Elon MuskThis documet is an abridged transcript of Elon Musk's presentation at the 68th International Astronautical Congress on September 28th, 2017 in Adelaide, Australia.本文件是 Elon Musk 于 2017 年 9 月 28 日在澳大利亚阿德莱德举行的第 68 届国际宇航大会上所作演讲的节选文字稿。
Elon MuskMAKING LIFE MULTIPLANETARY让生命成为多星球物种
Elon Musk"You want to wake up in the morning and think the future is going to be great - and that's what being a spacefaring civilization is all about. It's about believing in the future and thinking that the future will be better than the past. And I can't think of anything more exciting than going out there and being among the stars."「你希望每天早晨醒来都能觉得未来会很美好——而这正是成为太空文明的意义所在。这关乎对未来的信念，相信未来会比过去更好。我想不出有什么比走出地球、置身星际更令人兴奋的事了。」
Elon MuskBECOMING A MULTI-PLANET SPECIES成为多星球物种
Elon MuskThis presentation will cover the updated design for what we are currently calling BFR. The most important thing that I want to convey in this presentation is that I think we have figured out how to pay for it. This is very important.这次演讲将介绍我们目前称之为 BFR 的更新设计方案。我在这次演讲中最想传达的一点，是我认为我们已经想清楚了如何为它买单。这非常重要。
Elon MuskIn last year's presentation, we were really searching for the right way to pay for this thing. We went through various ideas—Kickstarter, collecting underpants, etc. These didn't pan out, but now we think we have got a way to achieve this.去年的演讲里，我们其实还在努力寻找为这件事筹资的正确方式。我们想了各种各样的点子——Kickstarter、收集内裤之类的。这些都没成，但现在我们觉得找到办法了。
Elon MuskOur updated design leverages a smaller vehicle, still pretty big but a single vehicle that can do everything that's needed for greater Earth orbit activity. Essentially we want to make our current vehicles redundant. We want to have one system—one booster and one ship—that replaces Falcon 9, Falcon Heavy and Dragon. If we can do that, then all the resources that are used for Falcon 9, Falcon Heavy and Dragon can be applied to this system. That's really fundamental.我们更新后的设计采用了一款体量更小的飞行器——当然还是相当大——但它是单一的飞行器，能够完成近地轨道之外所有活动所需的一切任务。本质上，我们希望让现有的运载工具自我淘汰。我们希望用一套系统——一个助推器加一艘飞船——来取代 Falcon 9、Falcon Heavy 和 Dragon。如果能做到这一点，那么目前用于 Falcon 9、Falcon Heavy 和 Dragon 的所有资源就都可以集中投入到这一套系统上。这是根本性的改变。
Elon MuskDEEP CRYO LIQUID OXYGEN TANK深度低温液氧储罐
Elon MuskThis giant deep cryo liquid oxygen tank is actually a twelve meter tank—you can see the relative scale of it in figure 1. It's a thousand cubic meters of volume inside. That is actually more pressurized volume than an A380, to put that into perspective. We developed a new carbon fiber matrix that is much stronger and more capable at cryo than anything before, and it holds 1200 tons of liquid oxygen.这个巨大的深度低温液氧储罐实际上是一个 12 米的储罐——图 1 中可以看到它的相对比例。内部体积达到 1,000 立方米，这实际上比 A380 的加压容积还要大。我们研发了一种全新的碳纤维基体材料，在低温环境下的强度和性能远超此前任何材料，它可以容纳 1,200 吨液态氧。
Elon MuskWe successfully tested the tank up to its design pressure and then went a little further. We wanted to see where it would break, and we succeeded in that effort. It shot about 300 feet into the air, landed in the ocean and we fished it out. At this point we have got a pretty good sense of what it takes to create a huge carbon fiber tank that can hold cryogenic liquid. That is actually extremely important for making a light spaceship.我们成功将储罐测试到了设计压力，然后继续加压。我们想看看它会在哪里破裂，结果确实做到了。它被弹射到大约 300 英尺的高空，落入海中，我们把它捞了回来。现在我们对如何制造能盛装低温液体的超大碳纤维储罐已经有了相当充分的认识。这对于制造轻质飞船来说实际上极为关键。
Elon MuskRAPTOR ENGINE TESTINGRaptor 发动机测试
Elon MuskThe next key element is on the engine side. We have to have an extremely efficient engine; the Raptor engine will be the highest thrust-to-weight engine, we believe, of any engine of any kind ever made. We already have 1200 seconds of firing across 42 main engine tests. We have fired Raptor for as long as 100 seconds. It could fire for much longer than 100 seconds, this is just a reflection of the size of the test tanks. The duration of the firing for landing on Mars is about 40 seconds. The test engine currently operates at 200 atmospheres, or 200 bar, the flight engine will be at 250 bar, and then we believe over time we could probably get that to a little over 300 bar.下一个关键要素在发动机方面。我们必须拥有一款极高效的发动机；Raptor 发动机将是我们所知的、有史以来任何类型发动机中推重比最高的。我们已经完成了 42 次主发动机测试，累计点火时长达 1,200 秒。Raptor 单次点火时间最长达到 100 秒。其实它可以点火远超 100 秒，这只是受限于测试储罐的容量。在火星上着陆时，点火持续时间约为 40 秒。目前测试发动机的工作压力为 200 个大气压，即 200 bar，飞行版发动机将达到 250 bar，我们相信随着时间推移可能还能提升到略超 300 bar。
Elon MuskPERFECTING PROPULSIVE LANDING完善推进式着陆技术
Elon MuskThe next key element is propulsive landing. In order to land on a place like the Moon where there is no atmosphere and certainly no runways, or to land on Mars where the atmosphere is too thin to land with wings even if there were runways, you really have to get propulsive landing perfect.下一个关键要素是推进式着陆。要想在月球这样没有大气层、也没有跑道的地方着陆，或者在火星这种大气层太稀薄、即便有跑道也无法靠机翼着陆的地方降落，你就必须把推进式着陆做到极致。
Elon MuskPropulsive landing is what we have been practicing with Falcon 9. As of the time of this presentation, SpaceX has had 16 successful landings and that is really without any redundancy. Falcon 9's final landing is always done with a single engine whereas with BFR, we will always have multi-engine out capability. You want minimum pucker factor on landing—you need to be able to essentially count on the landing. If you can get to a very high reliability with even a single engine, and then you can land with either of two engines, I think we can get to a landing reliability that is on par with the safest commercial airliners.推进式着陆正是我们一直通过 Falcon 9 在练习的。截至本次演讲时，SpaceX 已成功着陆 16 次，而这完全没有任何冗余保障。Falcon 9 的最终着陆始终依靠单台发动机完成，而 BFR 将始终具备多发动机失效后的着陆能力。着陆时你希望把「菊花紧缩感」降到最低——你需要能够基本确定着陆成功。如果单台发动机就能实现极高可靠性，然后还能用两台发动机中的任何一台完成着陆，我认为我们可以把着陆可靠性做到与最安全的商业客机相当。
Elon MuskFalcon 9 can also land with very high precision. In fact, we believe the precision at this point is good enough that we will not need legs for the next version. It will literally land with so much precision that it will land back on its launch mounts.Falcon 9 还能以极高的精度着陆。事实上，我们认为目前的精度已经好到下一个版本不需要着陆支架了。它会以如此高的精度着陆，直接落回到发射支架上。
Elon MuskLAUNCH RATE发射频率
Elon MuskWhen you seriously consider the idea of establishing a self-sustaining base on Mars or the Moon or elsewhere, you ultimately need thousands of ships and tens of thousands of refilling operations. This means you need many launches per day. In terms of how many landings are occurring, you need to be looking at your watch, not your calendar.当你认真考虑在火星、月球或其他地方建立自给自足基地这个问题时，最终你需要数千艘飞船和数以万计的补充燃料操作。这意味着你每天需要进行多次发射。就着陆发生的频率而言，你需要看表，而不是看日历。
Elon MuskSo while SpaceX's launch rate is quite high by conventional standards, it is still a very small launch rate compared to what will ultimately be needed.所以，尽管 SpaceX 的发射频率按照传统标准已经相当高，但与最终所需的发射频率相比，还是非常小的数字。
Elon MuskRENDEZVOUS AND DOCKING交会对接
Elon MuskThe next key technology is automated rendezvous and docking. In order to refill the spaceship in orbit, you have to be able to rendezvous and dock with the spaceship with very high precision and transfer propellant. That is one of things that we have perfected with Dragon. Dragon 1 will do an automated rendezvous and docking without any pilot control to the space station.下一项关键技术是自动交会对接。为了在轨道上为飞船补充推进剂，你必须能够以极高的精度与飞船交会对接并转移推进剂。这正是我们通过 Dragon 所完善的技术之一。Dragon 1 将在无需任何飞行员操控的情况下自动与空间站完成交会对接。
Elon MuskDragon 1 currently uses the Canadarm for the final placement onto the space station. Dragon 2, which launches next year, will not need to use the Canadarm as it will directly dock with the space station, and it can do so with zero human intervention. You just press "go" and it will dock.Dragon 1 目前使用 Canadarm 机械臂进行最后的对接定位。明年发射的 Dragon 2 将无需借助 Canadarm，直接与空间站对接，且无需任何人工干预。只需按下「出发」，它就会自动对接。
Elon MuskDragon has also allowed us to perfect heat shield technology. When you enter at a high velocity, you will melt almost anything. The reason meteors do not reach Earth is they melt or disintegrate before they reach the ground, unless they are very big. You have to have a sophisticated heat shield technology that can withstand unbelievably high temperatures and that is what we have been perfecting with Dragon—also a key part of any planet colonizing system.Dragon 还让我们完善了热防护技术。当你以高速进入大气层时，几乎什么材料都会被熔化。流星之所以无法到达地球，是因为它们在抵达地面之前就已经熔化或解体了，除非体积非常大。你必须拥有能够承受难以置信的高温的精密热防护技术，而这正是我们通过 Dragon 一直在磨练的——也是任何行星殖民系统的关键组成部分。
Elon MuskVEHICLE EVOLUTION飞行器演进历程
Elon MuskFalcon 1 is where we started out. A lot of people really only heard of SpaceX relatively recently, so they may think Falcon 9 and Dragon just instantly appeared and that's how it always was—but it wasn't. We started off with just a few people who really didn't know how to make rockets. And the reason that I ended up being the chief engineer or chief designer, was not because I wanted to, it's because I couldn't hire anyone. Nobody good would join, I ended up being that by default. And I messed up the first three launches, the first three launches failed. Fortunately the fourth launch—which was the last money that we had for Falcon 1—the fourth launch worked, or that would have been it for SpaceX. But fate liked us that day.Falcon 1 是我们的起点。很多人是最近才听说 SpaceX 的，所以他们可能以为 Falcon 9 和 Dragon 就是一下子冒出来的，一直就是这样——但事实并非如此。我们当初只有几个对火箭制造一知半解的人。我之所以最后担任了首席工程师或者说首席设计师，并不是因为我想要这个职位，而是因为我招不到人。没有优秀的人愿意加入，我就这么默认成了。而且前三次发射我都搞砸了，前三次全部失败。幸运的是第四次发射成功了——那也是我们投入 Falcon 1 的最后一笔钱——第四次成功了，否则 SpaceX 就到此为止了。但命运那天眷顾了我们。
Elon MuskSo the fourth launch worked and it's interesting—today is the ninth anniversary of that launch. I didn't realize that until I was told that just earlier today but this is a very emotional day, actually.所以第四次发射成功了，有意思的是——今天恰好是那次发射的九周年纪念日。直到今天早些时候有人告诉我，我才意识到这件事，但今天确实是非常有感情的一天。
Elon MuskFalcon 1 was quite a small rocket. When we were doing Falcon 1 we were really trying to figure out, "What is the smallest useful payload that we could get to orbit?" We thought, okay, something that could launch around half a ton to low Earth orbit. And that is how we sized Falcon 1, but it is really quite small compared to Falcon 9.Falcon 1 是一枚相当小的火箭。做 Falcon 1 的时候，我们真的在思考：「我们能送到轨道上的最小有用载荷是什么？」我们想，好，能把大约半吨的东西送到近地轨道就行。这就是我们设计 Falcon 1 的出发点，但与 Falcon 9 相比，它确实非常小。
Elon MuskFalcon 9, particularly when you factor in payload, is roughly on the order of thirty times more payload than Falcon 1. And Falcon 9 has reuse of the primary booster, which is the most expensive part of the rocket. Hopefully, Falcon 9 will soon have reuse of the fairing, the big nose cone at the front. We think we can probably get to somewhere between 70 and 80 percent reusability with the Falcon 9 system.Falcon 9，尤其是综合考虑载荷因素，运载能力大约是 Falcon 1 的 30 倍。而且 Falcon 9 实现了主助推器的重复使用，而助推器是火箭中成本最高的部分。希望 Falcon 9 很快也能实现整流罩——就是火箭前端那个大鼻锥——的重复使用。我们认为 Falcon 9 系统大概能实现 70% 到 80% 的可重复使用率。
Elon MuskFALCON HEAVYFalcon Heavy
Elon MuskHopefully, towards the end this year we will be launching Falcon Heavy. Falcon Heavy ended up being a much more complex program than we thought.希望今年年底前我们能发射 Falcon Heavy。Falcon Heavy 最终证明是一个比我们预想中复杂得多的项目。
Elon MuskIt sounds like Falcon Heavy should be easy because it's two Falcon 9 first stages strapped onto a center first stage as boosters. It is actually not easy. We had to redesign almost everything except the upper stage in order to take the increased loads. Falcon Heavy ended up being much more a new vehicle than we realized, so it took us a lot longer to get it done, but the boosters have all now been tested and they are on their way to Cape Canaveral. And we are now beginning serious development of BFR.听起来 Falcon Heavy 应该很简单，因为它就是两个 Falcon 9 一级助推器捆绑在中央一级两侧。但事实上一点都不简单。为了承受增加的载荷，我们不得不重新设计除上面级之外的几乎所有东西。Falcon Heavy 最终比我们意识到的要新颖得多，所以花了我们更长的时间来完成，但所有助推器现在都已完成测试，正在前往卡纳维拉尔角的路上。而我们现在也开始了 BFR 的认真研发。
Elon MuskWith BFR, you can get a sense of scale by looking at the tiny person in the image below. It is really quite a big vehicle. Main body diameter is about 9 meters or 30 feet and the booster is lifted by 31 Raptor engines that produce a thrust of about 5,400 tons, lifting the 4,400 ton vehicle straight up.从 BFR 的图片中，你可以通过旁边那个小小的人形来感受它的规模。这真的是一个相当大的飞行器。主体直径约为 9 米或 30 英尺，助推器由 31 台 Raptor 发动机驱动，产生约 5,400 吨的推力，将这辆重达 4,400 吨的飞行器垂直送上天。
Elon MuskBFR SHIP OVERVIEWBFR 飞船概览
Elon MuskThe ship is 48 meters in length. Dry mass is expected to be about 85 tons. Technically, our design says 75 tons but inevitably there will be mass growth. The ship will contain 1,100 tons of propellant with an ascent design of 150 tons and return mass of 50 tons. You can think of this as essentially combining the upper stage of the rocket with Dragon—it is as if the Falcon 9 upper stage and Dragon were combined.飞船长 48 米。干质量预计约为 85 吨。技术上我们的设计指标是 75 吨，但不可避免会有质量增长。飞船将携带 1,100 吨推进剂，上升时设计载荷为 150 吨，返回质量为 50 吨。你可以把它理解为本质上是将火箭的上面级与 Dragon 合二为一——就好像 Falcon 9 的上面级和 Dragon 合并成了一个整体。
Elon MuskIn figure 7, you have the engine section in the rear, the propellant tanks in the middle and then a large payload bay in the front. That payload bay is actually eight stories tall. In fact, you can fit a whole stack of Falcon 1 rockets in the payload bay. Compared to the design I showed last time, you will see that there is a small delta wing at the back of the rocket. The reason for that is to expand the mission envelope of the BFR spaceship. Depending on whether you are landing or you are entering a planet or a moon that has no atmosphere, a thin atmosphere, or a dense atmosphere, and depending on whether you are reentering with no payload in the front, a small payload, or a heavy payload, you have to balance the BFR rocket out as it is coming in. The delta wing at the back, which also includes a split flap for pitch and roll control, allows us to control the pitch angle despite having a wide range of payloads in the nose and a wide range of atmospheric densities. We tried to avoid having the delta wing but it was necessary in order to generalize the capability of the spaceship such that it could land anywhere in the solar system.在图 7 中，后部是发动机舱，中间是推进剂储罐，前部是一个巨大的载荷舱。那个载荷舱实际上有八层楼高。事实上，你可以把整整一摞 Falcon 1 火箭塞进这个载荷舱里。与我上次展示的设计相比，你会发现火箭后部有一个小型三角翼。这样做的原因是为了扩展 BFR 飞船的任务包线。无论是着陆、还是进入没有大气层、大气层稀薄还是大气层浓密的星球或卫星，也无论前部是空载、小载荷还是重载，在 BFR 下降过程中你都需要保持平衡。后部的三角翼还包含一个分裂式襟翼用于俯仰和滚转控制，让我们能够在前端载荷范围宽泛、大气密度变化巨大的情况下控制俯仰角。我们本想避免加三角翼，但为了让飞船具备在太阳系任何地方着陆的通用能力，这是必须的。
Elon MuskBFR CARGO/CABIN AREABFR 货舱/客舱区域
Elon MuskThe cargo area has a pressurized volume of 825 cubic meters—greater than the pressurized area of an A380. BFR is capable of carrying a tremendous amount of payload. In a Mars transit configuration, since you would be taking three months in a really good scenario but maybe as much as six months, you probably want a cabin, not just a seat. The Mars transit configuration consists of 40 cabins. You could conceivably have five or six people per cabin if you really wanted to crowd people in, but I think mostly we would expect to see two to three people per cabin, or about a hundred people per flight to Mars. And then there is a central storage area and galley and a solar storm shelter, entertainment area, and I think probably a good situation for at least BFR version one.货舱的加压容积为 825 立方米——超过 A380 的加压区域。BFR 能够携带极大量的载荷。在火星转运构型下，由于前往火星最理想情况需要三个月，但也可能长达六个月，你大概需要的是客舱，而不仅仅是座位。火星转运构型包含 40 个客舱。如果真的想把人塞满，每个客舱理论上可以塞进五六个人，但我认为大多数情况下我们预期每个客舱住两到三人，也就是每次飞行大约送 100 人前往火星。此外还有公共储藏区、厨房餐厅、太阳风暴避难所、娱乐区，我认为对于至少 BFR 第一版来说，这应该是个不错的安排。
Elon MuskBFR MAIN BODYBFR 主体结构
Elon MuskIn the center body of the vehicle, this is where the propellant is located—sub-cooled methane and oxygen. As you chill the methane and oxygen below its liquid point you get a fairly meaningful density increase. You get on the order of 10 to 12 percent density increase, which makes quite a big difference for the propellant load. We expect to carry 240 tons of methane (CH4) and 860 tons of oxygen.在飞行器的中央主体部分，这里存放着推进剂——深冷液态甲烷和液态氧。将甲烷和氧气冷却到液化点以下，可以获得相当可观的密度增加。密度大约能提升 10% 到 12%，这对推进剂装载量影响相当大。我们预计携带 240 吨甲烷（CH4）和 860 吨液态氧。
Elon MuskIn the fuel tank are header tanks; when you come in for landing, your orientation may change quite significantly, but you cannot have the propellant just sloshing around all over in the main tanks, you have to have the header tanks that can feed the main engines with precision. That is what you see immersed in the fuel tank on figure 7.燃料储罐内有集管储罐；进入着陆阶段时，飞行器的姿态可能发生相当大的变化，但你不能让推进剂在主储罐里随意晃动，必须有集管储罐能够精准地向主发动机供应推进剂。这就是图 7 中你看到的浸没在燃料储罐中的部分。
Elon MuskBFR ENGINESBFR 发动机
Elon MuskThe ship engine section consists of four vacuum Raptor engines and two sea-level engines. All six engines are capable of gimbaling. The engines with the high expansion ratio have a relatively smaller gimbal range and slower gimbal rate. The two center engines have a very high gimbal range and can gimbal very quickly. And you can land the ship with either one of the two center engines. When you come in for a landing, it will light both engines but if one of the center engines fails at any point, it will be able to land successfully with the other engine. Within each engine there is a great deal of redundancy as we want the landing risk to be as close to zero as possible. The sea-level engines are about 330 ISP at sea level. The upper stage engine is 375 ISP. Over time there is potential to increase that specific impulse by 5 to 10 seconds and also increase the chamber pressure by 50 bar or so.飞船发动机舱由四台真空型 Raptor 发动机和两台海平面发动机组成。全部六台发动机均可矢量偏转。高膨胀比发动机的偏转范围相对较小，偏转速率也较慢。中央两台发动机具有极大的偏转范围，偏转速度也非常快。飞船可以仅靠两台中央发动机中的任意一台完成着陆。进入着陆阶段时，两台发动机都会点火，但如果其中一台在任何时刻发生故障，另一台也能成功完成着陆。每台发动机内部都有大量冗余设计，因为我们希望着陆风险尽可能接近零。海平面发动机的比冲约为 330 ISP。上面级发动机为 375 ISP。随着时间推移，比冲有望再提升 5 到 10 秒，燃烧室压力也有望提高约 50 bar。
Elon MuskBFR REFILLINGBFR 轨道补加
Elon MuskFor refilling, the two ships would actually mate at the rear section. They would use the same mating interface that they used to connect to the booster on liftoff. We would reuse that mating interface and reuse the propellant fill lines that are used when the ship is on the booster. To transfer propellant, it becomes very simple—use control thrusters to accelerate in the direction that you want to empty. If you accelerate in this direction, propellant goes that way, and you transfer the propellant very easily from the tanker to the ship.补加推进剂时，两艘飞船实际上会在后部对接。它们将使用与飞船在发射时连接到助推器完全相同的对接接口。我们会复用这个对接接口，以及飞船与助推器连接时使用的推进剂加注管路。推进剂转移变得非常简单——用姿控推力器沿你想要排空的方向加速。你朝这个方向加速，推进剂就会向那个方向流动，推进剂就非常轻松地从加注船转移到飞船上了。
Elon MuskROCKET CAPABILITY火箭运载能力
Elon MuskFigure 8 gives you a rough sense of rocket capability, starting off at the low end with the Falcon 1 at a half-ton and then going up to BFR at 150 tons. I think it is important to note that BFR has more capability than Saturn V even with full reusability. But here is the really important, fundamental point—let us look at the launch cost.图 8 给出了火箭运载能力的大致对比，从低端的 Falcon 1（半吨）一直到 BFR（150 吨）。我认为有必要指出，BFR 即便在完全可重复使用的前提下，运载能力也超过了 Saturn V。但真正重要的、根本性的一点在这里——让我们来看看发射成本。
Elon MuskWhen you look at the vehicles against marginal launch cost, the order reverses. I know at first glance this may seem ridiculous but it is not. The same is true of aircraft. If you bought a small, single-engine turboprop aircraft—that would be one and a half to two million dollars. To charter a 747 from California to Australia is half a million dollars, there and back. The single-engine turboprop cannot even get to Australia. So a fully reusable giant aircraft like the 747 costs a third as much as an expendable tiny aircraft. In one case you have to build an entire aircraft, in the other case you just have to refuel something. It is really crazy that we build these sophisticated rockets and then crash them every time we fly. This is mad. I cannot emphasize how profound this is and how important reusability is. Often I will be told, "but you could get more payload if you made it expendable." I say "yes, you could also get more payload from an aircraft if you got rid of the landing gear and the flaps and just parachute out when you got to your destination. But that would be crazy and you would sell zero aircraft." So reusability is absolutely fundamental.当你把这些飞行器按边际发射成本排列时，顺序就反过来了。我知道乍一看这似乎荒谬，但事实并非如此。飞机也是同样的道理。如果你买一架小型单发涡桨飞机——价格大概在 150 到 200 万美元之间。而从加州包机飞 747 去澳大利亚，来回只要 50 万美元。那架单发涡桨飞机根本飞不到澳大利亚。所以一架像 747 这样完全可重复使用的大型飞机，成本只有一架一次性小型飞机的三分之一。一种情况是你得造整架飞机，另一种情况你只需要加油。我们建造这些精密复杂的火箭却每次飞完就摔掉，这真的非常疯狂。这太荒谬了。我怎么强调这一点有多深刻、可重复使用性有多重要都不为过。我常常听到有人说：「但如果做成一次性的，有效载荷可以更大。」我说：「是的，如果你把飞机的起落架和襟翼都去掉，到目的地直接跳伞，飞机的载荷也能更大。但那太疯了，你一架飞机都卖不出去。」所以可重复使用性是绝对的根本。
Elon MuskVALUE OF REFILLING轨道补加的价值
Elon MuskNow I want to talk about the value of orbital refilling. This is also extremely important. If you just fly BFR to orbit and do not do any refilling, it is pretty good—you'll get 150 tons to low Earth orbit, and have no fuel to go anywhere else.现在我想谈谈轨道推进剂补加的价值。这同样极为重要。如果你只是把 BFR 飞到轨道而不进行任何补加，它还是相当不错的——你能把 150 吨送到近地轨道，但没有燃料可以去其他地方了。
Elon MuskHowever, if you send up tankers and refill in orbit, you can refill the tanks all the way to the top and get 150 tons all the way to Mars. And if the tanker has high reuse capability, then you are just paying for the cost of propellant—the cost of oxygen and the cost of methane is extremely low. If that is all you are dealing with, the cost of refilling your spaceship on orbit is tiny and you can get 150 tons all the way to Mars. So automated rendezvous and docking and refilling are absolutely fundamental.然而，如果你派加注飞船上去进行轨道补加，把储罐全部加满，你就能把 150 吨一路送到火星。而且如果加注飞船具备高度可重复使用能力，那么你付的只是推进剂成本——氧气和甲烷的成本极其低廉。如果这就是你需要考虑的全部费用，在轨道上为飞船补加推进剂的成本是微乎其微的，而且你能把 150 吨一直送到火星。所以自动交会对接和推进剂补加是绝对的根本。
Elon MuskPAYING FOR BFR如何为 BFR 买单
Elon MuskGetting back to the question of "How do we pay for this system?" This was really quite a profound—I would not call it a breakthrough but a realization—that if we can build a system that cannibalizes our own products, makes our own products redundant, then all of the resources, which are quite enormous, that are used for Falcon 9, Falcon Heavy and Dragon, can be applied to one system.回到「我们如何为这套系统买单」这个问题上来。这其实是一个相当深刻的——我不会称之为突破，而是一种顿悟——如果我们能够建造一套蚕食我们自己产品、让我们自己的产品自我淘汰的系统，那么目前用于 Falcon 9、Falcon Heavy 和 Dragon 的所有资源——数量相当庞大——就都可以集中投入到这一套系统上。
Elon MuskSome of our customers are conservative and they want to see BFR fly several times before they are comfortable launching on it, so what we plan to do is to build ahead and have a stock of Falcon 9 and Dragon vehicles so that customers can be comfortable. If they want to use the old rocket or spacecraft, they can do that because we will have a bunch in stock but all of our resources will then turn towards building BFR; we believe that we can do this with the revenue we receive for launching satellites and for servicing the space station.我们的一些客户比较保守，他们希望在 BFR 飞行几次之后才愿意放心地用它发射，所以我们计划提前备货，建立一批 Falcon 9 和 Dragon 飞行器的库存，让客户能够安心。如果他们想用旧型号的火箭或飞船，完全可以，因为我们库里会有存货，但我们所有的资源届时都将转向建造 BFR；我们相信可以用卫星发射和空间站服务所获得的收入来支撑这一切。
Elon MuskThe size of this being a nine meter diameter vehicle is a huge enabler for new satellites. We can actually send something that is almost nine meters in diameter to orbit. For example, if you want to do a new Hubble, you could send a mirror that has 10 times the surface area of the current Hubble, as a single unit that does not have to unfold. You could send a large number of small satellites. You can actually go around and, if you wanted to, collect old satellites or clean up space debris—that may be something we have to do in the future. The fairing would open up, retract and then come back down, enabling launching of Earth satellites that are significantly larger than anything we have done before or significantly more satellites at a time than anything that has been done before.9 米直径的主体对新型卫星来说是一个巨大的赋能因素。我们实际上可以把直径接近 9 米的东西送入轨道。举个例子，如果你想建造新一代哈勃望远镜，你可以将一块反射镜面积是现有哈勃 10 倍的镜面作为单一整体发射出去，不需要展开。你可以同时发射大量小卫星。甚至如果你愿意，可以去捞取旧卫星或清理太空垃圾——这可能是我们未来不得不做的事。整流罩打开、收回，然后关上，从而能够发射比迄今为止任何飞行器都大得多的地球卫星，或者一次发射的卫星数量远超以往。
Elon MuskINTERNATIONAL SPACE STATION国际空间站
Elon MuskIt is also intended to be able to service the space station. I know it looks a little big relative to the space station but the Shuttle also looked big—so it will work. It will be capable of doing what Dragon does today in terms of transporting cargo and what Dragon 2 will do in terms of transporting crew and cargo. It can also go out to much further than that, like for example, the Moon.它还打算能够为空间站提供服务。我知道相对于空间站来说它看起来有点大，但航天飞机看起来也挺大的——所以没问题，它能用。它将具备 Dragon 目前在货物运输方面的能力，以及 Dragon 2 在人员和货物运输方面的能力。它甚至可以飞得更远，比如说，前往月球。
Elon MuskMOON MISSIONS月球任务
Elon MuskBased on our calculations, we can actually do lunar surface missions with no propellant production on the surface of the Moon. If we do a high elliptic parking orbit for the ship and retank in high elliptic orbit, we can go all the way to the Moon and back with no local propellant production on the Moon. I think that would enable the creation of Moon Base Alpha or some sort of lunar base. It is 2017. We should have a lunar base by now.根据我们的计算，我们实际上可以在月球表面不生产推进剂的情况下完成月面任务。如果我们让飞船停在高椭圆停泊轨道并在高椭圆轨道上补加推进剂，就可以全程往返月球而无需在月面进行任何本地推进剂生产。我认为这将使月球基地 Alpha 或某种形式的月球基地的建立成为可能。现在是 2017 年。我们早就应该有一个月球基地了。
Elon MuskBecoming a multi-planet species beats the hell out of being a single planet species. We would start off by sending a mission to Mars where it would be obviously just landing on rocky ground or dusty ground.成为多星球物种远比只是单星球物种强太多了。我们会从向火星发射任务开始，显然最初只是降落在岩石地面或尘土地面上。
Elon MuskMARS TRANSPORTATION ARCHITECTURE火星运输架构
Elon MuskIt is the same approach that I mentioned before, which is to send the spaceship up to orbit, refill it until it has full tanks, and then it travels to Mars and lands. For Mars you will need local propellant production. But Mars has a CO2 atmosphere and plenty of water ice. That gives you CO2 and H2O, so therefore you can make CH4 and O2 using the Sabatier Process. I should mention that, long term, this can also be done on Earth. Sometimes I get some criticism along the lines of: "Why are you using combustion in rockets and you have electric cars?" Well there is no way to make an electric rocket, I wish there was, but in the long term you can use solar power to extract CO2 from the atmosphere, combine it with water and produce fuel and oxygen for the rocket. The same thing that we're doing on Mars, we could do on Earth in the long term.方法与我之前提到的相同——把飞船送到轨道，补满推进剂，然后飞往火星并着陆。在火星上，你需要本地推进剂生产。但火星有 CO2 大气层，还有大量水冰。这给了你 CO2 和 H2O，因此你可以利用 Sabatier 过程制造 CH4 和 O2。我应该提一下，从长远来看，这在地球上同样可以做到。有时候我会受到批评，大意是：「你有电动车，为什么还在火箭上用燃烧？」好吧，没有办法造电动火箭，我希望有，但从长远来看，你可以利用太阳能从大气中提取 CO2，与水结合，生产出火箭所需的燃料和氧气。我们在火星上做的那套，未来同样可以在地球上实现。
Elon MuskFor Mars entry, you are entering very quickly, going seven and a half kilometers a second. For Mars, there will be some ablation of the heat shield, sort of like a brake pad wearing away. It is a multi-use heat shield, but unlike for Earth operations, it is coming in hot enough that you really will see some wear of the heat shield.火星进入大气层时，你的速度非常快，达到每秒 7.5 千米。对于火星来说，热防护层会有一定的烧蚀，类似于刹车片的磨损。它是一个可多次使用的热防护层，但与地球再入不同的是，它进入时的热量足够高，你确实会看到热防护层有一定磨损。
Elon MuskMARS LANDING火星着陆
Elon MuskBecause Mars has an atmosphere, albeit not a particularly dense one, you can remove almost all the energy aerodynamically. And we have proven out supersonic retropropulsion many times with Falcon 9, so we feel very comfortable about that.由于火星有大气层，尽管不是特别浓密，你可以通过气动减速去除几乎所有的动能。而且我们已经通过 Falcon 9 多次验证了超声速反推技术，对此我们非常有把握。
Elon MuskMARS MISSION GOALS火星任务目标
Elon MuskWe are targeting our first cargo missions in 2022—that's not a typo, although it is aspirational. We've already started building the system—the tooling for the main tanks has been ordered, the facility is being built and we will start construction of the first ship around the second quarter of next year. In about six to nine months we should start building the first ship. I feel fairly confident that we can complete the ship and be ready for a launch in about five years.我们的目标是在 2022 年执行首批货运任务——这不是打字错误，尽管这是一个有雄心壮志的目标。我们已经开始建造这套系统——主储罐的模具已经订购，设施正在建设中，我们将在明年大约第二季度开始建造第一艘飞船。大约六到九个月后我们应该会开始建造第一艘飞船。我相当有信心，我们能够在大约五年内完成飞船建造并做好发射准备。
Elon MuskFive years seems like a long time to me. The area under the curve of resources over that period of time should enable this time frame to be met, but if not this time frame, I think pretty soon thereafter. But that is our goal, to try to make the 2022 Mars rendezvous. The Earth-Mars synchronization happens roughly every two years, so every two years there is an opportunity to fly to Mars.五年对我来说感觉是很长的时间。那段时间内资源投入的累积效应应该能够支撑实现这个时间表，就算这次没达到，我认为应该也很快就能。但这是我们的目标，努力赶上 2022 年的火星窗口。地火同步每大约两年发生一次，所以每两年就有一次飞往火星的机会。
Elon MuskThen in 2024 we want to try to fly four ships—two cargo and two crew. The goal of the first mission is to find the best source of water, and for the second mission, the goal is to build the propellant plant. We should—particularly with six ships there—have plenty of landed mass to construct the propellant depot, which will consist of a large array of solar panels, and then everything necessary to mine and refine water, draw the CO2 out of the atmosphere, and then create and store deep cryo CH4 and O2.然后在 2024 年，我们希望尝试发射四艘飞船——两艘货运、两艘载人。第一次任务的目标是寻找最佳水源，第二次任务的目标是建造推进剂工厂。届时有六艘飞船在那里，我们应该有足够的着陆质量来建设推进剂储存设施，其中包括大规模太阳能电池阵列，以及挖掘和提炼水、从大气中提取 CO2、并生产和储存深冷 CH4 和 O2 所需的一切设备。
Elon MuskThe base starts with one ship, then multiple ships, then we start building out the city and making the city bigger, and even bigger. Over time terraforming Mars and making it really a nice place to be. It is quite a beautiful picture. You know that on Mars, dawn and dusk are blue. The sky is blue at dawn and dusk and red during the day. It's the opposite of Earth.基地从一艘飞船开始，然后是多艘飞船，然后我们开始建设城市，让城市越来越大，再越来越大。随着时间推移对火星进行地球化改造，让它真正成为一个宜居的好地方。这是一幅相当美丽的图景。你要知道在火星上，黎明和黄昏是蓝色的。天空在黎明和黄昏时是蓝色的，白天却是红色的。这和地球正好相反。
Elon MuskEARTH TO EARTH TRANSPORT地球到地球的运输
Elon MuskBut there is something else. If you build a ship that's capable of going to Mars, what if you take that same ship and go from one place to another on Earth? We looked at that and the results are quite interesting.但还有别的可能。如果你建造了一艘能够飞往火星的飞船，如果你用同一艘飞船在地球上的不同地点之间飞行呢？我们研究了这个问题，结果相当有意思。
Elon MuskMost of what people consider to be long-distance trips would be completed in less than half an hour. The great thing about going to space is there is no friction, so once you are out of the atmosphere, it will be smooth as silk. No turbulence. If we are building this thing to go to the Moon and Mars, then why not go to other places on Earth as well? Thank you.人们认为的大多数长途旅行都能在不到半小时内完成。进入太空的好处在于没有摩擦，所以一旦出了大气层，就会像丝绸一样顺滑。没有颠簸。如果我们要建造这个东西去月球和火星，那为什么不顺便用它去地球上的其他地方呢？谢谢大家。