机器翻译,已尽力保留原意与数字
内容摘要
在博卡奇卡组装完成的星舰Mk1前,埃隆·马斯克回顾了SpaceX的历史,并展示了采用不锈钢制造、可完全重复使用的星舰。
In front of the assembled Starship Mk1 at Boca Chica, Elon Musk reviews SpaceX's history and presents the stainless-steel, fully reusable Starship.
中文实录Transcript
50 个段落
第 1 段
埃隆·马斯克:(00:21)我认为,这是我见过的最鼓舞人心的事。我只想感谢SpaceX团队和供应商,以及博卡奇卡和布朗斯维尔的人们。感谢你们的支持。还有,就是,哇,如此优秀的团队打造出了这台不可思议的飞行器,干得太了不起了。首先我想从这里说起。我的意思是,我能和这样一支优秀的团队共事,实在感到无比自豪。顺便说一句,这里风真的很大。如果你正在线观看,现场风真的很大。
第 2 段
所以,这场演示和这次活动的意义其实……包含两个方面。一个是鼓舞公众,让人们为我们在太空领域的未来感到兴奋,让人们对未来满怀热情。有太多事情值得担忧,有太多事情需要忧虑。当然,世界上有许多问题,这些问题很重要,我们需要解决它们。但我们也需要一些能让我们为活着而兴奋的事物,让我们庆幸自己早晨醒来,并对未来满怀热情,心想,是的,未来会非常美好。
第 3 段
太空探索就是这样的事情之一;成为一个航天文明,置身群星之间。这是我知道会让我庆幸自己活着的事情之一;我认为它也会让许多人庆幸自己活着。这是最美好的事情之一。我们面临一个选择:你想要哪一种未来?你想要一个我们成为航天文明、身处许多世界并置身群星之间的未来,还是一个我们永远被困在地球上的未来?我选择前者,也希望你们赞同我的选择。(02:30)
第 4 段
要让我们成为航天文明,所需的关键突破是让太空旅行变得像航空旅行一样。就航空旅行而言,你驾驶一架飞机时,会反复驾驶那架飞机。我的意思是,冒着讲废话的风险,实际上几乎所有交通工具,无论是飞机、汽车、马、自行车,都是可以重复使用的。你会多次使用那种交通工具。如果每次飞往某个地方都必须换一架新飞机,甚至返程还得再准备2架飞机,那么几乎没有人负担得起飞行。或者,如果一辆汽车只能使用一次,也几乎没有人负担得起开车。所以,必需的关键突破是一种能够快速重复使用的轨道火箭。这基本上就是太空领域的圣杯。是最根本的必需之物。
第 5 段
而这是一件非常难做到的事。按照地球的物理条件,它只是勉强可行。我的意思是,如果地球的重力稍强一点,这就不可能实现。而如果地球的重力稍弱一点,这就会相当容易。所以,我们确实正处于物理上可行与否的临界点。因此,为了制造一种能够快速重复使用且完全可重复使用的轨道火箭,你必须拥有比冲(Isp)高得惊人的发动机,也就是效率极高的发动机。
第 6 段
你还需要一种质量效率同样高得惊人的结构。然后,所有这些都需要返回发射台,能够重新加注推进剂,并像飞机一样很快再次飞行。这只是因为地球在物理上是一个相当深的引力阱,而且拥有相当厚的大气层;这是一件非常困难但并非不可能的事。但这是最根本的事情。SpaceX创立于17年前,我们设计的第一枚火箭是猎鹰1号,就是那边那个家伙。(05:00)
第 7 段
刚起步时,我们非常天真。事实上,我应该说一下原因……今天是9月28日;这是SpaceX首次进入轨道11周年纪念日。就在11年前的今天,SpaceX第一次进入了轨道。那其实是我们的第4次发射。如果那次发射没有成功,SpaceX就完了。我的钱已经花光了,也没有更多投资者,那就到此为止了。所以,如果第4次发射没有成功,那就会彻底落幕。
第 8 段
但幸运的是,那天命运眷顾了我们,我们进入了轨道。我非常尊敬任何成功进入轨道的人。那是一件很难的事。我们非常天真,显然当时在许多方面都非常天真,因为我们确实尝试过回收第一级。第一级装有降落伞,我们当时想,好吧,它重返大气层时,我们只要打开降落伞就行。然后它会降落在海洋的某个地方,我们再乘船去海里把它捞出来。这行不通。我其实还记得自己当时对降落伞供应商发火,说,你们的降落伞根本没用。不,这不是他们的错。
第 9 段
火箭从太空返回时,第一级会以大约,你知道,10至12马赫的速度飞来,撞上大气层就像撞上一堵混凝土墙,然后“砰”的一声。所以,你实际上必须仔细调整火箭的姿态。你必须配备气动翼面,还必须实施再入点火来降低速度。然后,你必须引导它穿过大气层,再进行动力着陆。我们为此尝试了许多、许多次。
第 10 段
我们其实制作过一段视频,一部收录我们所有失败经历的花絮集锦,而失败次数很多。(07:30)我想,我们可能尝试了大约14次之类的,最终才成功让火箭着陆。如果我们转到下一张幻灯片,你们可以看一下……——这是“蚱蜢”,那实际上是猎鹰9号。很难看出它的尺度,但那是一台猎鹰9号大小的助推器,装有1台发动机和带巨型减震器的大型支腿;我们根本不知道自己在做什么。
第 11 段
埃隆·马斯克(画外音):令人惊讶的是,“蚱蜢”受伤为零;“蚱蜢”仍然活着。
第 12 段
埃隆·马斯克:他们有猎鹰1号;你们刚才看到的是一台猎鹰9号大小的飞行器。真正让人很难从直觉上理解的是,这艘巨舰将完成“蚱蜢”做过的同样事情。大约1或2个月后,这个东西将起飞,飞到65,000英尺,也就是大约20公里的高度,然后返回并着陆。所以那个庞然大物——看到它起飞再返回,确实会相当震撼。然后希望,是的,……(掌声)——是的,太疯狂了。
第 13 段
这是一种相当激进的……我稍后会在演示中谈到;它,这是控制火箭的一种相当新颖的方法——更像跳伞者,而不是飞机。但我稍后会讲到。(10:00)所以,从猎鹰1号到猎鹰9号,再到我们发射的猎鹰重型……其实,猎鹰重型的首次发射只是在去年2月。所以,距离猎鹰重型首次发射才过去大约1年半,当时我们完成了2枚并排助推器的着陆。我一直很喜欢这段视频。它是我的朋友乔纳制作的。
第 14 段
是的。其实我从没想过那会发生。(12:30)我很高兴它发生了。有些人会说,等等,我们为什么要放一辆Roadster和那名宇航员,你知道,Starman。其实,这源于我和朋友乔纳的一次讨论。当时我在他的厨房里,我说,你知道,通常他们发射火箭时,会发射一块混凝土石块,但这听起来不怎么鼓舞人心。所以,你觉得我们能发射的最有趣的东西是什么?他说,嗯,你为什么不发射你的Tesla?我说,这主意太棒了。
第 15 段
我的另一位朋友,她说:“为什么不在仪表盘上放一辆微型Tesla?”所以,我们在仪表盘上放了一辆微型Tesla,微型Tesla里还有一个微型Starman。这只是为了迷惑未来的外星人。他们会说,这到底是什么?你知道,就是想要某种能够激发想象力、让人们对太空感到兴奋的东西。
第 16 段
那么,来看看星舰。显然,你们就在那边就能真正看到它。这里有一张图片,更准确地说是一张渲染图。它大约高50米,也就是大约165英尺左右。
第 17 段
其实,我注意到这里的飞船干质量有误;非常抱歉。我倒希望是85吨。这艘飞船的干质量必须约为120吨。最初的1马赫原型机接近200吨,而在批量生产时,我认为它可能会达到大约120吨。如果我们真的非常幸运,也许能降到110吨;99吨会超级震撼。所以,就其用途而言,它能在完全可重复使用的情况下,将大约150吨送入轨道并返回。
第 18 段
对于完全可重复使用来说,这是一个非常大的数字。我们有信心,非常初期的版本将能超过100吨,但我认为有一条明确的路径可以达到150吨。完全可重复使用系统的成本基本上就是(15:00)推进剂的成本,而推进剂主要是氧气。每1吨燃料对应3.5吨氧气。所以,与猎鹰架构相比,这一架构的优势之一是,实际上我们每单位燃料使用的氧气更多,而不是更少。Merlin或猎鹰架构是每1吨燃料对应大约2.5吨氧气。这个则是每1吨燃料对应3.5吨氧气。所以它上升时,实际上主要装的是液氧,因为当你到达真空环境时,基本上就没有空气了。
第 19 段
那么,下一张幻灯片。之前我谈到了星舰如何再入,以及如何控制它。
第 20 段
它与其他任何东西都很不一样。它实际上是在下落,所以我们是在进行受控下落。对于火箭,你实际上是在试图弄坏它,而不是……你是在试图产生阻力而不是升力,它确实与飞机正好相反。你希望产生尽可能大的阻力。而且你也需要一些升力,尤其是在高层大气中时,主要是为了让你不会……你可以控制最大加热速率。你需要足够的升力,让自己保持在大气层中密度较低的部分,从而消耗掉速度。基本上,它是这样,如果这是地球,它会以大约60度的角度前进。
第 21 段
我的手就是火箭——它正以大约60度的角度前进。所以在轨道上时,你实际上是以大约25倍音速相对于地面水平飞行。这是一个非常重要、但与我们正常日常生活中的直觉相悖的概念。处于轨道上、处于零重力状态,与高度无关。它关乎速度。你水平方向前进得有多快?当某个物体处于轨道上时,它正以极快的速度绕地球飞行,以至于向外的加速度,也就是径向向外的加速度,等于重力向内的加速度。然后你就有了零重力。这就是你实际上会处于零重力状态的原因。
第 22 段
人们常以为空间站是静止的,(17:30)但实际上它正以25倍音速,也就是大约每小时17,000英里的速度绕地球运行。它在照片里看起来总是静止不动。而且由于那里没有空气,你不必采用符合空气动力学的结构。所以它完全可以是一种疯狂的结构,看起来根本不应该能以25倍音速飞行,但它确实可以。而且你只能感受到加速度。你感受不到速度。人们有时会问,以25倍音速飞行是什么感觉?其实什么感觉都没有。只有加速到那个速度的过程会让你有所感觉。
第 23 段
那么,星舰正这样飞来——这个平台就是地球——它以高超音速飞来,大致呈60度角。它就这样飞来,然后开始下落,接着像跳伞者一样直接下坠,同时控制着自己——然后它转向并像那样着陆。这个解释复杂得难以置信。你可以从那里体会一下。这个好多了。
第 24 段
就是这样。看,一回事。亲眼看到那东西着陆会显得完全疯狂。对,那会很疯狂。
第 25 段
那么,我们来谈谈猛禽发动机。飞船总共会有6台发动机。
第 26 段
其中3台是海平面型猛禽发动机,而它们现在实际上就在火箭上。所以,我们有3台海平面型……事实上,那就是一张从内部拍摄的照片——里面就是那个样子。所以,我们有3台海平面型猛禽发动机,它们可以进行万向摆动,也就是说整台发动机会移动。因此,火箭转向的方式就是移动整台发动机。而飞机发动机是固定的,你通过移动控制面来改变方向,例如副翼、方向舵、升降舵和襟翼……——火箭——当发动机点火时,你通过移动整台发动机来转向。星舰将配备3台海平面发动机,它们最多可以摆动约15度;另有3台真空发动机,针对轨道中的效率进行了优化,它们不会移动。它们将被直接固定在原位。
第 27 段
这样一来,我们就能为真空型猛禽发动机配备最大的钟形喷管。(20:00)理想情况下,真空发动机的目标比冲是380秒。这是一个非常……——用太空极客的说法,这真的是一个很棒的数字。即使对于钢合金发动机来说,比冲超过350秒也确实非常出色。所以实际上……——抱歉,我正在看这里的幻灯片,而你们没有看到。所以,我说“里面看起来就是那样”指的就是这个……——往回翻一张幻灯片。那就是星舰目前的内部。
第 28 段
这就是它在底部的样子。好了。然后是隔热罩。
第 29 段
我已经经历了多个版本的隔热罩设计。解决这个问题有很多种办法。
第 30 段
最终,我们决定让隔热罩采用六边形瓷砖,也就是陶瓷瓦片,在微观结构层面基本上就像微小的玻璃粉丝。非常轻,但抗裂性很强——本质上是玻璃瓦片。而且,因为星舰采用钢制结构……——一开始,感觉会是:“哦,它是钢制的。这是不是意味着它很重?”不,实际上,它是最轻的结构。我认为这整个项目中最好的设计决策就是采用301不锈钢。因为在低温下,301不锈钢实际上与先进复合材料或铝锂合金的有效强度大致相同。与大多数在低温下会变脆的盗窃不同,301不锈钢会变得强得多。
第 31 段
而且,如果它处于超硬状态,也就是经过冷轧达到超硬状态,它也会变得强得多。实际上,它在低温下的强度重量比与先进复合材料或铝锂合金相当,甚至可能略胜一筹。这一点没有得到充分认识。(22:30)因为如果你只是查看材料手册,然后问,比如,不锈钢的强度是多少?它看起来比实际弱得多。如果你问,低温下的强度是多少?哦,强得多;在极低温度下,几乎是原来的2倍。那时,它就会变得优于碳纤维或铝锂合金。
第 32 段
而这还有另一个好处:它的熔化温度也很高。所以,对于一艘可重复使用的飞船来说,你会像流星一样进入。你需要一种不会在低温下熔化的材料。你需要一种在高温下才会熔化的材料。而钢在这一点上也极其出色。钢的熔化温度大约是1500摄氏度,而铝,你知道,可能是300或400度,碳纤维也是如此。而且那确实已经是在挑战极限了。
第 33 段
拥有高得多的熔化温度意味着飞船进入时,你不需要在背风侧设置任何防护。而迎风侧——高温侧——所需的防护则大幅减少,因为对于可重复使用系统来说,瓦片的厚度实际上——取决于背壳温度,也就是与机身接触的瓦片背面会有多热。而因为钢能承受高得多的温度,所以即使在迎风侧,你的隔热罩也会轻得多。但最终效果是,301不锈钢火箭实际上是最轻的可重复使用架构。
第 34 段
然后说到成本。我们使用的碳纤维是每吨130美元。钢是每吨2,500美元。哦,抱歉,是每吨130,000美元,对比每吨2,500美元。这样合理多了。碳纤维每吨130,000美元,钢每吨2,500美元。所以,钢的成本约为碳纤维的2%。所以,我们把材料从碳纤维改成钢,绝对是件好事。(25:00)而且不锈钢非常容易焊接,证据就是我们没有工厂,直接在户外完成了焊接。团队的技术非常出色,但使用碳纤维,这是不可能的;使用铝锂合金,也不可能。但钢很容易焊接,而且能经受自然环境。
第 35 段
而且,实际上,(……25:36),比如在火星上,你可以把它切开,可以焊接,可以改造。没问题。是的。这个观点很好。你身处月球或火星;你会想要一种能够改造、能够切开并用于其他用途的东西。那肯定是件很棒的事。所以无论如何,钢——显然我爱上钢了;你知道,我不得不这么说。那么,让我们看看,接下来讲助推器。
第 36 段
所以,助推器的设计最多可容纳37台猛禽发动机。我不确定我们是否会达到那么多,但确实可以有31台。我认为你会需要的最少数量可能在24台左右。但助推器的设计允许拆下多台发动机,所以你实际上可以按自己的需要增加或减少发动机。你基本上只需要很大的向上推力。随着时间推移,我认为你可能会想要一枚推力约为7,500吨的火箭,这大约是土星5号推力的2倍,略高于2倍;总起飞质量约为5,000吨,推重比约为1.5。
第 37 段
对于可重复使用火箭,你实际上需要较高的推重比,而不是像消耗型火箭那样需要较低的推重比,因为任何低于1的推重比都没有用;比如,如果你的推力小于你的重量,你就不会移动。所以,对于可重复使用火箭,你实际上需要较高的推重比。这是一项非常重要的(27:30)设计优化变化。所以,这就是为什么我认为更多发动机可能是好事,而且随着时间推移,推力要达到约7,500吨,推重比达到1.5或更高。
第 38 段
我们认为可能会调整栅格翼,将其设计成某种菱形。看起来更酷。效果也更好。然后,后部的翼实际上只是支腿。它们并不是稳定或制导所必需的。它们基本上就是用作支腿。
第 39 段
好了。那么我们来看看一些开发测试。这是一次猛禽发动机点火。
第 40 段
好了。然后,很显然,我们在星虫上进行过一次猛禽发动机点火。是的。
第 41 段
仅凭画面有点难以体会它的尺度,但它的直径与星舰相同。而且显然,它就在那边。所以,你很难判断它是垃圾桶那么大,还是,你知道,它究竟有多大,但它大约……主体直径约为9米或30英尺,这还不包括支腿的跨度。(30:00)是的。所以,这让你对它的尺寸有个概念。
第 42 段
所以,那里的小像素……那些小像素是一个人。然后旁边是星虫,再用千年隼作对比,然后是星舰,也就是你们眼前看到的这个。然后是完整堆叠后的样子,其高度几乎是这艘飞行器的2.5倍。这个模拟会让你对这些东西的尺度有个概念。
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埃隆·马斯克(画外音):这让我有点想起《太空炮弹》中的一个场景。
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埃隆·马斯克(画外音):这是轨道补加燃料。轨道补加燃料对于前往火星和月球、在月球或火星上建立城市极其重要。这是至关重要的一步。
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一枚可快速重复使用的轨道运载火箭是……一枚可快速重复使用的火箭是实现——头韵——太空进入成本突破所必需的;也就是不要每次飞行都把火箭扔掉。但另一个关键步骤是在轨道上补加燃料,这样星舰就可以携带,比如说,150吨用于月球、火星或更远目的地的有效载荷进入轨道。然后,它可以接受燃料补给,把推进剂贮箱装满,从而能携带1,200吨推进剂离开近地轨道(35:00)。这非常重要,因为这样你的速度增量就足以将约150吨运送到月球或火星表面,同时实现完全重复使用和轨道补加燃料。
第 46 段
轨道补加燃料实际上是SpaceX与空间站对接操作的简化版本。所以,与空间站对接实际上比轨道补加燃料更难,但在练习与空间站对接的过程中,SpaceX也学会了如何在复杂环境中于轨道上交会和对接。所以,这是最终在月球和火星上建立基地、建立城市所需的另一个关键拼图。是的,所以这些就是关键要素。因此,我们认为在月球上建立基地会非常令人兴奋。
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即便它只是一个科学基地……——例如,我们在南极洲有一个基地。许多国家都在南极洲设有用于科学研究的基地,而这里会成为一片不可思议的研究区域。所以,无论人们是否想住在月球上,都肯定有大量科学工作可做。而且我认为它也很近。所以,做这件事会相当令人兴奋。然后,当然,我们还可以前往太阳系中的其他地方,比如土星。但我认为,我们需要关注的关键事项,是以最快的路径在火星上建成一座自给自足的城市。这是根本所在。
第 48 段
据我们所知,我们是外界存在的唯一意识或唯一生命。也许还有其他生命,但我们没有看到任何迹象。人们经常问我,你对外星人之类的事情知道些什么,而我就会说,老兄,我告诉你,我相当确定,如果有外星人,我会知道。我没有看到任何外星人的迹象。那要是军方把外星人藏在51区之类的地方呢,你知道;这是一个很流行的梗。(37:30)嗯,我告诉你:增加国防经费最大、最快的办法,就是抛出类似这样的话:“嘿,我们发现了一个外星人。”(……37:40)类似于,“啊,国防肯定能拿到更多钱了”。保证如此,那里(……37:46)会在2秒内就像展品一样被摆出来。现实是,据我们所知,这里是唯一的地方,至少在银河系的这一部分或银河系内,是唯一存在意识的地方。而我们用了很长时间才走到这一步。
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你知道,根据地质记录,地球已经存在了大约45亿年,不过其中大约5亿年,它基本上都是熔融岩浆。所以,但是尽管如此,至少存在细菌生命的时间也有数十亿年,而多细胞生命则存在了数亿年。但有趣的地方在这里。太阳正逐渐变得更热、更大,随着时间推移,即使不存在全球变暖——人为造成的那种——太阳也会膨胀,并使地球过热。我猜大概……——以人类的时间尺度来看,这是很长的时间,但只剩下数亿年了。就这些,这就是我们拥有的全部时间。好吧。数亿年。但从某种进化角度来看,基本上,如果有意识生命在地球上的进化多花10%的时间,它就根本不会进化出来,因为它早已被太阳焚毁。
第 50 段
我要说的是,意识似乎是一种非常稀有且珍贵的事物,而我们应该采取一切力所能及的措施来保存意识之光。这扇窗口直到现在才打开——经过45亿年,这扇窗口才打开。等待的时间非常漫长,而它可能不会敞开太久。我天性相当乐观,但存在某种可能,存在某种可能,这扇窗口不会敞开太久。我认为,我们应该趁这扇窗口敞开时成为一个多行星文明。而且如果我们做到了,我认为地球可能迎来的结果甚至会更好,因为届时火星有朝一日可以帮助地球。因此,我认为我们真的应该竭尽全力成为一个多行星物种,并将意识扩展到地球之外。而且我们现在就应该这样做。谢谢。(40:13)
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Elon Musk: (00:21) This is, I think, the most inspiring thing that I’ve ever seen. And I just like to thank the SpaceX team and the suppliers, and the people of Boca Chica and Brownsville. Thank you for your support. And, just like, wow, what an incredible job by such a great team to build this incredible vehicle. First of all I want to start with that. I mean, I’m just so proud to work with such a great team. And it’s really windy here, by the way. If you’re watching this online, it is really windy.
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So, the point of this presentation and this event is really… there are two elements to it. One is to inspire the public, get people excited about our future in space, and get people fired up about the future. There are so many things to worry about, so many things to be concerned about. There are many troubles in the world, of course, and these are important, and we need to solve them. But we also need things that make us excited to be alive, that make us glad to wake up in the morning and be fired up about the future and think, yeah, the future is going to be great.
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This space exploration is one of those things; and becoming a spacefaring civilization being out there among the stars. This is one of the things that I know it makes me glad to be alive; I think it makes many people glad to be alive. It’s one of the best things. We are faced with a choice: Which future do you want? Do you want the future where we become a spacefaring civilization and are in many worlds and are out there among the stars or one where we are forever confined to Earth? And I say it is the first and I hope you agree with me. (02:30)
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The critical breakthrough that’s needed for us to become a spacefaring civilization is to make space travel like air travel. So, with air travel, when you fly a plane, you fly that plane many times. I mean, the risk of stating the obvious, it really almost any motor transport, whether it’s a plane or a car, a horse, a bicycle is reusable. You use that motor transport many times. If you had to get a new plane every time you flew somewhere and even get to have two planes for the return journey, very few people could afford to fly. Or if you could use a car only once, very few people could afford to drive a car. So, the critical breakthrough that’s necessary is a rapidly reusable orbital rocket. This is basically the Holy Grail of space. The fundamental thing that’s required.
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And it is a very hard thing to do. It’s only barely possible with the physics of Earth. I mean, if Earth’s gravity was a little heavier, it would be impossible. And if Earth’s gravity was a little lighter, it would be quite easy. So, we’re really right on the cusp of what is physically possible. So, in order to create a rapidly reusable rocket and fully reusable orbital rocket, you have to have engines that have incredibly high, specific impulse (Isp), that essentially are extremely efficient.
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You need to have a structure that is also incredibly mass efficient. And then that all needs to come back to the launch pad and be able to be refilled with propellant and flown again very quickly, just like an aircraft. It’s just because of the physics of Earth being quite a deep gravity well and having quite a thick atmosphere; this is a very tough but not impossible thing. But it is the most fundamental thing. With SpaceX, we started out 17 years ago, and the first rocket we designed was the Falcon 1, which was that guy right there. (05:00)
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When we started off, we were very naive. And in fact, the reason I should say… it’s September 28th; this is the 11th anniversary of the first time SpaceX reached orbit. Eleven years ago today, SpaceX made orbit for the first time. It was actually our fourth launch. And if that launch had not succeeded, that would have been the end of SpaceX. I’d run out of money, there were no more investors, and that would have been it. So, if that fourth launch had not succeeded, that would have been curtains.
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But fortunately, fate smiled on us that day, and we made it to orbit. I have great respect for anyone who makes it to orbit. That is a hard thing. We were very naive, obviously very naive on many levels back then, because we did actually try to recover the first stage. The first stage had a parachute on it, and we thought, okay, we’ll just pop the parachute when it comes back into the atmosphere. Then it’ll land somewhere in the ocean, and we’ll go fish it out of the ocean with a boat. This does not work. I actually remember getting mad at the parachute supplier, like, your parachute doesn’t work. Nah, it wasn’t their fault.
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When the rocket comes in from space, that first stage is coming in like, you know, Mach 10 to 12, and it hits the atmosphere like it’s a concrete wall and ‘boom’. So, you actually have to orient the rocket carefully. You have to have aerodynamic surfaces, and you have to do an entry burn to slow it down. Then you’ve got to guide it through the atmosphere and then do a propulsive landing. This took us many, many attempts.
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We actually did a video, a blooper reel of all the times we failed, which was a lot. (07:30) I think it might have taken us like 14 attempts or something before we finally successfully landed the rocket. If we’ve gone to the next slide, you can take a look at… – This is Grasshopper, that’s actually Falcon 9. It’s hard to tell the scale, but that’s a Falcon 9 size booster with one engine and big legs with giant shock absorbers; we didn’t know what the heck we were doing.
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Elon Musk (voice-over): Now amazingly, Grasshopper had zero blessures; Grasshopper is still alive.
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Elon Musk: They have Falcon1; what you saw there was a Falcon 9 size vehicle. What’s really kind of hard to grasp at a visceral level is that this giant ship will do the same thing that Grasshopper did. This thing is going to take off, fly to 65,000 feet, about 20 kilometers, and come back and land in about one or two months. So that giant thing – it’s really going to be pretty epic to see that thing take off and come back. And then hopefully, yeah, …(applause) – Yeah, it’s wild.
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This is a quite radical… I’ll talk about it later in the presentation; it’s, this is quite a new approach to controlling a rocket – much more akin to a skydiver than a plane. But I’ll talk about that later. (10:00) So, going from Falcon 1 to Falcon 9 to Falcon Heavy, which we launched… actually, the first launch of Falcon Heavy was only February of last year. So, it’s only been about a year and a half since the first Falcon Heavy launch when we did two side-by-side booster landings. And I always liked this video. It was done by my friend Jonah.
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Yeah. I never thought that would happen, actually. (12:30) I’m glad that it did. Some people were like, wait, why do we have the Roadster with the astronaut, you know, Starman. Actually, this came from a discussion with my friend Jonah. I was at his kitchen, and I was like, you know, normally when they do a rocket launch, there’s a launch of a rock of concrete, but that doesn’t sound very inspiring. So, what do you think the most sort of fun thing is that we could launch? And he was like, well, why don’t you launch your Tesla? And I was like, that’s a great idea.
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And another friend of mine, she said: “Why don’t you put a tiny Tesla on the dashboard?” So we put a tiny Tesla on the dashboard with a tiny Starman in the tiny Tesla. This is just to confuse the aliens in the future. They’ll be like, what the heck is this? You know, just want something that captures the imagination, gets people excited about space.
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So, let’s see Starship. You can really see it right there, obviously. There’s a picture, more a rendering. It’s about 50 meters, sort of 165 feet or so.
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Actually, I notice we have an error in our ship dry mass here; my apologies. I wish it was 85 tons. This ship dry mass has to be approximately 120 tons. The initial Mach 1 prototype is closer to 200 tons, and in series production, I think it’ll probably be about 120 tons. If we get really lucky, it might get down to 110; 99 would be super epic. So, in terms of its usefulness, it’ll be able to do about 150 tons with full reusability to orbit and back.
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This is a very big number for full reusability. The very initial versions, we’re confident will do over a 100 tons, but I think there’s a clear path to 150 tons. The cost of a fully reusable system is basically (15:00) the cost of the propellant, which is mostly oxygen. This is three and a half tons of oxygen for every one ton of fuel. So, one of the advantages of this architecture over the Falcon architecture is that we actually use more oxygen per unit of fuel rather than less. Merlin or the Falcon architecture is about two and a half tons of oxygen for every one ton of fuel. This is three and a half tons of oxygen for every one ton of fuel. So when it ascends, it’s really mostly liquid oxygen because when you get to vacuum, there’s no air, basically.
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So, the next slide. Earlier I was talking about how Starship enters and how it’s controlled.
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It’s quite different from anything else. It’s really falling, and so we’re doing a controlled fall. With a rocket you’re actually trying to break as opposed to… you’re trying to create drag instead of lift, it’s really the opposite of an aircraft. You want the most amount of drag that you can produce. And you want some lift, especially when you’re in the upper atmosphere, mostly so that you don’t… you can control the maximum heating rate. You want enough lift to keep yourself high in the low-density portion of the atmosphere, so you can burn off velocity. Basically, it goes like, if this is the Earth, it goes at about a 60 degree.
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My hand is the rocket – it’s going at about 60 degrees. So when in orbit, you’re actually going at around 25 times the speed of sound horizontal to the ground. This is a very important concept that is counterintuitive to our normal daily life. Being in orbit, being in zero G is not about altitude. It’s about velocity. How fast are you going – horizontally? When something’s in orbit, it’s zooming around the Earth so fast that the outward acceleration, outward radial acceleration, is equal to the inward acceleration of gravity. And then you have zero gravity. This is why you actually have zero gravity.
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People often think the Space Station is stationary, (17:30) but it’s actually going around the world at 25 times the speed of sound or about 17,000 miles an hour. It always looks stationary in the pictures. And since there’s no air, you don’t have to have an aerodynamic structure. So it can be a totally crazy structure that doesn’t look like it should be able to go 25 times the speed of sound, but it does. And you can only feel the acceleration. You can’t feel velocity. People sometimes wonder, what does it feel like to go 25 times the speed of sound? Actually, it feels like nothing. Only accelerating to there feels like something.
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So, the Starship is coming in – this platform is the Earth – it’s coming in at hypersonic velocity like this, sort of around a 60-degree angle. So, it comes like this and then starts falling and then just falls like a skydiver, and it’s just controlling itself – and then it turns and lands like that. That’s an incredibly elaborate explanation. There you can get a sense for it. This is much better.
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There you go. See, same thing. It’ll look totally nuts to see that thing land. Yeah, that’ll be crazy.
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So let’s talk about the Raptor engine. The ship will have a total of six engines.
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Three of the sea-level variety of Raptor, and those are actually on the rocket right now. So, we have the three sea-level… in fact, that’s a picture of just inside – that’s what it looks like. So, we’ve got the three sea-level Raptor engines, and they gimbal, which means that the whole engine moves. So, the way the rocket steers is by moving the entire engine. Whereas an aircraft engine is static, and you move by moving the control surfaces, like the ailerons and rudder and elevator and flaps… – The rocket – when the engines are powered, you moved the entire engine to steer it. The Starship will have three sea-level engines that move up to about 15 degrees angle and three vacuum engines that are optimized for efficiency in orbit that will not move. They will be just fixed it in place.
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And that allows us to have the biggest bell nozzle (20:00) for the vacuum Raptor engines. Aspirationally, the target is a 380 second Isp for the vacuum engine. This is a very… – In sort of space geek terms, this is like really a great number. And even for the steel alloy engines to get over a 350 second Isp is also really great. So actually… – sorry, I’m looking at the slide here, and you’re not. So, that’s what I meant by ‘it looks like that on the inside’… – go back one slide. That’s the inside of the Starship right now.
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That’s what it looks like in the base. All right. Then heat shield.
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I’ve gone through various iterations of heat shield. There’s a lot of ways to skin the cat here.
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Ultimately, we decided to have heat shield hexagonal tiles, ceramic tiles, basically like a tiny glass vermicelli at a microstructure level. Very light, but very crack resistant – essentially glass tiles. And there, because Starship is a steel construction… – At first, it feels like, “Oh, it’s steel. Does that mean it’s heavy?” No, actually, it’s the lightest construction. I think the best design decision on this whole thing is 301 stainless steel. Because at cryogenic temperatures, a 301 stainless actually has about the same effective strength as an advanced composite or aluminum-lithium. Unlike most steals, which get brittle at low temperatures, 301 stainless gets much stronger.
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And if it’s in the extra hard condition, meaning it’s cold-rolled to extra hard condition, it also gets way stronger. Actually, its strength-to-weight ratio at cryogenic temperatures is equivalent, or even perhaps slightly better than advanced composites or aluminum-lithium. This is not well appreciated. (22:30) Because if you just look at the materials manual and say like, what is the strength of stainless steel? It looks much weaker than it is. If you say, what is the strength at cryogenic temperature? Oh, much stronger; at very low temperature, almost twice as strong. That’s when it becomes better than carbon fiber or aluminum-lithium.
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And this is another benefit: It also has a high melting temperature. So, for a reusable ship, you’re coming in like a meteor. You want something that does not melt at a low temperature. You want something that melts at a high temperature. And this is where steel is extremely good as well. Steel has a melting temperature around sort of 1500 degrees centigrade whereas aluminum, you know, maybe 300 or 400 degrees, and same thing for carbon fiber. And that’s really pushing it.
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Having that much higher melting temperature means that you don’t need any shielding on the leeward side of the ship when it comes in for entry. And the shielding you need on the windward side – the hot side – is massively reduced because the thickness of the tile is actually for a reusable system – It’s dependent on what back shell temperature, like how hot does the back of the tile that interfaces with the airframe get. And because the steel can take a much higher temperature, your heat shield, even on the windward side, is much lighter. But the net effect is that a 301 stainless steel rocket is actually the lightest possible reusable architecture.
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Then, to come to cost. The carbon fiber we were using was $130 a ton. The steel is $2,500 a ton. Oh, sorry, $130,000 a ton versus $2,500 a ton. That makes much more sense. It’s $130,000 a ton for the carbon fiber and $2,500 a ton for the steel. So, the steel is about 2% of the cost of the carbon fiber. So, this is a good thing we changed from carbon fiber to steel, by far. (25:00) And it’s very easy to weld stainless steel, the evidence being that we welded it outdoors without a factory. Great skills by the team, but with carbon fiber, this is impossible; with aluminum-lithium, also impossible. But steel is easy to weld, and it is resilient to the elements.
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And also, actually, (… 25:36), like on Mars, you can cut that up, you can weld it, you can modify it. No problem. Yeah. That’s a good point. You’re out there on the Moon or Mars; you want something that you can modify, that you can cut up and use for other things. That’s like for sure a great thing. So anyway, steel – obviously I’m in love with steel; I had to say it, you know. So, let’s see, going on to the booster.
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So, the booster is designed to take up to 37 Raptor engines. I’m not sure if we’ll go that high, but you can really have 31. I think the minimum number you’d want is maybe around 24. But the booster is designed to be able to take multiple engines out, so you can actually add or subtract engines as you’d like. You basically just need a lot of force pushing up. Over time, I think you probably want around a 7,500 ton force rocket which is about twice the thrust of a Saturn V, a little more than twice the thrust, and on a roughly 5,000 ton gross liftoff mass for roughly one and a half thrust-to-weight.
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For a reusable rocket, you actually want a high thrust-to-weight rather than with an expendable rocket, where you want a low thrust-to-weight, because any thrust-to-weight below one is not useful; like, if you have a less thrust than your weight, you don’t move. So, you actually want a high thrust-to-weight for a reusable rocket. This is a very important (27:30) design optimization change. So that’s why I think more engines are probably good and getting up to around 7,500 tons over time and a one and a half thrust-to-weight ratio, or more.
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We think we’re probably going to adjust the grid fins designed to be kind of like a diamond shape. It looks cooler. It works better too. And then the rear fins are actually just legs. They’re not needed for stabilization or guidance. They’re essentially there for legs.
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All right. So let’s go into some of the development testing. This is a Raptor firing.
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All right. And then, obviously, we had a Raptor fire on the Starhopper. Yeah.
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It’s kind of hard to see it to appreciate scale, but it’s the same diameter as the Starship. And obviously, it’s just right over there. So, it’s kind of hard to tell if it’s the size of a trashcan or, you know, how big it is, but it’s about… the body diameter is about 9 meters or 30 feet and not including the legs span. (30:00) Yeah. So, this gives you a sense of size.
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So the little pixel there… little pixels are a human. And then there’s the Hopper next to it, the Millennium Falcon for comparison, then Starship, which is what you see before you. And then what it will look like with the full stack, which is almost two and a half times as tall as this vehicle. This simulation will give you a sense of the scale of things.
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Elon Musk (voice-over): It slightly reminds me of a scene from Spaceballs.
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Elon Musk (voice-over): This is the orbital refilling. Orbital refilling is extremely important for getting to Mars and getting to the Moon to establish a city on Moon or Mars. This is a vital step.
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A rapidly reusable orbital launcher rocket is… a rapidly reusable rocket is required for – alliteration – for getting a breakthrough in cost of access to space; that you don’t throw the rockets away every flight. But another key step is refilling on orbit so that Starship can get to orbit with, let’s say, 150 tons of payload for the Moon or Mars or beyond. And then it can get tanked up to fill up its propellant tanks and so that it can depart from low Earth orbit (35:00) with 1,200 tons of propellant. This is a very big thing so that your delta velocity is enough to transport about 150 tons to the surface of the Moon or Mars with full reusability and orbital refilling.
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The orbital refilling is actually a simplified version of what SpaceX does in docking with the Space Station. So it’s actually harder to dock with the Space Station than it is to do orbital refilling, but in practicing docking with the Space Station, SpaceX has also learned how to rendezvous and dock in orbit in a complex environment. So this is one of the other critical pieces of the puzzle needed to establish a base on the Moon and Mars, a city, ultimately. And yeah, so those are the critical ingredients. So, we think it will be very exciting to have a base on the Moon.
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Even if it’s just a science base that… – for example, we have a base at Antarctica. Many countries have bases in Antarctica for science research, and this would be an incredible area for research. So whether or not people want to live on the Moon, there’s definitely a lot of science to be done. And I think it’s close as well. So, that would be quite exciting to do. And then, of course, we can go to other places in the solar system like Saturn. But the critical thing that we need to focus on, I think, is the fastest path to a self-sustaining city on Mars. This is the fundamental thing.
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As far as we know, we are the only consciousness or the only life that’s out there. There might be other life, but we’ve seen no signs of it. And people often ask me, what do you know about the aliens and that, and I’m like, man, I tell you, I’m pretty sure I’d know if there were aliens. I have not seen any sign of aliens. And what if the military is hiding aliens in area 51 or something, you know; that’s a popular meme. (37:30) Well, let me tell you: the biggest, the fastest way to increase defense funding would be to bring up like, “Hey, we found an alien.” (…37:40) like, “Ah, there’s more money for defense, definitely”. Guaranteed, there (…37:46) would be like on display in two seconds. The reality is, as far as we know, this is the only place, at least in this part of the galaxy or in the Milky Way, where there is consciousness. And it’s taken a long time for us to get to this point.
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You know, according to the geological records, Earth has been around for about four and a half billion years, although it was mostly molten magma for about half a billion years. So, but still, several billion years with at least bacterial life and multicellular life for several hundred million years. But here’s the interesting part. The sun is gradually getting hotter and bigger, and over time even in the absence of global warming – man-made stuff – the sun will expand, and it will overheat the Earth. My guess is probably… – On human timescales, this is a long time, but there are only several hundred million years left. That’s all, that’s all we got. Okay. Several hundred million years. But sort of from an evolutionary standpoint, basically, if it took an extra 10% longer for conscious life to evolve on Earth, it wouldn’t evolve at all because it would have been incinerated by the sun.
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What I’m saying is that it appears that consciousness is a very rare and precious thing, and we should take whatever steps we can to preserve the light of consciousness. The window has been opened only now – after four and a half billion years, is that window open. That’s a long time to wait, and it might not stay open for long. I’m pretty optimistic by nature, but there’s some chance, there’s some chance that window will not be open for long. I think we should become a multi-planet civilization while that window is open. And if we do, I think the probable outcome for Earth is even better because then Mars could help Earth one day. And so I think we should really do our very best to become a multi-planet species and to extend consciousness beyond Earth. And we should do it now. Thank you. (40:13)