What’s the Right Way to Regulate Gene-Edited Crops?
In the next few decades, humanity faces its biggest food crisis since the invention of the plow. The planet's population, currently 7.6 billion, is expected to reach 10 billion by 2050; to avoid mass famine, according to the World Resource Institute, we'll need to produce 70 percent more calories than we do today.
Imagine that a cheap, easy-to-use, and rapidly deployable technology could make crops more fertile and strengthen their resistance to threats.
Meanwhile, climate change will bring intensifying assaults by heat, drought, storms, pests, and weeds, depressing farm yields around the globe. Epidemics of plant disease—already laying waste to wheat, citrus, bananas, coffee, and cacao in many regions—will spread ever further through the vectors of modern trade and transportation.
So here's a thought experiment: Imagine that a cheap, easy-to-use, and rapidly deployable technology could make crops more fertile and strengthen their resistance to these looming threats. Imagine that it could also render them more nutritious and tastier, with longer shelf lives and less vulnerability to damage in shipping—adding enhancements to human health and enjoyment, as well as reduced food waste, to the possible benefits.
Finally, imagine that crops bred with the aid of this tool might carry dangers. Some could contain unsuspected allergens or toxins. Others might disrupt ecosystems, affecting the behavior or very survival of other species, or infecting wild relatives with their altered DNA.
Now ask yourself: If such a technology existed, should policymakers encourage its adoption, or ban it due to the risks? And if you chose the former alternative, how should crops developed by this method be regulated?
In fact, this technology does exist, though its use remains mostly experimental. It's called gene editing, and in the past five years it has emerged as a potentially revolutionary force in many areas—among them, treating cancer and genetic disorders; growing transplantable human organs in pigs; controlling malaria-spreading mosquitoes; and, yes, transforming agriculture. Several versions are currently available, the newest and nimblest of which goes by the acronym CRISPR.
Gene editing is far simpler and more efficient than older methods used to produce genetically modified organisms (GMOs). Unlike those methods, moreover, it can be used in ways that leave no foreign genes in the target organism—an advantage that proponents argue should comfort anyone leery of consuming so-called "Frankenfoods." But debate persists over what precautions must be taken before these crops come to market.
Recently, two of the world's most powerful regulatory bodies offered very different answers to that question. The United States Department of Agriculture (USDA) declared in March 2018 that it "does not currently regulate, or have any plans to regulate" plants that are developed through most existing methods of gene editing. The Court of Justice of the European Union (ECJ), by contrast, ruled in July that such crops should be governed by the same stringent regulations as conventional GMOs.
Some experts suggest that the broadly permissive American approach and the broadly restrictive EU policy are equally flawed.
Each announcement drew protests, for opposite reasons. Anti-GMO activists assailed the USDA's statement, arguing that all gene-edited crops should be tested and approved before marketing. "You don't know what those mutations or rearrangements might do in a plant," warned Michael Hansen, a senior scientist with the advocacy group Consumers Union. Biotech boosters griped that the ECJ's decision would stifle innovation and investment. "By any sensible standard, this judgment is illogical and absurd," wrote the British newspaper The Observer.
Yet some experts suggest that the broadly permissive American approach and the broadly restrictive EU policy are equally flawed. "What's behind these regulatory decisions is not science," says Jennifer Kuzma, co-director of the Genetic Engineering and Society Center at North Carolina State University, a former advisor to the World Economic Forum, who has researched and written extensively on governance issues in biotechnology. "It's politics, economics, and culture."
The U.S. Welcomes Gene-Edited Food
Humans have been modifying the genomes of plants and animals for 10,000 years, using selective breeding—a hit-or-miss method that can take decades or more to deliver rewards. In the mid-20th century, we learned to speed up the process by exposing organisms to radiation or mutagenic chemicals. But it wasn't until the 1980s that scientists began modifying plants by altering specific stretches of their DNA.
Today, about 90 percent of the corn, cotton and soybeans planted in the U.S. are GMOs; such crops cover nearly 4 million square miles (10 million square kilometers) of land in 29 countries. Most of these plants are transgenic, meaning they contain genes from an unrelated species—often as biologically alien as a virus or a fish. Their modifications are designed primarily to boost profit margins for mechanized agribusiness: allowing crops to withstand herbicides so that weeds can be controlled by mass spraying, for example, or to produce their own pesticides to lessen the need for chemical inputs.
In the early days, the majority of GM crops were created by extracting the gene for a desired trait from a donor organism, multiplying it, and attaching it to other snippets of DNA—usually from a microbe called an agrobacterium—that could help it infiltrate the cells of the target plant. Biotechnologists injected these particles into the target, hoping at least one would land in a place where it would perform its intended function; if not, they kept trying. The process was quicker than conventional breeding, but still complex, scattershot, and costly.
Because agrobacteria can cause plant tumors, Kuzma explains, policymakers in the U.S. decided to regulate GMO crops under an existing law, the Plant Pest Act of 1957, which addressed dangers like imported trees infested with invasive bugs. Every GMO containing the DNA of agrobacterium or another plant pest had to be tested to see whether it behaved like a pest, and undergo a lengthy approval process. By 2010, however, new methods had been developed for creating GMOs without agrobacteria; such plants could typically be marketed without pre-approval.
Soon after that, the first gene-edited crops began appearing. If old-school genetic engineering was a shotgun, techniques like TALEN and CRISPR were a scalpel—or the search-and-replace function on a computer program. With CRISPR/Cas9, for example, an enzyme that bacteria use to recognize and chop up hostile viruses is reprogrammed to find and snip out a desired bit of a plant or other organism's DNA. The enzyme can also be used to insert a substitute gene. If a DNA sequence is simply removed, or the new gene comes from a similar species, the changes in the target plant's genotype and phenotype (its general characteristics) may be no different from those that could be produced through selective breeding. If a foreign gene is added, the plant becomes a transgenic GMO.
Companies are already teeing up gene-edited products for the U.S. market, like a cooking oil and waxy corn.
This development, along with the emergence of non-agrobacterium GMOs, eventually prompted the USDA to propose a tiered regulatory system for all genetically engineered crops, beginning with an initial screening for potentially hazardous metaboloids or ecological impacts. (The screening was intended, in part, to guard against the "off-target effects"—stray mutations—that occasionally appear in gene-edited organisms.) If no red flags appeared, the crop would be approved; otherwise, it would be subject to further review, and possible regulation.
The plan was unveiled in January 2017, during the last week of the Obama presidency. Then, under the Trump administration, it was shelved. Although the USDA continues to promise a new set of regulations, the only hint of what they might contain has been Secretary of Agriculture Sonny Perdue's statement last March that gene-edited plants would remain unregulated if they "could otherwise have been developed through traditional breeding techniques, as long as they are not plant pests or developed using plant pests."
Because transgenic plants could not be "developed through traditional breeding techniques," this statement could be taken to mean that gene editing in which foreign DNA is introduced might actually be regulated. But because the USDA regulates conventional transgenic GMOs only if they trigger the plant-pest stipulation, experts assume gene-edited crops will face similarly limited oversight.
Meanwhile, companies are already teeing up gene-edited products for the U.S. market. An herbicide-resistant oilseed rape, developed using a proprietary technique, has been available since 2016. A cooking oil made from TALEN-tweaked soybeans, designed to have a healthier fatty-acid profile, is slated for release within the next few months. A CRISPR-edited "waxy" corn, designed with a starch profile ideal for processed foods, should be ready by 2021.
In all likelihood, none of these products will have to be tested for safety.
In the E.U., Stricter Rules Apply
Now let's look at the European Union. Since the late 1990s, explains Gregory Jaffe, director of the Project on Biotechnology at the Center for Science in the Public Interest, the EU has had a "process-based trigger" for genetically engineered products: "If you use recombinant DNA, you are going to be regulated." All foods and animal feeds must be approved and labeled if they consist of or contain more than 0.9 percent GM ingredients. (In the U.S., "disclosure" of GM ingredients is mandatory, if someone asks, but labeling is not required.) The only GM crop that can be commercially grown in EU member nations is a type of insect-resistant corn, though some countries allow imports.
European scientists helped develop gene editing, and they—along with the continent's biotech entrepreneurs—have been busy developing applications for crops. But European farmers seem more divided over the technology than their American counterparts. The main French agricultural trades union, for example, supports research into non-transgenic gene editing and its exemption from GMO regulation. But it was the country's small-farmers' union, the Confédération Paysanne, along with several allied groups, that in 2015 submitted a complaint to the ECJ, asking that all plants produced via mutagenesis—including gene-editing—be regulated as GMOs.
At this point, it should be mentioned that in the past 30 years, large population studies have found no sign that consuming GM foods is harmful to human health. GMO critics can, however, point to evidence that herbicide-resistant crops have encouraged overuse of herbicides, giving rise to poison-proof "superweeds," polluting the environment with suspected carcinogens, and inadvertently killing beneficial plants. Those allegations were key to the French plaintiffs' argument that gene-edited crops might similarly do unexpected harm. (Disclosure: Leapsmag's parent company, Bayer, recently acquired Monsanto, a maker of herbicides and herbicide-resistant seeds. Also, Leaps by Bayer, an innovation initiative of Bayer and Leapsmag's direct founder, has funded a biotech startup called JoynBio that aims to reduce the amount of nitrogen fertilizer required to grow crops.)
The ruling was "scientifically nonsensical. It's because of things like this that I'll never go back to Europe."
In the end, the EU court found in the Confédération's favor on gene editing—though the court maintained the regulatory exemption for mutagenesis induced by chemicals or radiation, citing the 'long safety record' of those methods.
The ruling was "scientifically nonsensical," fumes Rodolphe Barrangou, a French food scientist who pioneered CRISPR while working for DuPont in Wisconsin and is now a professor at NC State. "It's because of things like this that I'll never go back to Europe."
Nonetheless, the decision was consistent with longstanding EU policy on crops made with recombinant DNA. Given the difficulty and expense of getting such products through the continent's regulatory system, many other European researchers may wind up following Barrangou to America.
Getting to the Root of the Cultural Divide
What explains the divergence between the American and European approaches to GMOs—and, by extension, gene-edited crops? In part, Jennifer Kuzma speculates, it's that Europeans have a different attitude toward eating. "They're generally more tied to where their food comes from, where it's produced," she notes. They may also share a mistrust of government assurances on food safety, borne of the region's Mad Cow scandals of the 1980s and '90s. In Catholic countries, consumers may have misgivings about tinkering with the machinery of life.
But the principal factor, Kuzma argues, is that European and American agriculture are structured differently. "GM's benefits have mostly been designed for large-scale industrial farming and commodity crops," she says. That kind of farming is dominant in the U.S., but not in Europe, leading to a different balance of political power. In the EU, there was less pressure on decisionmakers to approve GMOs or exempt gene-edited crops from regulation—and more pressure to adopt a GM-resistant stance.
Such dynamics may be operating in other regions as well. In China, for example, the government has long encouraged research in GMOs; a state-owned company recently acquired Syngenta, a Swiss-based multinational corporation that is a leading developer of GM and gene-edited crops. GM animal feed and cooking oil can be freely imported. Yet commercial cultivation of most GM plants remains forbidden, out of deference to popular suspicions of genetically altered food. "As a new item, society has debates and doubts on GMO techniques, which is normal," President Xi Jinping remarked in 2014. "We must be bold in studying it, [but] be cautious promoting it."
The proper balance between boldness and caution is still being worked out all over the world. Europe's process-based approach may prevent researchers from developing crops that, with a single DNA snip, could rescue millions from starvation. EU regulations will also make it harder for small entrepreneurs to challenge Big Ag with a technology that, as Barrangou puts it, "can be used affordably, quickly, scalably, by anyone, without even a graduate degree in genetics." America's product-based approach, conversely, may let crops with hidden genetic dangers escape detection. And by refusing to investigate such risks, regulators may wind up exacerbating consumers' doubts about GM and gene-edited products, rather than allaying them.
"Science...can't tell you what to regulate. That's a values-based decision."
Perhaps the solution lies in combining both approaches, and adding some flexibility and nuance to the mix. "I don't believe in regulation by the product or the process," says CSPI's Jaffe. "I think you need both." Deleting a DNA base pair to silence a gene, for example, might be less risky than inserting a foreign gene into a plant—unless the deletion enables the production of an allergen, and the transgene comes from spinach.
Kuzma calls for the creation of "cooperative governance networks" to oversee crop genome editing, similar to bodies that already help develop and enforce industry standards in fisheries, electronics, industrial cleaning products, and (not incidentally) organic agriculture. Such a network could include farmers, scientists, advocacy groups, private companies, and governmental agencies. "Safety isn't an all-or-nothing concept," Kuzma says. "Science can tell you what some of the issues are in terms of risk and benefit, but it can't tell you what to regulate. That's a values-based decision."
By drawing together a wide range of stakeholders to make such decisions, she adds, "we're more likely to anticipate future consequences, and to develop a robust approach—one that not only seems more legitimate to people, but is actually just plain old better."
Bacterial antibiotic resistance has been a concern in the medical field for several years. Now a new, similar threat is arising: drug-resistant fungal infections. The Centers for Disease Control and Prevention considers antifungal and antimicrobial resistance to be among the world’s greatest public health challenges.
One particular type of fungal infection caused by Candida auris is escalating rapidly throughout the world. And to make matters worse, C. auris is becoming increasingly resistant to current antifungal medications, which means that if you develop a C. auris infection, the drugs your doctor prescribes may not work. “We’re effectively out of medicines,” says Thomas Walsh, founding director of the Center for Innovative Therapeutics and Diagnostics, a translational research center dedicated to solving the antimicrobial resistance problem. Walsh spoke about the challenges at a Demy-Colton Virtual Salon, one in a series of interactive discussions among life science thought leaders.
Although C. auris typically doesn’t sicken healthy people, it afflicts immunocompromised hospital patients and may cause severe infections that can lead to sepsis, a life-threatening condition in which the overwhelmed immune system begins to attack the body’s own organs. Between 30 and 60 percent of patients who contract a C. auris infection die from it, according to the CDC. People who are undergoing stem cell transplants, have catheters or have taken antifungal or antibiotic medicines are at highest risk. “We’re coming to a perfect storm of increasing resistance rates, increasing numbers of immunosuppressed patients worldwide and a bug that is adapting to higher temperatures as the climate changes,” says Prabhavathi Fernandes, chair of the National BioDefense Science Board.
Most Candida species aren’t well-adapted to our body temperatures so they aren’t a threat. C. auris, however, thrives at human body temperatures.
Although medical professionals aren’t concerned at this point about C. auris evolving to affect healthy people, they worry that its presence in hospitals can turn routine surgeries into life-threatening calamities. “It’s coming,” says Fernandes. “It’s just a matter of time.”
An emerging global threat
“Fungi are found in the environment,” explains Fernandes, so Candida spores can easily wind up on people’s skin. In hospitals, they can be transferred from contact with healthcare workers or contaminated surfaces. Most Candida species aren’t well-adapted to our body temperatures so they aren’t a threat. C. auris, however, thrives at human body temperatures. It can enter the body during medical treatments that break the skin—and cause an infection. Overall, fungal infections cost some $48 billion in the U.S. each year. And infection rates are increasing because, in an ironic twist, advanced medical therapies are enabling severely ill patients to live longer and, therefore, be exposed to this pathogen.
The first-ever case of a C. auris infection was reported in Japan in 2009, although an analysis of Candida samples dated the earliest strain to a 1996 sample from South Korea. Since then, five separate varieties – called clades, which are similar to strains among bacteria – developed independently in different geographies: South Asia, East Asia, South Africa, South America and, recently, Iran. So far, C. auris infections have been reported in 35 countries.
In the U.S., the first infection was reported in 2016, and the CDC started tracking it nationally two years later. During that time, 5,654 cases have been reported to the CDC, which only tracks U.S. data.
What’s more notable than the number of cases is their rate of increase. In 2016, new cases increased by 175 percent and, on average, they have approximately doubled every year. From 2016 through 2022, the number of infections jumped from 63 to 2,377, a roughly 37-fold increase.
“This reminds me of what we saw with epidemics from 2013 through 2020… with Ebola, Zika and the COVID-19 pandemic,” says Robin Robinson, CEO of Spriovas and founding director of the Biomedical Advanced Research and Development Authority (BARDA), which is part of the U.S. Department of Health and Human Services. These epidemics started with a hockey stick trajectory, Robinson says—a gradual growth leading to a sharp spike, just like the shape of a hockey stick.
Another challenge is that right now medics don’t have rapid diagnostic tests for fungal infections. Currently, patients are often misdiagnosed because C. auris resembles several other easily treated fungi. Or they are diagnosed long after the infection begins and is harder to treat.
The problem is that existing diagnostics tests can only identify C. auris once it reaches the bloodstream. Yet, because this pathogen infects bodily tissues first, it should be possible to catch it much earlier before it becomes life-threatening. “We have to diagnose it before it reaches the bloodstream,” Walsh says.
The most alarming fact is that some Candida infections no longer respond to standard therapeutics.
“We need to focus on rapid diagnostic tests that do not rely on a positive blood culture,” says John Sperzel, president and CEO of T2 Biosystems, a company specializing in diagnostics solutions. Blood cultures typically take two to three days for the concentration of Candida to become large enough to detect. The company’s novel test detects about 90 percent of Candida species within three to five hours—thanks to its ability to spot minute quantities of the pathogen in blood samples instead of waiting for them to incubate and proliferate.
Unlike other Candida species C. auris thrives at human body temperatures
Adobe Stock
Tackling the resistance challenge
The most alarming fact is that some Candida infections no longer respond to standard therapeutics. The number of cases that stopped responding to echinocandin, the first-line therapy for most Candida infections, tripled in 2020, according to a study by the CDC.
Now, each of the first four clades shows varying levels of resistance to all three commonly prescribed classes of antifungal medications, such as azoles, echinocandins, and polyenes. For example, 97 percent of infections from C. auris Clade I are resistant to fluconazole, 54 percent to voriconazole and 30 percent of amphotericin. Nearly half are resistant to multiple antifungal drugs. Even with Clade II fungi, which has the least resistance of all the clades, 11 to 14 percent have become resistant to fluconazole.
Anti-fungal therapies typically target specific chemical compounds present on fungi’s cell membranes, but not on human cells—otherwise the medicine would cause damage to our own tissues. Fluconazole and other azole antifungals target a compound called ergosterol, preventing the fungal cells from replicating. Over the years, however, C. auris evolved to resist it, so existing fungal medications don’t work as well anymore.
A newer class of drugs called echinocandins targets a different part of the fungal cell. “The echinocandins – like caspofungin – inhibit (a part of the fungi) involved in making glucan, which is an essential component of the fungal cell wall and is not found in human cells,” Fernandes says. New antifungal treatments are needed, she adds, but there are only a few magic bullets that will hit just the fungus and not the human cells.
Research to fight infections also has been challenged by a lack of government support. That is changing now that BARDA is requesting proposals to develop novel antifungals. “The scope includes C. auris, as well as antifungals following a radiological/nuclear emergency, says BARDA spokesperson Elleen Kane.
The remaining challenge is the number of patients available to participate in clinical trials. Large numbers are needed, but the available patients are quite sick and often die before trials can be completed. Consequently, few biopharmaceutical companies are developing new treatments for C. auris.
ClinicalTrials.gov reports only two drugs in development for invasive C. auris infections—those than can spread throughout the body rather than localize in one particular area, like throat or vaginal infections: ibrexafungerp by Scynexis, Inc., fosmanogepix, by Pfizer.
Scynexis’ ibrexafungerp appears active against C. auris and other emerging, drug-resistant pathogens. The FDA recently approved it as a therapy for vaginal yeast infections and it is undergoing Phase III clinical trials against invasive candidiasis in an attempt to keep the infection from spreading.
“Ibreafungerp is structurally different from other echinocandins,” Fernandes says, because it targets a different part of the fungus. “We’re lucky it has activity against C. auris.”
Pfizer’s fosmanogepix is in Phase II clinical trials for patients with invasive fungal infections caused by multiple Candida species. Results are showing significantly better survival rates for people taking fosmanogepix.
Although C. auris does pose a serious threat to healthcare worldwide, scientists try to stay optimistic—because they recognized the problem early enough, they might have solutions in place before the perfect storm hits. “There is a bit of hope,” says Robinson. “BARDA has finally been able to fund the development of new antifungal agents and, hopefully, this year we can get several new classes of antifungals into development.”
New elevators could lift up our access to space
Story by Big Think
When people first started exploring space in the 1960s, it cost upwards of $80,000 (adjusted for inflation) to put a single pound of payload into low-Earth orbit.
A major reason for this high cost was the need to build a new, expensive rocket for every launch. That really started to change when SpaceX began making cheap, reusable rockets, and today, the company is ferrying customer payloads to LEO at a price of just $1,300 per pound.
This is making space accessible to scientists, startups, and tourists who never could have afforded it previously, but the cheapest way to reach orbit might not be a rocket at all — it could be an elevator.
The space elevator
The seeds for a space elevator were first planted by Russian scientist Konstantin Tsiolkovsky in 1895, who, after visiting the 1,000-foot (305 m) Eiffel Tower, published a paper theorizing about the construction of a structure 22,000 miles (35,400 km) high.
This would provide access to geostationary orbit, an altitude where objects appear to remain fixed above Earth’s surface, but Tsiolkovsky conceded that no material could support the weight of such a tower.
We could then send electrically powered “climber” vehicles up and down the tether to deliver payloads to any Earth orbit.
In 1959, soon after Sputnik, Russian engineer Yuri N. Artsutanov proposed a way around this issue: instead of building a space elevator from the ground up, start at the top. More specifically, he suggested placing a satellite in geostationary orbit and dropping a tether from it down to Earth’s equator. As the tether descended, the satellite would ascend. Once attached to Earth’s surface, the tether would be kept taut, thanks to a combination of gravitational and centrifugal forces.
We could then send electrically powered “climber” vehicles up and down the tether to deliver payloads to any Earth orbit. According to physicist Bradley Edwards, who researched the concept for NASA about 20 years ago, it’d cost $10 billion and take 15 years to build a space elevator, but once operational, the cost of sending a payload to any Earth orbit could be as low as $100 per pound.
“Once you reduce the cost to almost a Fed-Ex kind of level, it opens the doors to lots of people, lots of countries, and lots of companies to get involved in space,” Edwards told Space.com in 2005.
In addition to the economic advantages, a space elevator would also be cleaner than using rockets — there’d be no burning of fuel, no harmful greenhouse emissions — and the new transport system wouldn’t contribute to the problem of space junk to the same degree that expendable rockets do.
So, why don’t we have one yet?
Tether troubles
Edwards wrote in his report for NASA that all of the technology needed to build a space elevator already existed except the material needed to build the tether, which needs to be light but also strong enough to withstand all the huge forces acting upon it.
The good news, according to the report, was that the perfect material — ultra-strong, ultra-tiny “nanotubes” of carbon — would be available in just two years.
“[S]teel is not strong enough, neither is Kevlar, carbon fiber, spider silk, or any other material other than carbon nanotubes,” wrote Edwards. “Fortunately for us, carbon nanotube research is extremely hot right now, and it is progressing quickly to commercial production.”Unfortunately, he misjudged how hard it would be to synthesize carbon nanotubes — to date, no one has been able to grow one longer than 21 inches (53 cm).
Further research into the material revealed that it tends to fray under extreme stress, too, meaning even if we could manufacture carbon nanotubes at the lengths needed, they’d be at risk of snapping, not only destroying the space elevator, but threatening lives on Earth.
Looking ahead
Carbon nanotubes might have been the early frontrunner as the tether material for space elevators, but there are other options, including graphene, an essentially two-dimensional form of carbon that is already easier to scale up than nanotubes (though still not easy).
Contrary to Edwards’ report, Johns Hopkins University researchers Sean Sun and Dan Popescu say Kevlar fibers could work — we would just need to constantly repair the tether, the same way the human body constantly repairs its tendons.
“Using sensors and artificially intelligent software, it would be possible to model the whole tether mathematically so as to predict when, where, and how the fibers would break,” the researchers wrote in Aeon in 2018.
“When they did, speedy robotic climbers patrolling up and down the tether would replace them, adjusting the rate of maintenance and repair as needed — mimicking the sensitivity of biological processes,” they continued.Astronomers from the University of Cambridge and Columbia University also think Kevlar could work for a space elevator — if we built it from the moon, rather than Earth.
They call their concept the Spaceline, and the idea is that a tether attached to the moon’s surface could extend toward Earth’s geostationary orbit, held taut by the pull of our planet’s gravity. We could then use rockets to deliver payloads — and potentially people — to solar-powered climber robots positioned at the end of this 200,000+ mile long tether. The bots could then travel up the line to the moon’s surface.
This wouldn’t eliminate the need for rockets to get into Earth’s orbit, but it would be a cheaper way to get to the moon. The forces acting on a lunar space elevator wouldn’t be as strong as one extending from Earth’s surface, either, according to the researchers, opening up more options for tether materials.
“[T]he necessary strength of the material is much lower than an Earth-based elevator — and thus it could be built from fibers that are already mass-produced … and relatively affordable,” they wrote in a paper shared on the preprint server arXiv.
After riding up the Earth-based space elevator, a capsule would fly to a space station attached to the tether of the moon-based one.
Electrically powered climber capsules could go up down the tether to deliver payloads to any Earth orbit.
Adobe Stock
Some Chinese researchers, meanwhile, aren’t giving up on the idea of using carbon nanotubes for a space elevator — in 2018, a team from Tsinghua University revealed that they’d developed nanotubes that they say are strong enough for a tether.
The researchers are still working on the issue of scaling up production, but in 2021, state-owned news outlet Xinhua released a video depicting an in-development concept, called “Sky Ladder,” that would consist of space elevators above Earth and the moon.
After riding up the Earth-based space elevator, a capsule would fly to a space station attached to the tether of the moon-based one. If the project could be pulled off — a huge if — China predicts Sky Ladder could cut the cost of sending people and goods to the moon by 96 percent.
The bottom line
In the 120 years since Tsiolkovsky looked at the Eiffel Tower and thought way bigger, tremendous progress has been made developing materials with the properties needed for a space elevator. At this point, it seems likely we could one day have a material that can be manufactured at the scale needed for a tether — but by the time that happens, the need for a space elevator may have evaporated.
Several aerospace companies are making progress with their own reusable rockets, and as those join the market with SpaceX, competition could cause launch prices to fall further.
California startup SpinLaunch, meanwhile, is developing a massive centrifuge to fling payloads into space, where much smaller rockets can propel them into orbit. If the company succeeds (another one of those big ifs), it says the system would slash the amount of fuel needed to reach orbit by 70 percent.
Even if SpinLaunch doesn’t get off the ground, several groups are developing environmentally friendly rocket fuels that produce far fewer (or no) harmful emissions. More work is needed to efficiently scale up their production, but overcoming that hurdle will likely be far easier than building a 22,000-mile (35,400-km) elevator to space.