3D printing, and additive manufacturing processes more generally, have made many advances in recent years. Just a few years ago, most 3D printing was only used for building prototypes, which would then go on to be manufactured via conventional processes. But it’s now increasingly being used for manufacturing in its own right.
Nearly two years ago, NASA even sent a 3D printer to the International Space Station with the goal of testing how the technology works in micro-gravity. While the printer resembles a Star Trek replicator, it’s not quite that sophisticated yet; the objects it can print are small prototypes for testing.
What I really want to do is to use the machine to complete the Sagrada Familia. And to build on the moon.
NASA, the European Space Agency (ESA) and entrepreneurs aiming to jump-start human colonization of space see the 3D printing of large scale objects, including entire habitations, as a major enabling technology for the future of space exploration.
In 2013, a project led by the ESA used simulated lunar regolith – i.e. loose top soil – to produce a 1.5-ton hollow cell building block. It was conceived as part of a dome shelter for a lunar base that would also incorporate an inflatable interior structure. The project used a D-Shape printer using Enrico Dini’s company, Monolite.
Since 2011, NASA has been funding similar research led by Professor Behrokh Khoshnevies at the University of Southern California. His team has been using a technology called contour crafting, which also has the goal of using 3D printing to construct entire space habitations from in situ resources.
After testing 3D printing in space, NASA has decided the technology is close to a tipping point. As part of a new program of public/private partnerships aimed at pushing emerging space capabilities over these tipping points, NASA has awarded a major contract to the Archinaut project.
The project will see a 3D printer, built by Made in Space, mated with a robotic arm, built by Oceaneering Space Systems, with Northrup Grumman providing the control software and integration with the ISS systems.
The goal of the project is to provide an on-orbit demonstration of large, complex structure – in this case a boom for a satellite – sometime in 2018.
But 3D manufacturing is already changing the aerospace industry. Composites, for example, have become a commonly used material for a wide variety of applications.
But composites tend to suffer weakness between their laminating layers, which can lead to material failures in crucial components. 3D weaving, which deploys fibers on three axes, is set to revolutionize these materials and their performances.
But the ability to use in situ materials, both for fuel, water and construction whether on the moon, Mars, or asteroids has long been recognized as a crucial ability to enable human exploration of the solar system.
Contests such as last the 3D Printed Habitat Challenge, part of NASA’s Centennial Challenges, are an important element of an innovation strategy designed to push the envelope of technology, leveraging entrepreneurial spirit, scientific and technological know-how and design thinking in a bid to take human space exploration to the next level.
The winning design, announced at the New York Makers Faire in September, was the Mars Ice House.
The Mars Ice House Habitat, which would be printed out of ice from relatively abundant water on Mars’ northern hemisphere, is a far cry from the bunker-like spaces frequently envisioned for Mars bases. The ice would provide ample radiation protection while creating a radiant, light filled space reminiscent of a cathedral.
Space exploration has always been associated with visionary fiction and grandiose plans, and it looks like 3D manufacturing and construction may finally bring the printed word to life.
NASA’s chief scientist recently announced that “…we’re going to have strong indications of life beyond Earth within a decade, and I think we’re going to have definitive evidence within 20 to 30 years.” Such a discovery would clearly rank as one of the most important in human history and immediately open up a series of complex social and moral questions. One of the most profound concerns is about the moral status of extraterrestrial life forms. Since humanities scholars are only just now beginning to think critically about these kinds of post-contact questions, naïve positions are common.
Take Martian life: we don’t know if there is life on Mars, but if it exists, it’s almost certainly microbial and clinging to a precarious existence in subsurface aquifers. It may or may not represent an independent origin – life could have emerged first on Mars and been exported to Earth. But whatever its exact status, the prospect of life on Mars has tempted some scientists to venture out onto moral limbs. Of particular interest is a position I label “Mariomania.”
Mariomania can be traced back to Carl Sagan, who famously proclaimed
If there is life on Mars, I believe we should do nothing with Mars. Mars then belongs to the Martians, even if the Martians are only microbes.
Chris McKay, one of NASA’s foremost Mars experts, goes even further to argue that we have an obligation to actively assist Martian life, so that it does not only survives, but flourishes:
…Martian life has rights. It has the right to continue its existence even if its extinction would benefit the biota of Earth. Furthermore, its rights confer upon us the obligation to assist it in obtaining global diversity and stability.
To many people, this position seems noble because it calls for human sacrifice in the service of a moral ideal. But in reality, the Mariomaniac position is far too sweeping to be defensible on either practical or moral grounds.
Suppose in the future we find that:
Mariomaniacs would no doubt rally in opposition to any such intervention under their “Mars for the Martians” banners. From a purely practical point of view, this probably means that we should not explore Mars at all, since it is not possible to do so without a real risk of contamination.
Beyond practicality, a theoretical argument can be made that opposition to intervention might itself be immoral:
Obviously, there are a great many subtleties I don’t consider here. For example, many ethicists question whether human beings always have higher moral value than other life forms. Animal rights activists argue that we should accord real moral value to other animals because, like human beings, they possess morally relevant characteristics (for instance, the ability to feel pleasure and pain). But very few thoughtful commentators would conclude that, if we are forced to choose between saving an animal and saving a human, we should flip a coin.
Simplistic claims of moral equality are another example of overgeneralizing a moral principle for rhetorical effect. Whatever one thinks about animal rights, the idea that the moral status of humans should trump that of microbes is about as close to a slam dunk as it gets in moral theory.
On the other hand, we need to be careful since my argument merely establishes that there can be excellent moral reasons for overriding the “interests” of Martian microbes in some circumstances. There will always be those who want to use this kind of reasoning to justify all manner of human-serving but immoral actions. The argument I outline does not establish that anyone should be allowed to do anything they want to Mars for any reason. At the very least, Martian microbes would be of immense value to human beings: for example, as an object of scientific study. Thus, we should enforce a strong precautionary principle in our initial dealings with Mars (as a recent debate over planetary protection policies illustrates).
Mariomania seems to be the latest example of the idea, common among undergraduates in their first ethics class, that morality is all about establishing highly general rules that admit no exception. But such naïve versions of moral ideals don’t long survive contact with the real world.
By way of example, take the “Prime Directive” from TV’s “Star Trek”:
…no Star Fleet personnel may interfere with the normal and healthy development of alien life and culture…Star Fleet personnel may not violate this Prime Directive, even to save their lives and/or their ship…This directive takes precedence over any and all other considerations, and carries with it the highest moral obligation.
As every good trekkie knows, Federation crew members talk about the importance of obeying the prime directive almost as often as they violate it. Here, art reflects reality, since it’s simply not possible to make a one-size-fits-all rule that identifies the right course of action in every morally complex situation. As a result, Federation crews are constantly forced to choose between unpalatable options. On the one hand, they can obey the directive even when it leads to clearly immoral consequences, as when the Enterprise refuses to cure a plague devastating a planet. On the other hand, they can generate ad hoc reasons to ignore the rule, as when Captain Kirk decides that destroying a supercomputer running an alien society doesn’t violate the spirit of the directive.
Of course, we shouldn’t take Hollywood as a perfect guide to policy. The Prime Directive is merely a familiar example of the universal tension between highly general moral ideals and real-world applications. We will increasingly see the kinds of problems such tension creates in real life as technology opens up vistas beyond Earth for exploration and exploitation. If we insist on declaring unrealistic moral ideals in our guiding documents, we should not be surprised when decision makers are forced to find ways around them. For example, the U.S. Congress’ recent move to allow asteroid mining can be seen as flying in the face of the “collective good of mankind” ideals expressed in the Outer Space Treaty signed by all space-faring nations.
The solution is to do the hard work of formulating the right principles, at the right level of generality, before circumstances render moral debate irrelevant. This requires grappling with the complex trade-offs and hard choices in an intellectually honest fashion, while refusing the temptation to put forward soothing but impractical moral platitudes. We must therefore foster thoughtful exchanges among people with very different conceptions of the moral good in order to find common ground. It’s time for that conversation to begin in earnest.
Planet Earth isn’t the most ideal place for solar power to thrive. Sunsets and weather afford solar panels a significant amount of downtime.
But there’s a place not too far from here where the sun never stops shining.
A handful of researchers, and more recently the Japanese corporation Shimizu, have been gearing up to develop solar power on the moon.
Shimizu took off with the idea in 2013 in the aftermath of Japan’s 2011 Fukishima accident, which produced a political climate demanding alternatives to nuclear power plants. Shimizu’s plans call for beginning construction of a lunar solar power base as early as 2035. The solar array would be 250 miles wide and span the lunar circumference of 6,800 miles. They’re calling it the Luna Ring. Read More
For such a tiny planet, Mercury is a pretty big puzzle for researchers. NASA’s MESSENGER probe already has revealed that the planet is surprisingly rich in elements that easily evaporate from the surface, such as sulphur, chlorine, sodium and potassium. This is incredibly odd as these kind of substances most likely would disappear during a hot or violent birth – exactly the type of birth a planet so close to the sun, such as Mercury, would have had.
Scientists are also struggling to understand why Mercury is so dark and what its earliest planetary crust, created as the newly-formed planet cooled down, was made of. Research has now started to throw up answers – but these are raising a lot of new questions. Read More
The space race officially started in 1957 when the USSR launched Sputnik 1 into orbit around the Earth. This demonstration of technological prowess during the Cold War spurred US leaders in 1958 to transform the National Advisory Committee on Aeronautics into the agency we’re all familiar with: NASA. The newly minted agency needed to work quickly to reclaim the nation’s technological supremacy. NASA’s budget was increased to hire of the best scientists and engineers that money could buy. But NASA wasn’t the only red-white-and-blue pony running in the space race.
Private companies in the Land of Liberty were motivated to research, design and sell their cutting-edge technology to NASA for its future space missions. The private sector had big, bold plans to turn the US into a space-faring nation — perhaps too big. To market their ambitions, companies often turned to famed 1950s science fiction illustrator Frank Tinsley to visualize their concepts.
Some of these exciting ideas came to fruition — in a scaled-down form. However, most were left to live and die in the magazine pages where they were printed to build buzz. The concepts for many of these missions were certainly out of this world. Unfortunately, that’s the one thing they also failed to ever do. Here’s a look at some of the more notable missions that failed to launch. Read More
Well, here we are two weeks into the era of gravitational wave astronomy. I trust that by now you have read and heard all about the LIGO discovery of gravitational waves from two black holes merging and what it means for astronomy.
These are indeed exciting times and it is worth pausing to think about this announcement in the context of other big astronomical discoveries that were generations in the making. Perhaps the best historical analog for the gravitational wave search and detection is the search for the trigonometric parallax, or a method to measure the distance to stars. Its existence was long theorized, but observational evidence was harder to come by. Read More
Many of the questions I am asked regard how “true” science fiction concerning black holes might be, and whether worm holes, such as those featured in Stargate, are real or not. Invariably though, the one item that is almost assured to come up are the largely gruesome ways in which black holes might theoretically affect human beings and the Earth itself.
There are three properties of a black hole that are (in principle) measurable: their mass, their spin (or angular momentum) and their overall electronic charge. Indeed, these are the only three parameters that an outside observer can ever know about since all other information about anything that goes into making up a black hole is lost. This is known as the “no hair theorem”. Put simply: no matter how hairy or complex an object you throw into a black hole, it will get reduced down (or shaved) to its mass, charge and spin.
Of these parameters, mass is arguably the most significant. The very definition of a black hole is that it has its mass concentrated in to a vanishingly small volume – the “singularity”. And it is the mass of the black hole – and the huge gravitational forces that its mass generates – which does the “damage” to nearby objects.
One of the best known effects of a nearby black hole has the imaginative title of “Spaghettification”. In brief, if you stray too close to a black hole, then you will stretch out, just like spaghetti.
This effect is caused due to a gravitation gradient across your body. Imagine that you are headed feet first towards a black hole. Since your feet are physically closer to the black hole, they will feel a stronger gravitation pull toward it than your head will. Worse than that, your arms, by virtue of the fact that they’re not at the center of your body, will be attracted in a slightly different (vector) direction than your head is. This will cause parts of the body toward the edges to be brought inward. The net result is not only an elongation of the body overall, but also a thinning out (or compression) in the middle. Hence, your body or any other object, such as Earth, will start to resemble spaghetti long before it hits the center of the black hole.
The exact point at which these forces become too much to bear will depend critically on the mass of a black hole. For an “ordinary” black hole that has been produced by the collapse of a high mass star, this could be several hundred kilometers away from the event horizon – the point beyond which no information can escape a black hole. Yet for a supermassive black hole, such as the one thought to reside at the center of our galaxy, an object could readily sink below the event horizon before becoming spaghetti, at a distance of many tens of thousands of kilometers from its center. For a distant observer outside the event horizon of the black hole, it would appear that we progressively slow down and then fade away over time.
What would happen, hypothetically, if a black hole appeared out of nowhere next to Earth? The same gravitational effects that produced spaghettification would start to take effect here. The edge of the Earth closest to the black hole would feel a much stronger force than the far side. As such, the doom of the entire planet would be at hand. We would be pulled apart.
Equally, we might not even notice if a truly supermassive black hole swallowed us below its event horizon as everything would appear as it once was, at least for a small period of time. In this case, it could be some time before disaster struck. But don’t lose too much sleep, we’d have to be unfortunate to “hit” a black hole in the first place – and we might live on holographically after the crunch anyway.
Interestingly, black holes are not necessarily black. Quasars – objects at the hearts of distant galaxies powered by black holes – are supremely bright. They can readily outshine the rest of their host galaxy combined. Such radiation is generated when the black hole is feasting on new material. To be clear: this material is still outside the event horizon which is why we can still see it. Below the event horizon is where nothing, not even light, can escape. As all the matter piles up from the feast, it will glow. It is this glow that is seen when observers look at quasars.
But this is a problem for anything orbiting (or near) a black hole, as it is very hot indeed. Long before we would be spaghettified, the sheer power of this radiation would fry us.
For those who have watched Christopher Nolan’s film Interstellar, the prospect of a planet orbiting around a black hole might be an appealing one. For life to thrive, there needs to be a source of energy or a temperature difference. And a black hole can be that source. There’s a catch, though. The black hole needs to have stopped feasting on any material – or it will be emitting too much radiation to support life on any neighboring worlds.
What life would look like on such a world (assuming its not too close to get spaghettified, of course) is another matter. The amount of power received by the planet would probably be tiny compared to what Earth receives from the Sun. And the overall environment of such a planet could be equally bizarre. Indeed, in the creation of Interstellar, Kip Thorne was consulted to ensure the accuracy of the depiction of the black hole featured. These factors do not preclude life, it just makes it a tough prospect and very hard to predict what forms it could take.
One truism for me that I suspect holds some tiny bit of general truth for many across the broad, beautiful swath of humanity is that the longer I live the more history compresses.
Today the work Brahe, Kepler and Galileo did to understand the geometry of the solar system doesn’t seem as distant to me as the scenes from Happy Days did shortly after we landed on the moon. When I teach astronomy and physics I circle back to certain ideas repeatedly. One of these ideas is related to the evolving sense of the flow of time, wherever it may slip. This concept centers on my need to get students to come to terms with the notion that the ideas in their textbooks got there as a result of real struggles by real people. As clear and obvious as the textbook physics may appear, it almost assuredly was a dirty mess at the time. Read More
Don’t panic, future astronauts, but GMOs will probably accompany you on your adventures to deep space.
Scientists hope to genetically engineer organisms to survive off-Earth and to do some of the dirty work on spaceships and other planets. The field of study is called “space synthetic biology.” And this new frontier in genetic research could be key to opening up the final frontier.
Synthetic biology refers, generally speaking, to the work of giving some organism altered or even novel characteristics by changing its genes. Space synthetic biologists genetically alter organisms to make them more space-worthy — resistant to radiation or heat, for instance — and to make them useful to space missions — like turning Martian dirt into concrete. It sounds “out-there,” but microbes already make our planet habitable and pleasant.
“We’re breathing oxygen that was biologically produced,” says Lynn Rothschild, the head of the synthetic biology program at NASA’s Ames Research Center. “I’m wearing cotton that was biologically produced.”
We’re not going to take sheep on space missions, she clarifies, but we could take the capabilities of oxygen- and cotton-making plants and put them into the DNA of more portable life, like yeast. “Start looking at biology as technology,” she says, a “genetic hardware story” that could infuse all aspects of space missions.
Rothschild advises the Stanford-Brown team in the International Genetically Engineered Machine competition, where her groups have, among other things, made wires using DNA as a template; created a biodegradable drone; and taken genes from extreme bacteria and inserted them into E. coli to create hybrid organisms that resist extreme pH, temperature, and dryness. They called it the Hell Cell.
Such bio-based technology, according to a November report from a team led by Amor Menezes California Institute for Quantitative Biosciences in Berkeley, requires 26-85 percent less mass than “abiotic” (non-living) systems. For instance, a spaceship could carry a habitat to Mars, like the Apollo missions did to the moon, but no one wants to live in a tin can, and also that tin can is heavy.
“Think in analogy with early long-term travel on Earth,” says Rothschild, like pilgrims to North America. “They didn’t bring houses. They learned to live off the land.”
Future astronauts will have to live off of inhospitable land and also spaceships, which have no land. Menezes’s report sets forth a plan for those astronauts, suggesting directions the research could go. The microbes we use for terrestrial composting and waste treatment, for instance, produce nitrous oxide, which is spaceship go-juice. We could genetically engineer those microbes to do their duties in space, with different oxygen requirements and faster reaction capabilities but the same basic chemistry. Just by pooping and making trash, then, astronauts could create the raw material for fuel.
Once those refuse-creating colonists arrive on Mars, they could use carried-on microbes to mine the materials for building their new homes. Microbes that make acid could dissolve the Martian rock that surrounds metals, leaving just “the resource.” Or we could engineer microbes to dissolve the resource itself, so that it flows out and can then be reconstituted into a colonial outpost.
Construction companies on Mars could take the “regolith,” or surface material, and bind it together using natural glue, like mussel foot protein (engineered for optimal performance on Mars). Scientists could also make microbes that chew on the regolith and spit out calcium or iron to make “biocement.”
Poop processing, manufacturing, and construction all leave behind useful byproducts, like methane, which could help keep the colony’s lights on. The outpost, while electrified, wouldn’t have many frills. But scientists do have to ensure astronauts’ basics: air, water, and food, indefinitely.
Menezes recommends that we develop space-friendly microbes that can turn byproducts of wastewater treatment into food (yum!). While the food doesn’t have to be Michelin-star-quality, it does have to qualify as “nutrient-dense biomass that supplements astronaut dry-food while being versatile in flavor and texture.”
If the walls of a ship or colony were alive (it’s not creepy), the microbes could up-cycle carbon dioxide into oxygen and would — bonus! — shield astronauts from radiation. Not only does radiation zap our DNA with cancerous mutations, it also makes medicines expire faster.
People will still get sick in space, so synthetic biologists are also working on bio-based medical care. Microorganisms and plants could be engineered to make medicines and to shift the microbiome — the community that lives in symbiosis with each of us — back into order.
“If astronauts could grow their medicine in algae I think that would be super cool,” says Josiah Zayner, a space synthetic biologist at NASA’s Ames Research Center, who was not an author on the paper, “but I think it would take a lot of money and resources to make this happen.”
But what if the ship or colony were even more alive, Menezes wonders, full of biosensors and biological control systems? If it sounds a little too Battlestar Galactica-Cylon for comfort, don’t worry yet, says Zayner. “Honestly, I think this is just their ‘out there’ idea,” he says. “Systems that they are describing have not really been invented yet. They lost me at ‘hybrid robot version of tumor killing bacteria.’”
But it’s not that out there, contends Menezes.
“The space cybernetics grand challenge essentially calls for implementing control systems ideas into biological systems,” he says — the same control systems that put people on the moon and let Curiosity rove on Mars. But with biology. Integrating the two with technology will “take some time,” he continues, but “complete and tested space synthetic biology systems should be ready within a couple of decades, and if not in time for the first U.S. human Mars expedition, certainly by the second or third one.”
But even a cybernetic ship or colony with living walls, algae gardens, and nutrient-dense biomass isn’t quite enough for a self-sustaining, long-lived Martian habitat. To create that, we either need to make Mars a planet like Earth — or we need to make a miniature Earth on Mars.
To “terraform” a planet is to Earthify it. But “paraterraforming” is the more realistic step down: turning a smaller, contained space into a self-sustaining, human-friendly place. In the case of Mars, this would be a habitable spot surrounded by god-awful instant-death desert. Scientists would have to engineer an entire ecosystem that creates what astronauts need to eat, drink, breathe, and stay healthy, sane, and productive. All while recycling their waste products and keeping their environment cut off from the aforementioned god-awful instant-death desert — using microbes.
“This, I think should be the number-one research goal before missions to Mars,” says Zayner.
And the missions to Mars are what Menezes’ report looks toward.
“All of this is coming from the viewpoint of making it to Mars in the next 20 years and not from the viewpoint of what synthetic biology will be doing in 20 years,” says Zayner, “because that is extremely hard to plan for.” And it depends on the available of both cash and people to do the job.
Zayner also cautions that any life-based space systems will need to be tested and built years before they appear on a crewed capsule or a colony on the Red Planet. As a result, the bleeding-edge technology that exists when a Mars mission launches probably won’t be part of that Mars trip — well-characterized, older technology likely will be. That’s true in any space mission, which engineers blueprint and begin building many years before launch.
But Menezes says the gap between prototype and practical use is shrinking, largely because the space industry is no longer run entirely by a government.
“Just yesterday, I learned that there was a recent project that went from concept idea to actual space deployment within six months,” he says. “Although this timeline is atypical at the moment, with the advent of commercial space ventures, it is now possible to partner to quickly test and characterize fruitful ideas in space.”
But after the ship launches with its promising technology, problems could arise on Mars, too. The regolith that we might use for construction contains perchlorates, salts that can be toxic to humans. Toxic bricks do not an ideal colony build.
“Perchlorates are certainly a problem at the moment,” says Menezes. But we could figure out how to deal with those, and, in our initial attempts at exploiting Mars’s resources, use Mars’s air instead of its land. “For instance, 95 percent of the Mars atmosphere is carbon dioxide. This carbon dioxide will be the primary carbon source for the microbes.”
While making our own special-snowflake space biology sounds sci-fi, non-fictional scientists are working to make the concepts nonfictional, too. To engineer organisms that will be useful on other planets, they first look to our own world and its biology. And in altering and organizing those biological beasts into useful space systems, scientists will also learn how to make life better back on Earth.
“The possibilities of space synthetic biology are truly endless, yet each of them has immense importance back on Earth,” says Menezes.
Synthetic biological solutions to space problems in medicine, food, and carbon dioxide can address similar issues on Earth: personalized medicine, agriculture for growing populations, and fixing our carbon-dioxide-laden atmosphere. And while paraterraformed spaces give astronauts a safe place to sleep, the technologies can also help us learn to live sustainably on Earth. A Martian colony would be the ultimate zero-waste green space, whose ethos every earthling should get behind.
“I find the notion of doing ‘far-out space stuff’ that is simultaneously a priority on Earth really captivating and compelling,” says Menezes.
Louis Friedman has always balanced his optimistic vision for the future of human space exploration with a dose of reality, and his tempered outlook courses through his new book, Human Spaceflight From Mars to the Stars, in which he charts the distant future of human space travel.
Friedman is optimistic that human space exploration will continue well into the future. However, here’s that dose of reality from Friedman: humans will never venture beyond Mars, at least not in any historically significant way. Once humans tame Mars, how will humanity continue to explore cosmic frontiers, and to what end? Space travel, according to Friedman, will be an act more focused on transporting our minds — with the help of new technologies — rather than our bodies. Read More