Carbon nanotube material is so light and strong that the elevator cable itself would be thinner than paper. It would literally be a ribbon, possibly several meters across, that the robotic cars would grip all the way up into space. Every year at the Space Elevator Conference, people bring carbon nanotube fibers and compete to see which can withstand the greatest strain before breaking. Winners stand to gain over a million dollars from NASA in its Strong Tether Challenge. Sadly, the year I attended, nobody had fibers that were strong enough to place (but there’s always next year!).
Researchers from the University of Cincinnati and Rice University, where there are nanomaterials labs investigating the tensile strength of carbon nanotubes, explained that we are years away from having a working elevator ribbon made of carbon nanotubes. Though the microscopic tubes on their own are the strongest material we’ve ever discovered, we need to make them into a “macromaterial”—something that’s big enough to actually build with. And making that transition into a macromaterial can be difficult, as the University of Cincinnati chemical engineer Mark Haase explained:
I like to compare [carbon nanotube development] to the development of aluminum in the first half of the twentieth century. In the years prior to this, aluminum had been known, and it was available in small labs. It was rare and expensive, but there was interest in it because it had strange properties. It was very valuable because of this. As the twentieth century started to progress, we developed the infrastructure and the technology as well as an understanding of the material itself that allowed us to mass-produce aluminum. And that’s when we started to see it infiltrating modern life in airplanes, consumer goods, and more. Carbon nanotubes are at that early stage—it’s an interesting material but very difficult and expensive to make. However, I and some of my colleagues are working on making those breakthroughs so that, much like aluminum in the second half of the twentieth century, we can develop a material that will change the modern landscape.
Haase added that the barrier here is that we need to invent an entirely new material, and then figure out how to string it between the Earth and a counterweight without it breaking. That’s not a trivial problem, even once we reach the point where we can create a carbon nanotube ribbon. What if a huge storm hits while the elevator is climbing into the stratosphere? Or what if one of the millions of pieces of junk orbiting the Earth, from bits of wrecked satellites to cast-off chunks of rockets, slams into the elevator ribbon and rips it? This may be an enormous structure, but it will have some vulnerabilities and we need to determine how we’ll protect it.
How do you dodge an incoming piece of space junk that’s headed right to your elevator ribbon? Engineer Keith Lofstrom suggested mounting the ribbon on a massive maglev platform designed to move the line in any direction very rapidly, basically yanking it out of the way. Rice University materials-science researcher Vasilii Artyukhov argued that we might not want to use carbon nanotubes at all, because they break in several predictable ways, especially when they’re under constant strain and bombarded with cosmic rays from the sun. He thought an alternative material might be boron nitride nanotubes, though these are even more experimental than carbon nanotubes at this point.
Ultimately, the elevator cable is our stumbling block in terms of engineering. But there are also social and political issues we’ll have to confront as we begin our journey into space.
Kick-starting the Space Economy
Building the elevator goes beyond engineering challenges. First, there’s the legal status of this structure. Who would it belong to? Would it be a kind of Panama Canal to space, where everybody pays a toll to the country who builds it first? Or would it be supervised by the U.N. space committees? Perhaps more urgently, there is the question of how any corporation or government could justify spending the money to build the elevator in the first place.
One of the world experts on funding space missions is Randii Wessen, an engineer and deputy manager of the Project Formulation Office at the Jet Propulsion Laboratory. An energetic man with a quick wit, Wessen has a lifetime of experience working on NASA planetary exploration missions, and now one of his great passions is speculating about economic models that would support space flight. We’ve recently witnessed the success of Elon Musk’s private company SpaceX, whose Falcon rocket now docks with the International Space Station, essentially taking on the role once played by the U.S. government–funded Space Shuttles. “The bottom line is that you need to find a business rationale for doing it,” Wessen told me. “What I would do is parallel the model that was used for the airplane.” He swiftly fills in a possible future for commercial spaceflight, by recalling how airplanes got their start:
The first thing that happens is the military wants one—they’ll fund it themselves. Next the U.S. government says this is critical to national security or economic competitiveness, so we need to make up a job for these guys to keep them in business. For airplanes, the government said, “We’ll have you deliver mail.” They didn’t need this service, but they gave it to airline companies to keep them going. This is analogous to spacecraft today. The government is saying [to companies like SpaceX], “We want you to resupply the space station.” That’s where we are now. As this gets more routine, these private companies are going to say, “If we put seats on this thing, we’ll make a killing.” They did it with airplanes. You can see that starting today, with four or five different companies who have suborbital and orbital launch capability.
Like many other people in the slowly maturing field of commercial spaceflight, Wessen is convinced that government contracts and tourism represent the first phase of an era when sending people to space is economically feasible. He noted that SpaceX’s founder, Musk, has said it’s reasonable to expect payload costs to go down to roughly $1,000 per kilogram. “Everything cracks open at that point,” Wessen declared. SpaceX isn’t the only private company fueling Wessen’s optimism. Robert Bigelow, who owns the Budget Suites hotel chain, has founded Bigelow Aerospace to design and deploy space hotels. In the mid-2000s, Bigelow successfully launched two test craft into orbit, and he is now working on more permanent orbiting habitats. Meanwhile, Moon Express, a company in Silicon Valley, is working closely with NASA and the U.S. government to create crafts that could go to the Moon. Its founders hope to have a working prototype before 2015.
Google is another Silicon Valley mainstay that is investing in the burgeoning space economy. The company recently announced its Google Lunar X Prize, which will award up to $30 million to a privately funded company that successfully lands a robot on the Moon. To win the prize, the robot must go at least 500 meters on the Moon’s soil, called regolith, while sending video and data back to Earth. Alex Hall, the senior director of the Google Lunar X Prize, described herself as “the Lunar Chamber of Commerce.” At SETICon, a Silicon Valley conference devoted to space travel, Hall told those of us in the audience that the Lunar X Prize is “trying to kick-start the Lunar Space Economy.” She said the group measures its success not just in robots that land on the Moon, but in creating incentives for entrepreneurs to set up space-travel companies in countries where no orbital launch facilities have existed before. Mining and energy companies are among the groups most interested in what comes out of the Google X Prize, she said. The X Prize “is the first step to buying a ticket to the Moon, and using the resources on the Moon as well as living there.” Bob Richards, a cofounder of Moon Express, is one of the contenders for the Google X Prize. He spoke on the same panel as Hall at SETICon, and amplified her arguments. “This isn’t about winning—it’s about creating a new industry,” he explained. “We believe in a long-term vision of opening up the Moon’s resources for the benefit of humanity, and we’re going to do it based on commercial principles.”
The space elevator is the next stage in the space economy. Once we have a relatively cheap way of getting into orbit, and a thriving commercial space industry partly located on the Moon, there will be a financial incentive to build a space elevator
—or more than one. It may begin with funding from governments, or with a space-obsessed entrepreneur who decides to invest an enormous amount of money in a “long-term vision” of the kind Richards described. Already, we see the first stirrings of how such an arrangement might work, with a future Google or Budget Suites providing the initial capital required to move the counterweight into place, drop the ribbon from space down to the ocean, and get the beam-powered robotic climber going.
Once we’ve got a reliable and sustainable method of leaving the planet, we can begin our exodus from Earth in earnest. The space elevator, or another technology like it, could be the modern human equivalent of the well-trodden path that took humans out of Africa and into what became the Middle East, Asia, and Europe. It’s the first leg on our next long journey as we scatter throughout the solar system.
22. YOUR BODY IS OPTIONAL
MOST OF US can imagine humans living in a future full of space elevators, and even cities on the Moon. But we usually picture our distant progeny in that future looking exactly the way we do now, the way people do in Star Trek. And yet of all the possible futuristic scenarios we’ve explored in this book, our continued evolution as a species is one of the most certain. We are going to evolve into creatures different from humans today—perhaps as different as we are from Australopithecus. The question is just how fast this will happen, and whether we’ll use what we know about genetics to steer the process.
This concern is especially important in the context of how humans will become a space-faring civilization. We are adapted nicely to live inside the thin layer of gas surrounding the rock we call home, but in many ways that makes us terrible space travelers. First of all, the Earth’s magnetic field protects us from the enormous amount of radiation in space, so our bodies never evolved a good defense against radiation damage. Solar radiation and high-energy particles would bombard our bodies on a regular basis in space and on places like the Moon and Mars, which have much weaker magnetic fields than we do at home. A person living off-world would have a high probability of developing cancer, infertility, or other radiation-induced problems. Another issue for people in space will be our extremely specific needs when it comes to sustenance. Because we draw our energy from foods native to Earth, it will never be a matter of humans colonizing space alone. We will have to bring a whole biosphere along with us, including plants and animals, as well as the exact mix of oxygen, nitrogen, and other gases we require to breathe. There are a host of other issues, too, such as the human body’s tendency to atrophy in low gravity, and the fact that our life spans are so short that it would take several generations to reach even the closest neighboring stars.
For all these reasons and more, it’s likely that the project of exploring space will involve a parallel project to adapt our bodies to life in environments radically different from the one where we evolved. It’s possible that we’ll become cyborgs, beings who are half biological and half machine. We may tweak our genomes to be radiation-resistant. Or we may, according to some futurists, become so technologically advanced that we’ll be able to convert the galaxy into a giant version of Earth. No matter what happens, the humans who live in space will be different from the humans on Earth today.
Changing Ourselves to Live in Space
How would we go about modifying ourselves to be more space-worthy? If anyone would know, it would be a synthetic biologist. In chapter 18, we explored how synthetic biology could revolutionize cities by providing us with buildings that could heal themselves or even grow. The field has obvious applications for any project to create humans suited for life beyond Earth as well. Leaving aside for a moment the ethical issues of engineering space-ready humans, synthetic biology could eventually reach a point where we could accurately predict how modified human genomes would function—and then implant them in the next generation. Though such knowledge may be centuries away, it’s very possible we might one day be guiding ourselves through a phase of evolution aimed at, for example, giving birth to children who could live on Mars unharmed.
To find out how this might work, I visited the UC Berkeley synthetic biologist Chris Anderson, a pioneer in the field whose research focuses in part on defining the most efficient and ethical methods for pursuing synthetic biology. A slender man with a sly smile, Anderson launched into an explanation of the future direction for synbio (as it is fondly known) by first seizing a piece of putty on his desk and vigorously smashing it between his hands. “I love this stuff!” he enthused. Apparently there is a reason the substance is sometimes marketed as “thinking putty,” because Anderson’s train of thought matched the pace at which he mashed out different shapes, which each looked like a new phylum of bacteria. Synbio researchers, he said, look at every organism in terms of its component parts. They don’t want to engineer new life-forms—not exactly. Instead, they want to engineer parts, especially at the genetic level. “Fundamentally, what we’re talking about is moving genes between organisms,” Anderson said. “We want to write whole genomes eventually. But it’s all based on components, and having the ability to predict how they will add together.”
A synbiologist looks at life-forms the same way a mechanic looks at an engine. To the mechanic, the engine is a set of interoperable parts, and some of those parts could just as easily be used in another machine. Likewise, a biological part like a gene or a protein could easily be repurposed for use in another organism. In fact, Anderson pointed out, a synbio project would typically look at a particular part—a gene, for example—in its many variants across a thousand organisms. Let’s say a synthetic biologist is studying a gene that thousands of plants use in photosynthesis. Her goal in that research would be to predict how the gene would function if it were used as a part in another organism. She would base her predictions on how the gene behaved in the thousand species where it currently exists. “This is a paradigm shift,” Anderson said. “We’ve stopped focusing on studying naturally existing things and are instead building things one gene at a time. Basically, it’s biological systems as a sum of their parts.”
Anderson’s work focuses on bacteria, and when I started to ask about modifying humans he wrinkled his nose. “I don’t touch mammalian cells,” he quipped. “They’re such a mess.” And this messiness is nothing compared with the moral quandaries presented by a future where we might use synbio to make Martians. The main problem, he said, is that we can’t experiment on humans the way we do with bacteria. To make accurate predictions about what a gene will do in a given organism, you have to run thousands of tests—some of which reveal that the gene does the opposite of what you’d hoped. “If you are playing with enhancing human intelligence, for example, you might create somebody who is brain dead rather than smart,” Anderson mused. “There would be so many accidents because this work involves a lot of fundamental uncertainty.”
Given all the risks and their consequences, he added, “It’s hard for me to see how you could even develop enough design theory to be able to safely build a human. It’s not going to be socially acceptable to tweak a human in a way that could cause them to be born grossly broken. No one’s going to go for that.” But, he conceded, it might be possible in a future where we had “a radical transformation in our ability to predict things” on the genetic level. If we had absolute certainty about how a given gene would work in a human, then the risks would be minimal. However, Anderson was extremely dubious we’d ever reach this point. He emphasized several times that he couldn’t believe that humans would ever be willing to modify our germ lines to change our species at a genetic level.
His sentiments were echoed by Claudia Wiese, a Lawrence Berkeley Lab geneticist who studies how humans respond at a cellular level to radiation in space. “During a long-duration manned space flight, substantial numbers of cells in a human body, [approximately] 30%, will be traversed by at least one highly ionizing particle track,” she told me via e-mail. “Highly ionizing particles” are the most dangerous kind of radiation we can encounter in space—these ener
getic particles shoot through the body like infinitesimally small bullets, cutting through everything in their path, including tissues and DNA. The danger is that they would damage a cell’s DNA but not kill the cell outright. Subsequently, the cell would replicate with mutated DNA, a situation that can lead to cancer.
Wiese and her colleagues believe some variants of DNA-repair genes may be better at dealing with radiation damage than others, but they’re nowhere near being able to tweak these genes to make humans radiation-proof. “I think that we are a long way away from gene therapy,” Wiese said. “At this point, the use of appropriate countermeasures”—like drugs such as antioxidants—“may be a more immediate and feasible way to mitigate the detrimental effects of space radiation.” Still, her research and that of other geneticists working with NASA suggest that we may one day know which genes control DNA repair. Once we are able to predict the behaviors of these genes, future space-farers might tweak their genes to respond quickly and effectively when bombarded with highly ionizing particles beyond Earth’s protective magnetic envelope.
But some synbio researchers aren’t sure this is a good idea. Daisy Ginsberg, a London designer who works with synthetic biologists on the ethical implications of their work, said that we could take the modification of humanity way too far. Sipping tea in a London restaurant, Ginsberg’s sunny disposition belied a deep pessimism. “I’m of the mind that we’re going to fuck everything up,” she said cheerfully. “We’re going to poison the Earth and it’s going to be unpleasant and expensive. I think we’re going to become Morlocks.” Ginsberg was referring to H. G. Wells’s novel The Time Machine, in which the author predicts that humans will evolve into two species: the Morlocks, a hyper-technological, warlike group who live underground, and the Eloi, a dim-witted but peaceful group who are prey to the Morlocks. Ginsberg was basically predicting that humans would evolve to be hideous monsters who destroy the Earth and prey upon each other. But what about modifying ourselves to live beyond Earth, so that we stop destroying our home world? Ginsberg was dubious about that, too. “I think it’s unethical to colonize space because we’ll make a mess there as well,” she said. “I’m sure we’ll be modifying everything.”
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