The planet is warming, the oceans are acidifying, the Amazon is burning down, and plastic is snowing on the Arctic. Humanity’s environmental devastation is so severe, experts say, that a global-scale ecological catastrophe is already underway. Even those holding sunnier views would be hard-pressed to deny that our global footprint is presently less a light touch and more a boot stamping on Earth’s face. Against this dark background, one might ask if spending lavish sums to send humans to other worlds is a foolhardy distraction—or a cynical hedge against life’s downward spiral on this one.
Spaceflight, however, has the potential to be more than just a planetary escape hatch for eccentric billionaires. Whether in today’s Earth-orbiting spacecraft or the outposts that may someday be built on the moon and Mars, to exist beyond Earth, we must somehow replicate all of our planet’s life-giving essentials off-world. Technologies that recycle practically everything—that make water, air and food as renewable and self-sustaining as possible—are essential for current and future human spaceflight.
Then again, we already know how we are jeopardizing the planet and what needs to be done about it. “We have almost all of the tools we need to live sustainably right here, right now,” says Kate Marvel, a climate scientist at Columbia University and NASA. “Our failure to address climate change is not just because we’re interested in space.” Similarly, spaceflight alone cannot save Earth, but that does not mean it solely aids and abets naive dreams of leaving our planet behind.
Tin Can Agriculture
Astronauts need technological innovations to survive in space, but in the past, those solutions have been somewhat temporary—think of NASA’s crewed Apollo missions to the moon, which maxed out at just more than 12 days in duration. Change is afoot: the Trump administration now wants boots on the moon by 2024. Luke Roberson, senior principal investigator for flight research at NASA’s Kennedy Space Center, says the agency is pursuing sustainable architecture on the lunar surface as early as 2028—the sort requiring technology to provide long-term, regenerating caches of food, air and water.
Some of this tech may not remain in space. After all, a surprising number of inventions funded or designed by space agencies have been transferred to the commercial sector. These include several ecology-focused projects, including one to make sustainable oil and another that uses LED color combinations, or “light recipes,” to trigger different styles of crop growth.
Growing crops in space is anything but trivial. But, says Gioia Massa, a plant scientist at NASA, technologies such as specialized lighting and advanced sensors are of vital importance onboard the International Space Station (ISS), where experiments such as the Veggie system showcase energy-efficient food production. The system’s use of LEDs for plant growth was a concept conceived by NASA-funded research in the 1980s. That tech, Massa says, is now saving a lot of energy for indoor agriculture.
NASA has also worked with Florikan, a company that developed a fertilizer whose polymer coating allows for a controlled, slow release of nutrients. It is designed to reduce the runoff of fertilizer into the environment, which can cause ecological havoc. This fertilizer is being used in space, Massa says, and it has demonstrated its ability to enhance plant growth on the ISS. These products, tweaked for continued use in space, are also being marketed to commercial greenhouse owners.
Some eco-friendly innovations result from NASA simply trying to be environmentally responsible, says Daniel Lockney, who oversees the agency’s technology transfer efforts. Building spacefaring equipment on Earth is a dirty business, with fuels, paints, solvents and other toxic materials threatening to infiltrate the natural environment. That is why NASA has developed emulsified zero-valent iron (EZVI), a material that adheres to chlorinated solvents in groundwater. When dirty launchpads are scrubbed with potent chemicals, EZVI helps clean them up afterward. Beyond the launchpad, the compound has entered routine use at chemical-manufacturing plants and severely polluted Superfund sites across the country.
A supply of potable water is also paramount for both spacefarers and surface dwellers. And water pollution happens to contribute to the deaths of millions every year, so any tech that could help nix that tragedy would be welcome.
Lockney points to the microbial check valve as a solid example of how NASA can assuage this issue. Originally developed for the agency’s fleet of space shuttles, a more advanced version of the system now passively stops harmful microbes in wastewater from swimming back into potable-water reservoirs onboard the ISS. Other versions are at work right here on Earth, keeping water clean with minimal energy in areas with dirty water and without electricity access, as well as in dentists’ offices. (Remember the liquid you swish around in your mouth after a dental examination? That water is often purified by the very same valve to minimize the risk of oral infections.)
Roberson and Melanie Pickett, a postdoctoral research fellow at NASA, both work on water-purification systems for spaceflight, including on the ISS. Wastewater there is typically broken down with chemical concoctions. “But that chemistry isn’t sustainable,” Roberson says, because it requires regular refills via resupply missions from Earth. He and Pickett are now designing systems harnessing plants and microbes to recycle waste more sustainably, and these approaches may eventually help redesign toilets and septic tanks on Earth.
As is the case for water, it is far from easy to make breathable air a limitless resource in space. Up on the ISS, oxygen is traditionally extracted from water that has to be brought from Earth, which is costly and wasteful. As of 2018, the European Space Agency (ESA) is changing that status quo with its new Advanced Closed Loop System, which scrubs the Space Station’s environs of carbon dioxide and, in the process, siphons out oxygen to replenish supplies of breathable air while saving water at the same time.
Although on a far larger scale and with somewhat different operational requirements, carbon-capture systems are probably needed on Earth as part of a larger mix to slow down the pace of climate change. Technology developed for use in orbit may inform plans to do the same on our planet.
Not leaving anything to waste is the underlying principle of many of these innovations. In space, Massa says, waste must be seen as a resource, not something to mindlessly discard. That is part and parcel of so-called closed-loop systems: if such a system is perfect, all its components are recycled, and nothing is ejected from it as waste. Just think of sealed terraria, in which miniature plant ecosystems thrive by themselves for decades with no outside intervention.
The Micro Ecological Life Support System Alternative (MELiSSA) project strongly abides by that ideal. Featuring a constantly tweaked “pilot plant” test facility in Barcelona, the target of this ESA-led endeavor is to create a self-sustaining, biologically driven closed-loop life-support system.
The pilot plant, whose compartments attempt to degrade waste and use photosynthesis to clean the air, provide oxygen and produce food, employs a cohort of rats as astronaut stand-ins to see how effective the system could be at sustaining a crew for months at a time. Several generations of rats have been used, and so far, there have been zero casualties. Some MELiSSA-derived experiments, such as the photosynthesis-powered oxygen- and edible-biomass-making ARTEMISS, are being flown up to the ISS to see how they fare.
The project, started in 1989, is intended to mature into a system capable of sustaining a human crew on a long-duration interplanetary voyage by the mid-2020s. In the meantime, its spin-offs are already showing promise, says Christophe Lasseur, head of MELiSSA at ESA. For instance, its urine-recycling tech could eventually be deployed in remote places and disaster sites to provide potable water in a cost-effective manner, with minimal environmental impact, obviating the need for porting in supplies of clean water from far afield.
Lofty ideals are one thing, but the proof, as always, is in the pudding. Not all innovative ideas may become a reality, and for those that do, their development and transference from space to Earth hardly happen overnight. Roberson explains that his own inventions take, on average, seven to 10 years to be commercialized. MELiSSA is considered to be a 50-year effort.
Patience is certainly a virtue. “There’s a serendipity to it,” Lockney says. “Just like we know that water is wet, we know that investment in these new missions will yield inventions that are of benefit to all of humankind.”
If anything, these innovations underline why investment in basic R&D can be so worthwhile. “The really cool thing about science is that you really don’t know what’s going to come out of it,” Marvel says. After all, no one thought the World Wide Web would come out of the same journey that led to the Large Hadron Collider.
Lengthy engineering timescales and unpredictability aside, spaceflight has already resulted in a range of effective (if not game-changing) eco-friendly by-products for consumers. So why do they remain so relatively unknown? Chad Anderson, CEO of venture capitalist group Space Angels, suspects that it partially comes down to poor marketing.
Technology transfer from space-related R&D, Anderson says, has sparked significant innovations not only in eco-friendly products but also in the broader fields of transportation, health care and communications. The problem is that space agencies are not effectively communicating such success stories to the general public. “Space companies are notoriously bad at talking about what they are doing,” Anderson says.
Some efforts to combat this situation, Anderson says, are ironically emblematic of the overarching problem. Consider NASA’s in-house publication, Spinoff, which the space agency has used to highlight successful technology transfers since 1976. Despite that pedigree, Anderson says, the magazine remains a very technical, relatively inaccessible periodical that very few people actually read, let alone know about. To boost public engagement and recognition, Anderson recommends making more explicit and personally relatable linkages between spaceflight research and its impacts on our everyday lives.
Honey, I Shrunk the Planet
In any event, these eco innovations are welcome, but we should not rely on technological solutions to save us. Earth is already livable, Marvel says, and we should not aspire to live in tin cans. Fortunately, some research projects help us understand our planet, as well as improving our ability to survive in space.
Take the famous Biosphere 2 facility in Arizona. It was initially the site of a pioneering 1990s experiment that locked men and women in a habitat sealed off from the rest of the world to see how they and the environment within developed over the course of two years. (Earth is dubbed “Biosphere 1.”)
Although most remembered for plummeting oxygen levels that endangered the inhabitants and required outside intervention, the Biosphere 2 experiment was more successful than people may recall; it led to a better understanding of Earth’s life-support systems and a cornucopia of scientific papers. Indeed, that was the project’s original purpose: to improve our understanding of Earth’s various systems so that we might become “better stewards, overall, of the planet,” says John Adams, current deputy director of the facility, which is now owned and operated by the University of Arizona.
Today the facility consists of several model ecosystems, ranging from realistic rain forests to ocean environments. By controlling the elements within these ecosystems, scientists can understand how the real-world equivalents operate—and can be perturbed—in isolation.
At the same site but not part of the original Biosphere 2 experiment, one can find the Landscape Evolution Observatory (LEO), which consists of three massive structures build on a hillside of volcanic basalt that, in many respects, resembles Mars’s terrain. Peter Troch, the science director of Biosphere 2, explains that LEO can be used to understand how to turn a lifeless landscape into something that could sustain biology. “Typically, the physical and the biological worlds are stitched together outside, and it’s really difficult to unstitch them, understand the dynamics and stitch them back together,” Adams says. Experiments such as LEO permit this ecological dissection.
While having clear implications for understanding off-world habitats, Troch says, insights from this work could also aid the restoration of some of Earth’s most degraded ecosystems. “Between space and ground activities, we are trying to solve the same problems,” says Daniele Laurini, ESA’s head of exploration systems.
Comprehending Earth, however, is paramount. “If we can’t understand [Earth’s] systems—those we live on and among and depend on—how can we think that we’re ever going to re-create anything that’s going to support us?” Adams asks.
Space tech certainly plays a key role and not just when it comes to life-support systems. After all, satellites have allowed us to watch the planet in remarkable detail over several decades, a game-changing tool for atmospheric and environmental scientists, Marvel says.
But if we do not ensure Earth remains a livable world for many—a crisis we can already capably address—what would be the point in aiming for the stars? We may want to produce oxygen to breathe on Mars and grow salads to eat on the moon, but “Earth does all these things for us” already, Massa says. Perhaps, she speculates, the troubles of living in space might make people better appreciate the things we take for granted back home.