and from the radiation

地球磁场对辐射有屏蔽作用， of the sun by the magnetic field of the Earth,

它是由地球的铁核造成的。 which is caused by the iron core of the Earth.

磁场在我们的地球周围形成了一个保护罩，叫做 That magnetic field creates a protective shield around our planet called

地球磁层，使辐射偏转。 the magnetosphere, which deflects radiation.

危险的太阳粒子不能通过， The more dangerous solar particles don't get through.

造成了壮观的极光现象。 Those that do create the spectacular light show of the aurora.

但在太空中，一切都不一样。 But out in space, everything is different.

这里，翻滚的太阳表面偶尔会发生一次巨大的爆炸， Out here, the bubbling surface of the sun occasionally builds to a huge explosion.

这些太阳耀斑释放出大量的辐射和高能质子， These solar flares throw out massive bursts of radiation and high-energy

可能破坏你DNA的质子， protons which might damage your DNA,

以后会诱发突变和癌症。 causing mutations and cancer later in life.

屏蔽辐射相当关键，如果我们要成功地 Protecting against radiation will be crucial if we are to successfully

送人去火星。 send people to Mars.

我们需要的是保护宇航员的材料，在发生太阳风暴 What we need is a material that can shield astronauts in the event of a

的时候，但不会增加航天器的额外重量。 solar storm, but doesn't add extra weight to the spacecraft.

美国宇航局的答案是使用他们已经携带的物资， Nasa's answer is to use something they will already be carrying,

一种以吸收太阳辐射的能力而闻名的物质… a material known for its ability to absorb solar radiation...

水。 Water.

所以我们想要一件衣服，把它装满水， So we're looking at taking a garment and filling it with water,

你在这里看到的是第一款概念服，宇航员 which you see a first concept of here, of this astronaut

在其可穿戴的衣服中装入水墙。 with a water wall built into its wearable garment.

所以这是一个你可以填充的宇航服。 So this is something that you'd fill for an event.

所以他得到了明显的保护， So he gets protection in maybe a different form,

但它带来的重量影响要小得多。 but with a lot less mass penalty to it.

不幸的是，对于火星宇航员来说， Unfortunately for Martian astronauts,

辐射只是问题的开始。 radiation will only be the start of the problems.

更致命的威胁在发射几分钟后就会发生。 An even more pernicious threat begins only minutes after launch.

现在让我们向后试试。 Now let's try backwards.

你的身体开始体验失重 Your body starts to experience weightlessness

从你进入低地球轨道开始， as soon as you get into low Earth orbit,

从你进入太空的那一刻起，你的身体就开始改变。 and that starts modifying your body from the moment you deploy in space.

对你的骨骼和肌肉有影响， And that has effects on your bones and your muscles,

因为这些很快就会被削弱。 because those go to waste very quickly.

现在的办法是锻炼——而且大量。 The answer, for now, is exercise - and lots of it.

Libby Jackson在担任飞行指挥时所了解的事情 Something that Libby Jackson knows only too well from her days as flight director

在国际空间站哥伦布科学舱工作时， of the International Space Station's Columbus science module.

国际空间站上的团队人员必须 The crew on board the International Space Station have to exercise for

每天运动大约两小时。 about two hours every day.

大约一个小时的有氧运动 That's about an hour of cardio

加一小时的力量训练。 and an hour of what we would call weights.

他们没有举起重量，你不能在失重的情况下这么做 They're not lifting weights, you can't do that in a weightless

但他们有一个液压缸，给他们阻力。 environment, but they have a hydraulic ram that gives them resistance.

你需要保持身体健康 You need to keep your body in a condition

当你到达火星时，可以承受你的工作。 that allows you to function when you get to Mars.

但是凯文喜欢用另一种方法来解决零重力问题… But Kevin favours a different approach to the problem of zero gravity...

…一个需要重大技术飞跃的项目。 ..one that will require a major technological leap.

我们带着我们的光，我们的热，我们的能量，我们的水、食物， We take our light, our heat, our power, our water, our food,

我们甚至带着我们的大气。 we take even our atmosphere with us.

那我们为什么不带着重力呢？ So why don't we take gravity?

现在看来，这并不像听起来那么科幻。 Now it turns out that that's not as sci-fi as it sounds.

你可以通过建造大型旋转飞船来实现。 You can do that by building a large rotating vehicle.

我说的是一艘伦敦眼大小的飞船 I'm talking about a vehicle about the size of the London Eye that would spin

大约一分钟转四次。 about four times a minute.

这足以提供相当的重力， That would be enough to provide this level of gravity,

1G的地球重力载荷。 a 1G Earth gravitational load.

这将解决我们的许多问题。 And that would wash away an awful lot of our problems.

这种人工重力装置可能有它的好处， An artificial gravity device of this kind may have its benefits,

但这会给已经很困难的任务增加巨大的成本和重量。 but it would add huge cost and weight to an already difficult mission.

第三个巨大的挑战是与世界隔绝的感觉， The third huge challenge is that sense of isolation from the world,

难以回家。 not being able to get back easily.

与可以通过技术来处理的物理威胁不同， Unlike the physical threats that have the potential to be managed with technology,

去火星旅行的心理风险 the psychological dangers of a journey to Mars are much harder

难以量化。 to quantify.

宇航员将不得不面对两个挑战： Astronauts will have to deal with the twin challenges of isolation from

远离他们在地球上的亲人 their loved ones on Earth

与他们的同伴关在一起。 and close confinement with their fellow crewmates.

我最喜欢的一句话是瓦莱里·赖敏的话， One of my favourite quotes is from Valery Ryumin,

他是一个俄国人，执行了太空站任务 who was a Russian who flew their Salyut space station missions

我想是在1970年代，1976年。 in the 1970s, I think in 1976.

他说谋杀的所有必要条件都达到了 He said all the conditions necessary for murder were met

如果你把两个人锁在一间小屋里三个月。 if you lock two people in a cabin for three months.

这些任务长达30个月，这是一个非常考验的时间。 These missions are going to be up to 30 months, a very testing time.

发动机启动，五，四，三，二，一。 Engines on. Five, four, three, two, one.

所有发动机运转 All engines running.

升空！我们升空了。 Liftoff! We have liftoff.

挑选一名船员进行这么长的任务是很棘手的。 Picking a crew for a journey of this length will be tricky.

在阿波罗11号的时代，宇航员的招募很简单。 Back in the days of Apollo 11, astronaut recruitment was straightforward.

谁有合适的才华很明显。 It was clear who had the right stuff.

尼尔·阿姆斯特朗 Neil Armstrong,

巴兹·奥尔德林和迈克尔·柯林斯是超音速飞行的精英。 Buzz Aldrin and Michael Collins were the cream of US supersonic flight.

他们来自战斗机和试飞员的精英群体， They were drawn from the elite world of fighter and test pilots,

伴随这些职业的，是最佳的手眼协调和身体胆量。 and with that came supreme hand-eye coordination and physical daring.

但这些可能不是你去火星所需要的技能。 But these may not be the same skills you'd need to go to Mars.

我注意到许多宇航员都有传统的生活爱好。 I noticed that a lot of the astronauts were of the old school.

“我打猎，钓鱼，爬山。” "I hunt, I fish, I climb mountains."

你知道，很多户外运动。 You know, lots of outdoor stuff.

但想想去火星的任务， But think about a mission to Mars.

是户外运动，还是关禁闭？ Is it outdoor stuff, or is it confinement?

然后我看到有人说“我收集邮票， And then I see somebody that says "I have a stamp collection,

“我经常读书，我喜欢看电影。” "I do a lot of reading, I enjoy watching movies,"

我在想，“这可能有利于封闭环境。” and I'm thinking, "That might be good for confinement."

大卫·丁格斯博士对如何挑选团队很感兴趣 Dr David Dinges is interested in how you select a crew

以及如何保障他们在太空中的心理健康。 and safeguard their psychological welfare in space.

关键是要了解谁会产生问题 The key issue is understanding who's going to develop a problem

以及何时变得严重。全体船员都产生问题吗？ and when it will develop. Will all the crew develop it?

我们如何发现？ How do we detect it?

我们该如何预防呢？ How do we prevent it to begin with?

迄今为止，唯一的答案来自俄罗斯的研究， To date, the only answers come from a Russian study,

在隔离状态下约520天的地面任务 an earthbound simulation of the approximately 520 days in isolation

这是一次往返红色星球的全程模拟。 it would take for a return trip to the Red Planet.

随着俄罗斯研究的进展，丁格斯给自己设置了一道难题。 As the Russian study was gearing up, Dr Dinges set himself a challenge.

他能运用自己的专业知识来预测 Could he use his expert knowledge to anticipate

谁最适应封闭环境吗？ who would fare best in confinement?

在火星520任务中，我仔细观察了团队成员。 In the Mars 520 mission, I watched the crew intensively.

我想在媒体关注的焦点中看到他们的反应 I wanted to see them during the maelstrom of media attention

在他们进舱之前，以及他们是如何互动的 before they went into the chamber and how they interacted

在那种环境和身体姿势下- in that environment and body posture -

他们在看什么，说什么。 where they were looking, what they said.

我写了很多东西，我做了预测， I wrote down a variety of things. I made predictions,

这是真的-我把它封在一个信封里然后把它放在 and this is true - I sealed it up in an envelope and put it

抽屉里等任务结束。 in the drawer and waited till the mission was over.

在这段视频中， In this footage,

由欧洲航天局发布，宇航员们看起来很好。 released by the European Space Agency, the astronauts look well.

但到最后，深深的麻烦正冒出来。 But by the end, deep troubles were brewing.

最重要的是，在六个人中， The bottom line is that, out of six people who went,

只有两个人没有明显的行为问题 only two didn't have significant behavioural problems

这种或那种。 of one kind or another.

他们中的一些人失眠了。 A couple of them experienced insomnia.

一个人经历了抑郁。 One experienced some depression.

嗯，另一个比较孤立。 Um, another was more socially isolated.

但我预测那两个能顺利完成的队员，真的表现很好。 But the two I predicted would make it just fine, made it just fine.

似乎把宇航员送上火星的所有问题 It seems that all the problems of putting astronauts on Mars

回到一件事上——任务中人类这样纤弱易损的载荷。 return to one thing - the mission's delicate payload of human beings.

即使他们在旅途的危险中幸存下来， And even if they survive the perils of the journey,

旅行中最危险的15分钟仍然在前方。 the most dangerous 15 minutes of the trip would still be ahead.

登陆

我想死在火星上，但不是摔死。

在经历了九个月的心理和身体不适之后， After nine months of psychological and physical discomfort,

火星之旅的最后几分钟 the final few minutes of the journey to Mars

提出一些最大的挑战。 present some of the biggest challenges.

首先是通信。 The first is communication.

地球和火星都在围绕太阳的轨道上， Earth and Mars are both in orbit around the sun,

所以当我们在最近的时候，他们之间的时间延迟 and so the time delay between them when we're at our closest, when

我们在轨道上的同一点位置时，大约只有四分钟。 we're at the same points in our orbit, is only about four minutes.

但是如果我们在太阳的一边而火星在另一边 But if we're on one side of the sun and Mars is on the other side

太阳两侧，单程最多可以有24分钟， of the sun, that can be as much as 24 minutes one-way,

这意味着如果任务控制中心正在发送信息 which means that if mission control are sending a message

给宇航员，需要48分钟才能得到回答。 to the astronauts, it can take 48 minutes for the answer to come back.

这完全改变了宇航员的支持方式 And that just completely changes how your astronauts are supported

在地面上的你的后援团队。 by your teams on the ground.

当我们去月球的时候， When we went to the moon,

通信延迟了一两秒钟。 there was a delay of about a second or two in the communication.

船员们不得不操作发动机， The crew had to fire their engines

进入月球背后的月球轨道， to go into lunar orbit behind the moon,

任务控制所能做的就是说，“你的电脑已经开启。 and all mission control can do is say, "Your computers are loaded.

祝你好运。我们在另一边见。” "Good luck. We'll see you on the other side."

火星将会发生同样的事，不过是百倍难度。 And what will happen with Mars will be like that, but a hundredfold.

通信的挑战可能会使登陆火星变得棘手。 The challenges of communication might make landing on Mars tricky.

但对凯文来说，还有一个更大的问题， But for Kevin, there's a far bigger problem,

就是这颗红色星球的稀薄大气层。 and that's the Red Planet's thin atmosphere.

火星的大气层是最糟糕的 The Martian atmosphere is the worst of all worlds when it comes to

离开太空要减速的时候。 stopping in space exploration.

它太过稠密，不能让你安全通过， It's too thick to let you through safely,

但是它又太稀薄，不能给你足够的减速作用 but it's too thin to provide you with enough deceleration

使你达到一个合适的速度。 to get you down to a useful speed.

这不像登月，这不像是重返地球。 It's not like landing on the moon. It's not like re-entry on Earth.

它需要许多新颖的解决方案。 It requires a lot of novel solutions.

在历史中我们也看到过 And we've seen some of that in our history

对那颗行星的无人探索。 of robotic exploration of that planet.

火星探险史上最大胆的登陆是 The most audacious landing in the history of Martian exploration came

2012年，好奇号探测器在盖尔火山口着陆。 in 2012, when the Curiosity rover touched down in Gale Crater.

由美国国家宇航局亚当·斯特尔茨纳博士设计的宇宙芭蕾 It was a cosmic ballet choreographed by Nasa engineer Dr Adam Steltzner.

好奇号落地，一吨- Landing Curiosity, a tonne -

迄今为止我们在火星上着陆的最大的物体。 the biggest thing we've landed on Mars to date.

这是一个挑战，但远不及人类登陆的挑战。 A challenge, but not nearly as much of a challenge as landing humans.

人类是敏感的，他们很脆弱。 Humans are sensitive, they're delicate.

他们不喜欢很多G的加速度。 They don't like a lot of Gs.

他们必须随身携带水。 They like to carry water with them.

他们很重。 They're heavy.

所以我们认为人类登陆可能需要 So we think that landing humans might be something

大约40吨，或者更重。 like 40 metric tonnes, or maybe more.

对载人飞船来说， Once again, for the spacecraft carrying humans,

规模越大，挑战就越大。 it's the bigger size that raises challenges.

有一个有趣的物理原理会发生 There's this interesting pit of physics that occurs

当你扩大规模的时候。 as you scale up things.

想象一下把一滴水放大。 Imagine scaling up a drop of water.

在变大变小的过程中， As it gets small or big,

它的重量随着它的变大而变大… its weight goes up with the size of it...

..立方，增大三次方。 ..cubed, raised to the third power.

但是它的空气阻力随着面积的增大而增大， But its aerodynamic drag gets larger based on its area,

它的直径的平方。 which is its diameter squared.

意思是体型相似的东西越大， What that means is the bigger the self-similar thing gets,

它掉下来越快。 the more easily it falls.

同样的事情也发生在航天器上。 The same thing happens with spacecraft.

所以如果你考虑好奇号， So if you think about Curiosity,

她进入的速度非常非常快，放慢了速度， she came in going very, very fast, slowing down,

减速并最终落在表面。 slowing down and eventually making contact with the surface.

较小的好奇号意味着它成功地放慢了速度 The smaller size of Curiosity meant that it was successfully slowed

当它下降时利用空气的阻力。 by aerodynamic drag as it fell.

但是要扩大人类登陆车的规模 But scaling up the size for a human lander

从根本上改变了着陆的物理特性。 changes the physics of landing radically.

我有一个体型相似的物体， I've got this self-similar shape.

不是把好奇号降落在表面上， I'm not going to not put Curiosity on the surface,

而是放两个好奇号，好的，三，四，五 but I'm going to put TWO Curiosities, OK, three, four, five.

有点挑战性， Getting a little challenging.

40个。突然间，同样的形状飞不了。 40. Now all of a sudden, I can't fly that shape.

它的形状是和以前一样。 It's the same shape it was before.

它的密度与好奇号航天器相同， It's packed at the same densities of spacecraft,

但现在它飞出的轨道 but now it ends up flying a trajectory

与火星表面相交时以20马赫的速度运动。 that intersects the surface of Mars when it's moving Mach 20.

不好。 Not good.

也许为了把大东西降落到火星表面， Perhaps to get really big things to the surface of Mars,

我们需要做的是… what we need to do is...

我们需要使形状像这样，看起来像常规火箭， We need to make our shape like this, which regular rockets look like,

但当我们飞进来的时候，我们不会把尖头插进去 but when we come flying in, we don't put the pointy end in

或者是后段——而是从侧面进入。 or the back end in - we come in sideways.

从侧面进入的话， By coming in sideways,

航天器上的阻力显著增加， the drag on the spacecraft is increased significantly,

把火箭从高超音速减速到超音速。 slowing the rocket from hypersonic to supersonic.

为了进一步降低速度， To slow it down further,

你需要别的东西来对抗火星的引力。 you need something else to push against the gravity of Mars.

它被称为超音速反推。 It's called supersonic retro-propulsion.

想象一下，以60英里/小时骑摩托车时，你把嘴张开 Imagine motorbiking with your mouth open at 60mph.

哇！它让你的嘴充满空气 Waah! It fills your mouth with air

事实上有时很难呼气。 and it's actually sometimes hard to breathe out against it.

嗯，这是超音速反推的挑战。 Well, that is the challenge of supersonic retro-propulsion.

你在气流中可以启动火箭喷射， You can light a rocket off into the flow,

但它是超音速的气流。 but it's going to be supersonic flow.

嗯，美国宇航局正在研究这个问题。 Well, Nasa's working on that.

很可能用那些火箭从超音速状态 And it's likely to take those rockets from a supersonic condition

一直降落到表面。 all the way down to the surface.

如果Stelzner博士的想法成功了 If Dr Stelzner's idea is developed,

这将为宇航员在火星表面登陆铺平道路 it would pave the way for astronauts to land on the Martian surface

第一次登陆。 for the first time.

但即使他们安全到达， But even if they arrive safely,

他们将面临一个即时且潜在的致命挑战。 they will face an immediate and potentially deadly challenge.

对于我们这些想象它是什么的人来说，最困难的事情之一 One of the most difficult things for those of us who imagine what it's

就是想象一个人类成员 going to be like for a human crew

到达火星时处于怎样的状态 arriving at Mars is what shape they're going to be in

他们将如何照顾自己， and how they're going to look after themselves,

因为他们六个月或九个月后就要到达 because they're going to arrive after six, maybe nine months

在飞行过程中，他们的身体会产生彻底的效应 of flight with all the deconditioning of their bodies

我们知道会发生的反应。 that we know is going to have happened.

他们不会面对庞大的医疗专业团队 And they're not going to be met by a huge army of medical professionals

科学家们可以把他们送进 and scientists who can then scoop them into

一流的医院。 a state-of-the-art hospital.

海伦·沙曼在执行任务期间只在太空呆了八天， Helen Sharman spent only eight days in space during her mission

1991年在和平号空间站。 to the Mir space station in 1991.

但她完全依赖专业团队的服务 But she was completely reliant on the welcoming committee waiting

迎接她着陆。 for her on landing.

我们一着陆，飞船就被营救人员扶起来了。 Once we landed, the spacecraft was uprighted by the rescue crew.

救援人员把我们从飞船上救了出来， The rescue crew pulled us out of the spacecraft,

把我们从一个小斜坡滑到座位上， glided us down a little sort of ramp into seats,

然后医生来监测我们的血压和其他身体状况 and then doctors came to monitor our blood pressure and other bodily

直到他们确定了我们身体健康。 functions before they decided that we were fit and healthy.

宇航员登陆火星将不会有这样的奢侈， There will be no such luxuries for astronauts landing on Mars.

他们只能靠自己，必须自己照顾自己。 They're going to be on their own and have to fend for themselves.

所以这取决于计划任务的团队， And so it is down to the crews who plan the missions,

临床医生和准备任务的医生 down to the clinicians and the physicians who prepare them

为他们保证尽可能好的医疗条件。 to deliver them in as good medical condition as they possibly can.

如果我们能解决安全登陆火星的挑战， If we can solve the challenges of landing safely on Mars,

它将为人类创造条件 it would set the stage for humans

第一次在另一颗行星的表面行走。 to walk on the surface of another planet for the first time.

但是我们能实现无人着陆器不能实现的目标吗？ But what could WE achieve that robotic landers couldn't?

我们如何应对表面工作的挑战？ And how would we deal with the challenges of working on the surface

另一颗星球？ of another planet?

火星表面

如果一条狗在距离海盗号一米远的地方拉屎

海盗号根本就不会发现

风声 WIND WHISTLES

在过去的五十年里， Over the last five decades,

机器人是我们探索火星表面的唯一途径。 robots have been our only way of exploring the surface of Mars.

他们是我们的宇宙使者， They've been our cosmic emissaries,

收集数据和图像供我们在地球上研究。 gathering data and imagery for us to digest back on Earth.

但是对于凯文来说，他们的局限性太大了。 But for Kevin, their limitations are too great.

对我来说，火星就代表生命， For me, Mars is all about life,

当你看到我们探索的历史 and when you look at the history of our exploration

研究地球上早期的生命形式， of early forms of life on this planet,

是由一群地质学家在岩石上敲击而发现 it was found in rocks by teams of geologists bashing on rocks and

检查它们并提出想法 examining them and coming up with thoughts

指明下一个探索地点。 about where to explore next.

它不是也不可能通过机器人找到 It was not and it could not have been found by parachuting something

通过投放像是R2-D2的机器人进入那个区域。 that looked like R2-D2 into that territory.

这就是利弊的权衡， That's the scale of the challenge,

这就是为什么你需要人类在火星上。 and that's why you need humans in situ on Mars.

但是如果我们到了那里，在火星上工作不会那么容易。 But if we get there, working on Mars will be no cakewalk.

与地球不同，火星没有保护磁场。 Unlike Earth, Mars has no protective magnetic field.

所以辐射仍然是宇航员最大的敌人。 So radiation continues to be an astronaut's biggest enemy.

温度的剧烈变化， Wild variations in temperature,

从冬季零下150度到夏季20度， from minus 150 degrees in winter to 20 degrees in summer,

是另一个潜在的杀手。 are another potential killer.

同时还有另一个风险… And with this comes another risk...

强大的沙尘暴可以覆盖整个星球。 Powerful dust storms which can shroud the entire planet.

所以宇航员在火星表面上要想生活和工作都很舒适， So for astronauts to live and work comfortably on the Martian surface,

他们需要一种新的保护方式。 they're going to need a new form of protection.

研究下一代宇航服的科学家正在 And scientists working on the next generation of spacesuits are taking

从一个恶名远扬的案例中获得灵感 inspiration from a notorious incident

在阿波罗16号任务期间， during the Apollo 16 mission.

在月球表面行走时， Whilst walking on the lunar surface,

宇航员查理·杜克掉了锤子， astronaut Charlie Duke dropped his hammer.

但是他的宇航服的限制性意味着 But the restrictive nature of his spacesuit meant

他拿不起来， he couldn't pick it up.

他很难取回锤子。 He has real trouble retrieving the hammer.

所以，他不得不摔倒在锤子上。 So he just resorts basically to falling on it.

你可以看到我们进步了很多。 You can see we've progressed quite a ways.

所以现在我们的团队人员，现在我们的项目可以做很多 So our crew members now, and our subjects now can now do a lot

可以做那些实用的、现实的任务 of those functional, realistic tasks that you need to do

以一种更正常的方式，不会让宇航服工程师感到害怕 in a much more normal fashion that didn't scare spacesuit engineers

像查理在阿波罗任务做的那样。 like Charlie did on Apollo.

值得注意的是，自阿波罗时代以来，宇航服几乎没有什么变化 Remarkably, spacesuits have changed little since the Apollo days.

而那些在空间站上穿的也同样笨重。 And those worn on the Space Station are just as bulky.

因此，科学家们正在寻求减重和增加灵活性 So scientists are looking to slim down and add flexibility

采用各种办法。 in any way they can.

这样的设计让它有伸缩关节， This suit was built so it can allow a flexing extension joint,

腰部轴承，可以让他活动自如， a waist bearing, and allows him a pretty wide range of motion,

非常自然。 very natural.

当你走路的时候会经常移动你的腰部，但你没有意识到 And you move your waist a lot when you walk and you don't realise that,

所以这是一个重要的关节。 so that's an important joint to have.

然后我们可以看他蹲下 And then we can watch him squat.

触地。 Touch the ground.

像这样的小改动 Seemingly small developments like this

让我们更接近将人类送上火星的前景。 take us closer to the prospect of sending humans to Mars.

你可以看到关节动作，当他做这些实用的工作。 You can see the joints work as he's doing these functional tasks.

如果我们能为火星宇航员创造合适的工作条件， If we can get working conditions for Martian astronauts right,

科学的回报将是很大的。 the scientific rewards would be huge.

今天，火星科学只能由那些机器人操劳 Today, Martian science can only be conducted remotely by vehicles that

慢慢地在地面上转来转去，收集数据和图像 slowly trundle around the surface, gathering data and imagery.

对好奇号任务项目组的地质学家Sanjeev Gupta教授来说， For Curiosity mission planner and geologist Professor Sanjeev Gupta,

这与人类科学家所做的完全不能匹配 it's just no match for what a human scientist could do.

作为一名从事好奇号任务的科学家， As a scientist working on the Curiosity mission,

我们面临的最大挑战是如何选择去哪儿 the biggest challenge we have is how to pick where to go in the time

在我们工作的时间之内。 period we have to work.

机器人效率不高，而且它们运动能力有局限。 Robots are simply not very efficient and they can't get everywhere.

当我们控制好奇号时，让它执行任务 When we command Curiosity, the tasks it conducts

也许需要几天， in maybe a couple of days,

如果我在那里的话，我可能几分钟内就自己去了。 I could probably do in a few minutes by myself if I was there.

节省时间的因素至关重要。 That time-saving element is crucial.

用好奇号，我们仅仅是在科学的表面掠过， With Curiosity now, we skim at the surface of the science we can do.

我们做了一点点， We can do a bit of it,

但是人类可以做得更好更快。 but a human could just do it so much better and so much faster.

但对凯文来说，这不是机器和人类之间的选择- But for Kevin, it's not a choice between machines and humans -

这是关于人机协同一起工作。 it's about both working together.

探路者火星车花了很多年时间 The Pathfinder rovers took many years

只跑了几公里。 to cover just a few kilometres.

他们在三四年的探索中所走的距离 The distance they covered in three or four years of exploration was the

差不多是一个下午的路程 same as that distance covered in a single afternoon

驾驶阿波罗15号月球车。 by the Apollo 15 lunar rover.

所以你可以看到你能达到多快的速度 So you can see there how much more rapidly you can take on

有人类探险家的时候 an environment with human explorers

与机器合作，而不是人或机器人单独工作。 partnering with machinery than you can with robots on their own.

海伦·沙曼可以专注于别的事情， Helen Sharman prefers to concentrate on something else,

这就给了像她这样的宇航员思考和行动的能力 and that's giving astronauts like her the ability to think and act

为自己计划。 for themselves.

机器人完全依赖于所制定的方案 Robots are totally reliant on the plans that were made

发射之前的方案。 leading up to the launch.

所以，机器人会按照你制定的计划行动 So pretty much, the robot will do what you planned it to do

在数年前发送之前就定下了，而人类可以实施不同的试验。 years before it got sent, whereas humans can do new things.

人类也可以环顾四周。 Humans can also take a look around.

而且，“实际上，那边有一片黑土 And, "Actually, there's a bit of black earth over there

那边的一块白色岩石。 "or a bit of white rock over there.

“尽管我们只打算从这个地区采集样本， "And although we'd only intended getting samples from this area,

“为了得到好的代表性样品， "to get a good representative sample,

“我们还需要一点黑的白的，非常感谢。” "we need to take a bit of black and white as well, thank you very much."

所以人类可以做出这些决定。 So humans can make those decisions.

使人类从事有意义的科研的好处 The prize of putting humans in a position to do meaningful science

在火星表面将是巨大的。 on the surface of Mars would be huge.

我们对近邻的理解将会改变 Our understanding of our nearest neighbour would be transformed

即使在表面上只呆几个小时。 even with only a few short hours on its surface.

还有一个特别的问题 And there's one question in particular

我们极其渴望答案， that we are desperate to answer,

和其他任何疑问相比都更烧脑的问题。 one that has consumed our thoughts more than any other.

火星生命？

在火星上发现点什么东西的几率是百万分之一，

但早晚还是会来的。

-先生们 - Gentlemen.

-宇航员走出太空舱 - The idea of astronauts stepping out of their capsule

受到小绿人的欢迎可能是 and being greeted by little green men may be a hangover

20世纪50年代的二流电影… from 1950s B-movies...

你在这里吗？ Are you here?

…但是火星上是否有生命的问题正在慢慢地指向 ..but the question of whether there is or WAS life on Mars is creeping

有意义的答案。 towards a meaningful answer.

这是一颗享受快乐与和平的星球。 This is a location for great joy and peace on the planet.

道理是这样的，如果生命在那儿， Here's the thing. If it IS there,

这意味着当你仰望夜空时， it means that when you look up at the night sky,

这是一个充满生命的宇宙，那是一个丛林。 it is a universe teeming with life, it's a jungle up there.

如果你到了火星，你不仅发现那里没有生命 If you go to Mars and you find not only is there not any life there

现在，过去也没有，它是一颗贫瘠的星球， now, but there never has been and it's a sterile planet,

那当你望着夜空时，那是一片荒漠。 then when you look at the night sky, it's a desert.

许多科学家认为几率高于50:50， Many scientists put the odds at better than 50-50,

宇航员登陆红色星球的表面 and landing astronauts on the surface of the Red Planet

最终找到具体的证据，有还是没有生命 should finally provide concrete evidence one way or another.

我不知道答案是什么 I don't know what the answer

关于“火星上有生命吗？”所以我们得去看看。 to the question "is there life on Mars?" is. That's why we have to go.

作为一名科学家，我认为这将是非常令人惊讶的 As a scientist, I think it would be highly surprising

生命只在地球上出现。 that life only arose on Earth.

我觉得这是一个非常不可思议的概念。 I find that quite an incredible concept.

火星上生命存在的关键壁垒 The biggest barrier to the existence of life on Mars

是水的存在。 is the presence of water.

在地球上，所有的生命都是以水为基础的。 On Earth, all life is based on water.

它是每个细胞的主要成分， It's the main constituent of every cell,

人们认为水是生命的基本要素 and it's thought that water is an essential ingredient for life

在宇宙的任何地方。 anywhere in the universe.

近一个世纪以来人们都知道有冰盖 It's been known for almost a century that there are icecaps

在火星两极。 at the Martian poles.

但是温度为零下150度， But with temperatures of minus 150 degrees,

这些地方不是寻找生命的好地方。 these aren't good places to search for life.

你需要的是液态水。 What you need is liquid water.

在火星上的第一个迹象出现在20世纪70年代中期。 And the first hint of that on Mars came in the mid-1970s.

这些照片是由海盗号探测器在1976年拍摄的 These photographs taken by the Viking space probe in 1976

看起来像干涸的河谷。 showed what looked like dried-up river valleys.

你可以在这里看到 You can see one here.

你可以看到这里有一个河谷。 You can see there's a valley through here.

你可以看到它的支流。 You can see it branches.

有分支。 There are tributaries.

这里有一个支流带着分支。 Here's one branch going off here with tributaries.

所以这看起来非常像地球的河流系统。 So this looks very much like a terrestrial river system.

如果这些是干涸的河床， If these WERE dried-up riverbeds,

这意味着火星一定曾经拥有过完美的生存条件。 it meant that Mars must once have had the perfect conditions for life.

火星有河流，它必然曾经有溪流，雨水， For Mars to have rivers, it must once have had streams, rain,

云和大气。 clouds and an atmosphere.

但20年来，他们不能确定。 But for 20 years, they couldn't be sure.

答案出现在1998年， The answers would come in 1998,

随着火星全球勘测者的发射 with the launch of the Mars Global Surveyor.

河谷的各个部分被详细地揭示出来。 Sections of the valleys were revealed in fantastic detail.

然后，在他们搜索了数千张图片之后， Then, after they'd searched through thousands of images,

他们找到了这个。 they found this.

一个2公里宽的弯曲河谷，在峡谷的一个拐弯处， A winding valley 2km wide and, at a bend in the canyon,

一条很小的河道——古老河流的清晰痕迹。 a tiny channel - the unmistakable trace of an ancient river.

2015年，更引人注目的事情得到了证实。 In 2015 came confirmation of something even more remarkable.

火星勘测轨道飞行器发回的图像显示 Images sent back by the Mars Reconnaissance Orbiter showed

黑色的条纹，跟随着地表的轮廓变化 dark streaks that seemed to follow the contours of the landscape.

这些水分和盐分的条纹 These streaks of moisture and salt

无可争辩地证明了液态水 were incontrovertible proof that liquid water

仍然在火星表面流动。 still flows on the surface of Mars.

跟着水走，也许当它在地下流动时， Follow that water, perhaps as it flows underground,

也许我们会找到生命。 and maybe we'll find life.

如果生命在火星上，它很可能在地下深处， If life is on Mars, it's most likely deep within the planet,

这意味着必须挖下去， and that means having to dig down,

往下钻很长的距离。很多米，至少是这么深。 tunnel down very considerable distances. Many metres, if not more.

这需要的工作 And that requires an effort

机器人平台本身并不能做到。 that isn't really doable by robotic platforms on their own.

你需要人类在场 You need human infrastructures.

但是把人这样的生命送到火星去寻找外星生命 But sending human life to Mars to hunt for alien life

引发了另一个问题。 presents another problem.

实际上，这有点自相矛盾。 It's a bit of a paradox, actually.

如果你想发现火星上的生命 If you want to discover life on Mars

或者回答“火星上有生命吗？” or answer the question "is there life on Mars?"

把生命送到火星去 sending life to Mars to try and discover that

可能会给火星带来风险。 might put Mars at risk.

行星保护问题- The question of planetary protection -

保护火星和地球免受交叉污染- protecting both Mars and Earth from cross-contamination -

是21世纪任务设计的核心部分， is a central part of 21st century mission planning,

如此重要，它甚至被写在法律中。 so much so, it's even enshrined in law.

因为火星可能还有生命， Because Mars could still have life,

联合国有非常严格的规则来保护这个星球。 there are very strict UN rules on going and protecting the planet.

你需要确保不会干扰火星上的任何生命 You need to make sure that you don't disturb any life on Mars

或者引进任何东西。 or introduce anything to it.

你要确保如果你要带什么回来 You need to make sure that if you were to bring anything back

到地球，我们不能让地球上的生命处于危险之中。 to Earth, we don't put life on Earth at risk.

如果我们不能保证保护火星，那么也许我们不应该去。 If we cannot promise to protect Mars, then maybe we shouldn't go.

但凯文不同意。 But Kevin disagrees.

他认为行星保护是我们已经解决的问题 He thinks planetary protection is something we've already solved

我们在更近的地方有经验。 with our experience closer to home.

我们不得不思考这个问题，当我们在地球钻探 We have had to think about that here on Earth, when we drilled recently

考察南极洲，有人努力在冰上钻了许多米 in Antarctica. There were efforts to drill many, many metres through ice

与周围世界隔绝的古老湖泊 to ancient lakes that had been sealed off from the rest

隔绝超过一百万年 of the world for over a million years.

那些保护问题， And those protection issues,

保护一个系统不受另一个系统的影响，必须提出来。 protecting one system from another, had to be broached then.

所以我们在这个问题上并不是没有成熟的想法 So it's not like we don't have some quite mature thinking in this.

这不是一个无法克服的问题。 And this isn't an insurmountable problem.

假设我们能解决污染问题 Assuming we can solve the contamination issue

做有意义的科研， and do meaningful science,

下一个将要出现的问题更具挑战性。 the next question that will arise is even more challenging

比到达火星还重要。 than the journey to Mars.

回家

火星一号也许该认识到

这场冒险的不现实性了。

当阿波罗宇航员返回地球时， When the Apollo astronauts returned to Earth,

受到了英雄般的欢迎。 it was to a heroes' welcome.

对于前往火星的宇航员来说， But for the astronauts going to Mars,

他们回家的不确定性更大， there's rather more uncertainty about their homecoming,

那是因为从火星回来同样具有挑战性 and that's because coming back from Mars will be just as challenging

就像去那里一样。 as getting there.

美国国家宇航局和SpaceX正在投资重大研究 Nasa and SpaceX are investing significant research

关于这个问题。 into the problem.

尤其是如何携带足够的燃料用于返程， In particular, how to carry enough fuel for a return journey,

或者可以从火星的深处开采。 or even to mine it from deep under the Martian surface.

但荷兰火星一号计划在2032年进行的项目 But the Dutch Mars One project scheduled for 2032

对于这个难题有一个简单明了的解决办法。 has a starkly simple solution to this conundrum.

他们的宇航员将留在火星上， Their astronauts will stay on Mars,

永远不再回家。 and never come home.

外面有一些组织 There are organisations out there

正在宣传单程移民的想法 who are promoting the idea of a one-way trip.

吸引了大量的关注。 There is an enormous amount of public interest in those

对我来说，也愿意看到这么多人 and, for me, it's fascinating to see the range of people

想参加这样的单程任务。 who are willing to go on such a trip.

但是把宇航员送上死亡之路的想法 But the idea of sending astronauts to their certain eventual death

有严重的道德问题 poses serious moral questions

并导致了整个航天界的严厉批评。 and has led to harsh criticism from across the space flight community.

我认为任何只把人单程送上去的任务 I think any mission that only sends people one way

在道德上是站不住脚的。 is just morally indefensible.

即使个人可能接受 Even though the individuals might themselves accept

他们只是走自己的独木桥， that they're only going to go one way,

这在道德上也是不正确的。 it's just not right morally.

但是对于凯文来说，单程去火星的想法 But for Kevin, the idea of a one-way journey to Mars

没有什么好争论的。 isn't so controversial.

这只是悠久传统的新尝试 It's just the latest in a long tradition

边境探险的巨大风险 of risky frontier expeditions

不能保证回家。 in which coming home isn't guaranteed.

当你看人类历史和探索历史的时候 When you look at human history and the history of exploration of THIS

在地球上，人们经常进行长途旅行 planet, people did often undertake very long journeys that were more

在许多方面比计划中的火星之旅更危险， hazardous in many ways than the proposed trips to Mars,

都是单程的。 that were going to be one-way.

如果你在100年前看到斯科特和阿蒙森奔向南极 If you were around 100 years ago and you saw Scott and Amundsen race to

然后你看到了斯科特的团灭的新闻， the Pole and you watched the news come in of Scott's team perishing,

你一定在想，“为什么？有什么价值？” you must have thought, "For what? For what value?"

然而，在同一个世纪的末尾， And yet, by the end of that same century,

我们从南极洲钻出的冰芯， the ice cores we were pulling out of Antarctica,

我们从气泡中提取的古大气 the paleoatmosphere that we were pulling out of the bubbles

从那些冰芯，给我们最有说服力 in those ice cores, was giving us the most convincing

我们的气候的证据 evidence yet that our climate was

以历史上从未见过的速度变暖。 warming at a rate never before seen in history.

所以，看起来是毫无意义的探险 And so, what started out as a meaningless adventure

没有人能理解，在同一个世纪末， that no-one could understand, by the end of the same century,

却成为拯救地球的关键。 became knowledge that was literally the key to saving the planet.

没有理由断言这不会发生在火星上。 There's no reason to expect that that might not happen on Mars.

南极洲的永久定居似乎是一个白日梦 Permanent settlement of Antarctica would have seemed like a pipe dream

对斯科特和阿蒙森来说。 to Scott and Amundsen.

但在100年的时间里， Yet in the space of 100 years,

我们把这个不适宜居住的角落变成了 we've made this inhospitable corner of the Earth a place

在那里我们可以长期安全地生活和工作。 where we can live and work safely for long periods.

我们能在火星上做同样的事吗- Could we do the same on Mars -

让它不仅仅是参观的景点， make it a place not just to visit,

而是可以称为家园？ but somewhere to call home?

火星生存

我只有一个选择，

我要用科学的方法来解决这个问题。

火星！ Mars!

地球以外的行星上的人类永久居住地 Permanent human habitation on a planetary body other than the Earth

是科幻小说中最流行的主题之一。 is one of science fiction's most prevalent themes.

火星表面条件相对较好 The relatively kind surface conditions on Mars

水的存在 and the presence of water

使它成为太阳系中除地球以外唯一的地方 make it the only place in the solar system other than Earth

我们可以考虑这样做 we could even consider doing it.

最终目标是将火星地球化- The ultimate goal is to terraform Mars -

把它的大气层和地面变成第二个地球 to transform its atmosphere and surface into a second Earth

可以支持地球生命。 that could support terrestrial life.

但这是一个遥远的梦想。 But it's a distant dream.

我也有感性的一面，喜欢去火星的想法 The romantic in me loves the idea of going to Mars

并最终将其地球化、绿化和殖民， and terraforming it and greening it and colonising it eventually,

因为这是技术进步的证明 because it's testament to technological progress

那就意味着我们有能力搬家 that would mean that we had moved

生活在地球摇篮之外。 beyond the so-called cradle of Earth.

火星地球化可能仍然是科幻小说的素材， Terraforming Mars may remain the stuff of science fiction,

但另一种维持生命的方法 but alternative ways to sustain life

正在认真的考虑和计划之中。 are being given serious consideration.

这些图片于2017年初发布， These images, released at the beginning of 2017,

向美国宇航局展示了如何实现这一目标的概念。 shown Nasa's concept for how it might be done.

这些未来派的圆顶是用一种意想不到的材料——冰建造的 These futuristic domes are built from an unexpected material - ice.

因为水现在被认为有充足的供应，而且水分子 With water now thought to be in plentiful supply and water molecules

对有害宇宙射线提供极好的保护， offering excellent protection from harmful cosmic rays,

也许第一批长期移民 maybe the first long-term settlers

将生活在火星上冰屋的里面。 will live in the Martian equivalent of igloos.

我能预感到这种情况 I can see that happening.

我看到我们正在开发在火星上持续生存的技术 I can see us developing technologies that allow us to persist on Mars

生存时间比我们现在想象的要长得多， for much longer periods of time than we imagine at the moment,

不必经历繁琐的步骤 without having to go through the rigmarole

改变大气层 of terraforming the atmosphere.

我们可能会达到同样的目的， We may reach that point that we may do that,

但这需要相当大的努力。 but it will take a fairly enormous effort.

对一些人来说，永久移民的前景 To some, the question of a permanent settlement

在这颗红色星球上有更多的紧迫性。 on the Red Planet has more urgency.

当我们不断消耗地球资源 As we continue to deplete the resources

改变地球的微妙平衡时，许多人认为， and alter the delicate balance of Earth, many people argue

我们需要把火星作为一条逃生路线 that we will need to settle on Mars as an escape route

逃离我们垂死的地球。 from our dying planet.

最终，地球将无法居住。不管是否是我们… Ultimately, the Earth will not be habitable. Whether or not we...

…把它搞得一团糟，在某个时候它将不适合居住。 ..we mess it up, it will not be habitable at some point.

从长远来看，如果我们希望人类能够延续下去， And long-term, if we want humans to be able to continue,

我们必须学会在其他地方生存， we do have to learn to survive elsewhere,

也不损害我们自己的星球。 but not at the detriment of our own planet.

在某种程度上， At some level or another,

必须受到道德上的谴责 it has to be morally reprehensible

如果一个物种，它的行为是毁灭一个星球 to be a species whose behaviour is that it trashes one planet

然后移到另一个，然后把那个也毁掉。 and then moves along to another one and then trashes that one.

我们不应该这样。 That's not the way we should be.

这不是我们应该做的。我们应该照顾好 That's not what we should strive for. We should look after

地球这颗最珍贵的宝石。 the very precious jewel that is our Planet Earth

我们应该负责任地探索火星。 and we should explore Mars responsibly.

嗯，可能会到一个时间，不可避免地，我们必须搬离地球， Um, there may come a time when, inevitably, we have to move planet,

但我认为，这在很远的未来。 but that's, I think, much further in the future.

无论我们与火星的长期关系如何， Whatever form our long-term relationship with Mars takes,

有几件事很清楚。 several things are clear.

去火星将是耗费天文数字、 Going to Mars will be astronomically expensive,

具有难以置信的危险和高度争议的任务。 incredibly dangerous and highly controversial.

收益真的能超过巨大的成本吗？ Can the benefits really outweigh the vast costs?

还是我们把钱花在别的事情上更好？ Or would we be better spending that money on something else?

代价

火星极地着陆者耗费每个美国人平均半个汉堡包。

一艘载人飞船也许将耗费十个汉堡包，就这样。

我想公众的某些观点， I think in some quarters of the public,

当你送人送东西上太空的时候总会有这种想法 there's this temptation to think that when you send people and things

你装载有效载荷 into space, you load the payload bays

你把大把美元钞票塞进去然后关闭 and you cram in these dollar bills and then you shut

飞船舱门，当它发射时， the payload bay doors, and as it launches,

你把钱扔到太空去了 you sort of spread that money out into space

它在重新进入时会摩擦燃烧。当然，事情不能这样想。 and it burns up on re-entry. Of course, that's not what happens.

资金压力给我们去探索红色星球的希望投下了阴影 Money casts a dark shadow over our hopes of going to the Red Planet.

仅仅把机器人降落在彗星上 Just landing a robot on a comet

罗塞塔任务花费了15亿美元。 for the Rosetta mission cost 1.5 billion.

但这算不了什么，与预期的1000亿美元 But that's nothing compared to the expected 100 billion cost

去火星的任务相比。 of a mission to Mars.

在财政紧缩的世界里， In a world of fiscal austerity,

这笔钱肯定能花得更有价值吗？ surely this money could be better spent?

海伦·沙曼不同意。 Helen Sharman disagrees.

对她来说，人类太空研究 For her, the only way human space research

能否继续吸引资金的关键就是扣人心弦的太空探险 can continue to attract funding is to tell people compelling

的故事，这意味着要派人上太空。 human stories, and that means sending people.

人们常说人类任务的价值比起 It's often been said that you'll have two to three orders

无人任务的价值 of magnitude more value from a human mission

会高出两到三个数量级， than you will from a robotic mission,

而人类任务的成本 although a human mission will only be

只比无人任务高一到两个数量级。 one to two orders of magnitude more costly.

所以事实上，人类登陆火星的价值远高于 So actually, the value of humans on Mars is so much better

火星上机器人和火星车的价值。 than the value of robots and rovers on Mars.

人与其他人密切相关。 Humans relate to other humans.

所以当人们去某个地方，谈论那里的情况时， So when humans go places and talk about what it's like there,

世界其他人都会意识到， the rest of the world realises that actually,

我们进一步探索确实有好处 there really IS benefit in us exploring further

关于那个地方的任何发现。 something about that particular place.

我们对月球的探索，六次登陆，花费了250亿美元。 Our exploration of the moon, with its six landings, cost 25 billion.

它的价值一直是争论不休的话题。 And its value has been the subject of endless debate.

对一些人来说，这是一个巨大而昂贵的面子工程。 To some, it was a colossally expensive vanity project.

但对其他人来说，好处是广泛的。 But to others, the benefits were wide-ranging.

我们今天使用的许多技术 Many of the technologies we use today

最初是为阿波罗研制的。 were originally developed for Apollo.

我们还学到了大量关于月球的知识- We also learned a huge amount about the moon -

延续至今的资产。 a legacy that continues today.

我们带回地球的三分之一吨月球岩石 The third of a tonne of moon rock we brought back to Earth will keep

让科学家们忙碌了几十年。 scientists busy for decades to come.

这些样品仍在产生新的科学研究结果- Those samples are still yielding new science results -

以及一些重大的科研成果- and major new science results -

能改变我们对月球演变的认知。 changing our understanding of the evolution of the moon.

所以，这种探索遗产带给我们不断的成功，成功，成功。 And, so, that legacy is just win-win-win continuously.

谁知道去红色行星的任务会教我们哪些关于火星的知识… Who knows what a mission to the Red Planet will teach us about Mars...

关于地球… about Earth...

甚至关于我们自己？ and even about ourselves?

对凯文来说，相比于更大想法来说钱是次要问题 For Kevin, the question of money is secondary to a much bigger idea,

就是探索本身的重要性。 and that's the importance of exploration itself.

对他来说，不去探索火星这样的目的地， For him, without exploration of destinations like Mars,

我们可能无法作为一个物种生存。 we simply might not survive as a species.

我们物种的未来确实以一种非常基本的方式决定 The future of our species does depend in a very fundamental way

探索，总是这样的，是我们一直在做的。 on exploration. It always has. It's what we've always done.

我想如果我们现在停止探索， I think if we cease in our exploration now,

我们是在停止我们作为… we are calling a halt to us as...

作为一个永久存在的物种。 as a species that persists indefinitely.

你必须去探索。 You have to explore.

你知道，这是真理，为了探索你必须生存， You know, it's a truism that to explore, you have to survive,

相反的情况也是如此——为了生存，你必须探索。 but the opposite is also true - that to survive, you have to explore.

探索的必要性，去火星和更远的地方， The necessity of exploration, to go to Mars and beyond,

是地球上一些最伟大的思想家所共有的情感。 is a sentiment shared by some of the planet's greatest thinkers.

如果人类还要延续一百万年， If the human race is to continue for another million years,

我们必须大胆地去以前没有人去过的地方。 we will have to boldly go where no-one has gone before.

扩散到太空中会有更好的效果。 Spreading out into space will have an even greater effect.

它将彻底改变人类的未来 It will completely change the future of the human race

或许可以决定我们是否还有未来。 and maybe determine whether we have any future at all.

我们可以在30年内在月球上建立基地， We could have a base on the moon within 30 years,

50年到达火星， reach Mars in 50 years,

在200年内探索外行星的卫星。 and explore the moons of the outer planets in 200 years.

把人类宇航员送上火星的想法不再是理想主义的 The idea of putting human astronauts on Mars is no longer an idealistic

梦想，它可能最终会成为现实。 dream, but one that may finally be on the verge of becoming a reality.

如果我们成功了， If we succeed,

这将是最危险和最昂贵的旅程 it will be the most perilous and expensive journey

人类曾经做到的。 humans have ever made.

我们已经在克服困难的路上了 We're already well on the way to overcoming

各种安全到达的关键技术障碍， the key technical obstacles to getting there safely,

但是否值得人类生命的代价和风险 but whether the cost and risk to human life are worth it

将继续引发激烈的辩论。 will continue to spark lively debate.

亚瑟·C·克拉克的一句话很有道理，他说我们可以 There's a lovely quote from Arthur C Clarke, where he says that we could

停止这些努力， stop in these endeavours,

但是这样做会让你退缩 but to do so would be to turn your back

几十亿年的进步， on billions of years of progress,

数百万年的人类进化， millions of years of human evolution

开始退回到他所说的 and to have begun to descend what he calls

“原始海洋海岸的斜坡。” "the slopes that end at the shores of the primordial sea."

我想真的是这样。 And I think that's true.