穆斯克如何在火星上建设“自给自足的城市”？

Humanity will go extinct unless it reaches for the stars and colonizes a new planet.

如果不能找到新的恒星，移民新的行星，人类终将走向灭绝。

That’s what Elon Musk says, at least. The tech billionaire wrote a new paper detailing his vision for a “self-sustaining city” on Mars that was published in the scientific journal New Space earlier this month and posted online Wednesday.

至少埃隆·穆斯克是这样说的。这位科技行业的亿万富翁在本月早些时候的《新太空》（New Space）杂志上发表了一篇论文，详细阐述了在火星建设“自给自足的城市”的愿景。这篇论文周三被发布在网上。

The 16-page commentary details ideas the SpaceX CEO has been mulling over for years and most recently presented at the International Aeronautical Congress in Mexico last September. But his outline for the journey is now available in print, complete with accompanying charts and illustrations. Now, the scientific community will be able to scrutinize the proposal at its convenience.

这篇共16页的论文详细介绍了SpaceX CEO过去几年一直在思考的一些想法，总结了他在去年9月份墨西哥国际宇航联大会（International Aeronautical Congress）上的演讲内容。现在他把对火星之旅的大概想法变成了文字，还配上了图表和插图。这将更方便科学界研究他的火星移民计划。

Musk writes the paper in such a candid manner that he almost makes the roughly 140 million mile trip seem easy. ” There really is a way that anyone could go if they wanted to,” he says. The main obstacle, Musk argues, is the high cost of transporting people to the red planet. Using traditional methods like the approach that was used to send men to the moon in 1969, he estimates that it would cost about $10 billion per ticket. Musk has a much more feasible target in mind.

穆斯克的论文非常直白，在他的笔下，这段大约1.4亿英里的旅程似乎没有太大难度。他说道：“实际上有一种方法可以让想要移民火星的人们得偿所愿。”穆斯克表示，目前的主要障碍是将人类运往火星的高昂运输成本。他估计，如果使用传统方法，例如1969年将人类送上月球所使用的方法，每张票的成本将高达100亿美元。但穆斯克心中有一个更可行的目标。

“If we can get the cost of moving to Mars to be roughly equivalent to a median house price in the United States, which is around $200,000, then I think the probability of establishing a self-sustaining civilization is very high,” Musk writes. “I think it would almost certainly occur.”

他写道：“只要我们能将前往火星的成本降到相当于美国一套普通住房的价格，也就是大约200,000美元，我认为在火星上建设自给自足的人类文明的可能性是非常高的。我想这一定能实现。”

In order to achieve that price point, Musk outlines several steps to improve the cost of Mars travel by “five million percent”: Spaceships must be fully reusable, they should be able to refuel in orbit, and then once again on Mars with fuel that is yielded from production plants built on the planet. Musk states that methane is the ideal propellant because the technical challenges to harvest it on Mars are significantly easier than substances like hydrogen, which he says is too expensive.

为了将火星之旅的成本降低“五百万个百分点”，穆斯克列出了几个步骤：宇宙飞船必须完全可以重复使用，可以在地球轨道上填充燃料，而在火星上建设的生产设备将生产燃料供飞船使用。穆斯克认为甲烷是理想的火箭推进剂，因为在火星上制作甲烷的技术难度要低于提取氢或其他物质的难度。他认为氢燃料的成本过高。