Mining asteroids
小行星采矿

Going platinum
小行星采矿——淘铂去

Mining metals from asteroids seems a bonkers idea. But could it work?
小行星采矿这想法听似疯狂，但行得通吗？

CAN reality trump art? That was the question hovering over the launch on April 24th, at the Museum of Flight in Seattle, of a plan by a firm called Planetary Resources to mine metals from asteroids and bring them back to Earth.
4月24日，行星资源公司（Planetary Resources）在西雅图的航天博物馆（Museum of Flight）启动了一项计划——在小行星上采矿并将矿物带回地球。对这项计划，人们一直都在疑惑：现实能否战胜艺术？

It sounds like the plot of a film by James Cameron—and, appropriately, Mr Cameron is indeed one of the company’s backers. The team behind the firm, however, claim they are not joking. The company’s founders are Peter Diamandis, instigator of the X Prize, awarded in 2004 to Paul Allen and Burt Rutan for the first private space flight, and Eric Anderson, another of whose companies, Space Adventures, has already shot seven tourists into orbit. Larry Page and Eric Schmidt, respectively the chief executive and the chairman of Google, are also involved. So, too, is Charles Symonyi, the engineer who oversaw the creation of Microsoft’s Office software (and who has been into space twice courtesy of Mr Anderson’s firm). With a cast-list like that, it is at least polite to take them seriously.
这听着就像詹姆斯?卡梅隆的电影中的情节——恰好，詹姆斯?卡梅隆实际上就是这家公司的赞助人之一。但是公司背后的团队宣称小行星采矿这事可不是在开玩笑。行星资源公司的创始人是X奖（2004年Paul Alle和Burt Rutan因首次实现私人太空飞行而获颁此奖）发起者Peter Diamandis和拥有太空探险公司（Space Adventures）（已将七位游客送上太空）的Eric Anderson。GOOGLE的总经理Larry Page和董事长 Eric Schmidt也参与其中，曾负责监督开发微软办公软件的工程师Charles Symonyi同样是其中一分子（通过Eric Anderson的公司，他也上过太空两次）。阵容如此强大，出于礼貌至少也该重视这个想法。

As pies in the sky go, some asteroids do look pretty tasty. A lot are unconsolidated piles of rubble left over from the beginning of the solar system. Many, though, are pieces of small planets that bashed into each other over the past few billion years. These, in particular, will be high on Planetary Resources’ shopping list because the planet-forming processes of mineral-melting and subsequent stratification into core, mantle and crust will have sorted their contents in ways that can concentrate valuable materials into exploitable ores. On Earth, for example, platinum and its allied elements, though rare at the surface, are reckoned more common in the planet’s metal-rich core. The same was probably true of the planets shattered to make asteroids. Indeed, the discovery of a layer of iridium-rich rock (iridium being one of platinum’s relatives) was the first sign geologists found of the asteroid impact that is believed to have killed the dinosaurs.
这想法虽不切实际，但有些小行星看来确实很诱人。它们许多是由太阳系诞生时遗留下来的碎石堆成的，结构松散；但仍有很多是过去几十亿年里小行星相互碰撞产生的碎片。特别是后者将被行星资源公司优先列在其采矿清单上。因为在行星诞生时，矿物熔化之后会层化为地核、地幔、地壳；这个过程将使其中物质分门别类，令有价值的矿物浓缩成可供开采的矿石。例如在地球上，铂和铂系元素在地表上虽然罕见，但人们认为在富含金属的地核里却是较为常见的。对于那些相互碰撞后其碎片形成小行星的行星而言，情况可能同样如此。实际上，地质学家们提出小行星曾撞击地球的第一个证据就是发现了富含铱的岩层（铱是铂的同族元素之一）。人们认为恐龙就是因小行星撞击地球而灭绝的。

Most asteroids dwell between the orbits of Mars and Jupiter. But enough of them, known as near-Earth asteroids, or NEAs, come within interplanetary spitting distance of humanity for it to be worth investigating them as sources of minerals—if, of course, that can be done economically.
大部分的小行星都位于火星和木星的轨道之间。但近地小行星（即NEAS）也不少，它们距离地球很近，值得勘探。当然，费用要划得来才行。

First catch your hare
勿谋之过早

The first thing is to locate a likely prospect. At the moment, about 9,000 NEAs are known, most of them courtesy of ground-based programmes looking for bodies that might one day hit Earth. That catalogue is a good start, but Planetary Resources plans to go further. In 2014 it intends to launch, at a cost of a few million dollars, a set of small space telescopes whose purpose will be to seek out asteroids which are easy to get to and whose orbits return them to the vicinity of Earth often enough for the accumulated spoils of a mining operation to be downloaded at frequent intervals.
首先，要找到一个可能有矿藏的小行星。目前已探明的近地小行星约有9000颗，其中大部分是地面计划在寻找可能撞击地球的天体时探测到的。从这个范围开始寻找是很好，但行星资源公司却有更远大的计划。该公司打算在2014年耗资数百万美元发射一组小型太空望远镜，用于寻找容易到达的、能经常回到地球附近的小行星，以便常将所采矿物送回地球。

That bit should not be too difficult. But the next phase will be tougher. In just over a decade, when a set of suitable targets has been identified, the firm plans to send a second wave of spacecraft out to take a closer look at what has been found. This is a significantly bigger challenge than getting a few telescopes into orbit. It is still, though, conceivable using existing technology. It is after this that the handwaving really starts.
这一步应该不会太难，但下一步就难度更大了。当该公司发现了一组适合采矿的小行星时，便计划要在短短十年多一点的时间内发送第二批宇宙飞船仔细研究一下这些小行星。这个挑战可比向太空中发射几个望远镜要艰巨得多。不过，利用现有的技术仍是可以实现的。在这之后，纸上谈兵才真正开始。

Broadly, there are two ways to get the goodies back to Earth. The first is to attempt to mine a large NEA in its existing orbit, dropping off a payload every time it passes by. That is the reason for the search for asteroids with appropriate orbits. This approach will, however, require intelligent robots which can work by themselves for years, digging and processing the desirable material. The other way of doing things is for the company to retrieve smaller asteroids, put them into orbit around Earth or the moon, and then dissect them at its leisure. But that limits the value of the haul and risks a catastrophic impact if something goes wrong while the asteroid is being manoeuvred.
要将所采矿物运回地球大致有两种方法。其一是在不改变其轨道的情况下于一颗较大的小行星上采矿，在这颗小行星每次接近地球时卸下所采矿物。这就是为何要寻找轨道合适的小行星的原因。不过，此法需要能独立工作数年的智能机器人来开采并加工有价值的矿物。其二是行星资源公司改变较小的小行星的运行轨道，将其安置在环绕地球或月球的轨道上，再在有空时仔细研究之。但那将减少每次采矿的量，且要承担移动小行星时出现问题而带来灾难性后果的风险。

Either way, the expense involved promises to be out of this world. A recent feasibility study for the Keck Institute for Space Studies reckoned that the retrieval of a single 500-tonne asteroid to the moon would cost more than $2.5 billion. Earlier research suggested that, to have any chance of success, an asteroid-mining venture would need to be capitalised to the tune of $100 billion. Moreover, a host of new technologies will be required, including more-powerful solar panels, electric-ion engines, extraterrestrial mining equipment and robotic refineries.
不论哪种方法，所需费用都一定是天价。最近，克柯太空研究所（Keck Institute for Space Studies）进行的一项可行性分析认为，将一颗重量为500公吨的小行星移到月球附近所耗资金将超过二十五亿美元。较早前的研究指出，必须投资一千亿美元才有可能实现小行星采矿。而且，还需要大量新技术，包括功率更大的太阳能电池板、电子离子引擎、太空采矿设备和自动冶炼厂。

All of which can, no doubt, be done if enough money and ingenuity are applied to the project. But the real doubt over this sort of enterprise is not the supply, but the demand. Platinum, iridium and the rest are expensive precisely because they are rare. Make them common, by digging them out of the heart of a shattered planet, and they will become cheap. The most important members of the team, then, may not be the entrepreneurs and venture capitalists who put up the drive and the money, nor the engineers who build the hardware that makes it all possible, but the economists who try to work out the effect on the price of platinum when a mountain of the stuff arrives from outer space.
当然，若为这个项目投入足够的资金和人才，以上种种都能实现。但对于这种工程浩大的项目，人们真正质疑的并非是否有人能提供这种服务，而是有没有这种需求。正因为稀有，铂、铱等矿物才价格不菲。若这些矿物能在一个由碎片构成的行星的地核中被开采到，它们就成了普通金属，价格也会变得便宜。所以，这个团队里最重要的成员可能不是推动这项事业并参与投资的企业家和风险投资人，也不是设计实现这一目的的硬件工程师；而是当大量的铂从天外而来时，那些试图算出其对铂价冲击的经济学家。