So-Called “Puppy Mills” Are Not All As Bad As We Think, Pioneering Research Suggests
Candace Croney joined the faculty at Purdue University in 2011, thinking her job would focus on the welfare of livestock and poultry in Indiana. With bachelor's, master's, and doctoral degrees in animal sciences, her work until then had centered on sheep, cattle, and pigs. She'd even had the esteemed animal behaviorist Temple Grandin help shape her master's research project.
Croney's research has become the first of its kind in the world—and it's challenging our understanding of how dog breeding is being done.
Then came an email from a new colleague asking Croney to discuss animal welfare with some of Indiana's commercial dog breeders, the kind who produce large quantities of puppies for sale in pet stores.
"I didn't even know the term commercial breeders," Croney says. "I'd heard the term 'puppy millers.' That's pretty much what I knew."
She went to the first few kennels and braced herself for an upsetting experience. She's a dog lover who has fostered shelter mutts and owned one, and she'd seen the stories: large-scale breeders being called cruel and evil, lawmakers trying to ban the sale of commercially bred puppies, and constant encouragement to rescue a dog instead of paying into a greedy, heartless "puppy mill" industry.
But when she got to the kennels, she was surprised. While she encountered a number of things she didn't like about the infrastructure at the older facilities—a lack of ventilation, a lot of noise, bad smells—most of the dogs themselves were clean. The majority didn't have physical problems. No open sores. No battered bodies. Nothing like what she'd seen online.
But still, the way the dogs acted gave her pause.
"Things were, in many regards, better than I thought they would be," Croney says. "Google told me the dogs would be physically a mess, and they weren't, but behaviorally, things were jumping out at me."
While she did note that some of the breeders had play yards for their pups, a number of the dogs feared new people and things like leashes because they hadn't been exposed to enough of them. Some of the dogs also seemed to lack adequate toys, activities, and games to keep them mentally and physically stimulated.
But she was there strictly as a representative of the university to ask questions and offer feedback, no more or less. A few times, she says, she felt like the breeders wanted her to endorse what they were doing, "and I immediately got my back up about that. I did not want my name used to validate things that I could tell I didn't agree with. It was uncomfortable from that perspective."
After sharing the animal-welfare information her colleague had requested, Croney figured that was that. She never expected to be in a commercial kennel again. But six months later, her phone rang. Some of the people she'd met were involved in legislative lobbying, and they were trying to write welfare standards for Indiana's commercial breeders to follow.
In the continuing battle over what is, and is not, a "puppy mill," they wanted somebody with a strong research background to set a baseline standard, somebody who would actually bring objectivity to the breeder-activist conflict without being on one side or the other.
In other words, they wanted Croney's help to figure out not only appropriate enclosure sizes, but also requirements for socialization and enrichment activities—stimulation she knew the dogs desperately needed.
"I thought, crap, how am I not going to help?" she recalls. "And they said, 'Well how long will that take? A couple of weeks? A month?'"
Dr. Croney with Theo, whom she calls "a beloved family member of our research team."
(Photo credit: Purdue University/Vincent Walter)
Six years later, Croney's research remains ongoing. It has become the first of its kind in the world—and it's challenging our understanding of how dog breeding is being done, and how it could and should be done for years to come.
How We Got Here
Americans have been breeding pet dogs in large-scale kennels since World War II. The federal standard that regulates those kennels is the Animal Welfare Act, which President Johnson signed into law in 1966. Back then, people thought it was OK to treat dogs a lot differently than they do today. The law has been updated, but it still allows a dog the size of a Beagle to be kept in a cage the size of a dishwasher all day, every day because for some dogs, when the law was written, having a cage that size meant an improvement in living conditions.
Countless commercial breeders, who are regularly inspected under the Animal Welfare Act, have long believed that as long as they followed the law, they were doing things right. And they've seen sales for their puppies go up and up over the years. About 38 percent of U.S. households now own one or more dogs, the highest rate since the American Veterinary Medical Association began measuring the statistic in 1982.
Consumers now demand eight million dogs per year, which has reinforced breeders' beliefs that despite what activists shout at protests, the breeders are actually running businesses the public supports. As one Ohio commercial breeder—long decried by activists as a "puppy mill" owner—told The Washington Post in 2016, "This is a customer-driven industry. If we weren't satisfying the customer, we'd starve to death. I've never seen prices like the ones we're seeing now, in my whole career."
That breeder, though, is also among leading industry voices who say they understand that public perception of what's acceptable and what's not in a breeding kennel has changed. Regardless of what the laws are, they say, kennels must change along with the public's wishes if the commercial breeding industry is going to survive. The question is how, exactly, to move from the past to the future, at a time when demands for change have reached a fever pitch.
"The Animal Welfare Act, that was gospel. It meant you were taking care of dogs," says Bob Vetere, former head of the American Pet Products Association and now chairman of the Pet Leadership Council. "That was, what, 40 years ago? Things have evolved. People understand much more since then—and back then, there were maybe 20 million dogs in the country. Now, there's 90 million. It's that dramatic. People love their dogs, and everybody is going to get one."
Vetere became an early supporter of Croney's research, which, unbelievably, became the first ever to focus on what it actually means to run a good commercial breeding kennel. At the start of her research, Croney found that the scientific literature underpinning many existing laws and opinions was not just lacking, but outright nonexistent.
"We kept finding it over and over," she says of the literature gaps, citing common but uninformed beliefs about appropriate kennel size as just one example. "I can't find any research about how much space they're supposed to have. People said, 'Yeah, we had a meeting and a bunch of people made some recommendations.'"
She started filling in the research gaps with her team at Purdue, building relationships with dog breeders until she had more than 100 kennels letting her methodically figure out what was actually working for the dogs.
"The measurable successes in animal welfare over the past 50 years began from a foundation in science."
Creating Standards from Scratch
Other industry players soon took notice. One was Ed Sayres, who had served as CEO of the ASPCA for nearly a decade before turning his attention to lobbying efforts regarding the "puppy mill" issue. He recognized that what Croney was doing for commercial breeding mirrored the early work researchers started a half-century ago in the effort that led to better shelters all across America today.
"The measurable successes in animal welfare over the past 50 years began from a foundation in science," Sayres says. "Whether it was the transition to more humane euthanasia methods or how to manage dog and cat overpopulation, we found success from rigorous examination of facts and emerging science."
Sayres, Vetere, and others began pushing for the industry to support Croney's work, moving the goalposts beyond Indiana to the entire United States.
"If you don't have commercial breeding, you have people importing dogs from overseas with no restrictions, or farming in their backyards to make money," Vetere says. "You need commercial breeders with standards—and that's what Candace is trying to create, those standards."
Croney ended up with a $900,000 grant from three industry organizations: the World Pet Association, Pet Food Institute, and the Pet Industry Joint Advisory Council. With their support, she created a nationwide program called Canine Care Certified, like a Good Housekeeping Seal of Approval for a kennel. The program focuses on outcome-based standards, meaning she looks at what the dogs tell her about how well they are doing through their health and behavior. For the most part, beyond baseline requirements, the program lets a breeder achieve those goals in whatever ways work for the dogs.
The approach is different from many legislative efforts, with laws stating a cage must be made three feet larger to be considered humane. Instead, Croney walks through kennels with breeders and points out, for instance, which puppies in a litter seem to be shy or fearful, and then teaches the breeders how to give those puppies better socialization. She helps the breeders find ways to introduce dogs to strangers and objects like umbrellas that may not be part of regular kennel life, but will need to become familiar when the breeding dog retires and gets adopted into a home as a pet. She helps breeders understand that dogs need mental as well as physical stimulation, whether it comes from playing with balls and toys or running up and down slides.
The breeders can't learn fast enough, Croney says, and she remains stunned at how they constantly ask for more information—an attitude that made her stop using the term "puppy mill" to describe them at all.
"Now, full disclosure: Given that all of these kennels had volunteered, the odds were that we were seeing a skewed population, and that it skewed positive," she says. "But if you read what was in the media at the time, we shouldn't have been able to find any. We're told that all these kennels are terrible. Clearly, it was possible to get a positive outcome."
To Buy or Not to Buy?
Today, she says, she's shocked at how quickly some of the kennels have improved. Facilities that appalled her at first sight now have dogs greeting people with wagging tails.
"Not only would I get a dog from them, but would I put my dog there in that kennel temporarily? Yeah, I would."
"The most horrifying thing I learned was that some of these people weren't doing what I'd like to see, not because they didn't care or only wanted money, but because nobody had ever told them," she says. "As it turned out, they didn't know any different, and no one would help them."
For Americans who want to know whether it's OK to get a commercially bred puppy, Croney says she thinks about her own dogs. When she started working with the breeders, there were plenty of kennels that, she says, she would not have wanted to patronize. But now she's changing her mind about more and more of them.
"I'm just speaking as somebody who loves dogs and wants to make sure I'm not subsidizing anything inhumane or cruel," she says. "Not only would I get a dog from them, but would I put my dog there in that kennel temporarily? Yeah, I would."
She says the most important thing is for consumers to find out how a pup was raised, and how the pup's parents were raised. As with most industries, commercial breeders run the gamut, from barely legal to above and beyond.
Not everyone agrees with Croney's take on the situation, or with her approach to improving commercial breeding kennels. In its publication "Puppy Mills and the Animal Welfare Act," the Humane Society of the United States writes that while Croney's Canine Care Certified program supports "common areas of agreement" with animal-welfare lobbyists, her work has been funded by the pet industry—suggesting that it's impure—and a voluntary program is not enough to incentivize breeders to improve.
New laws, the Humane Society states, must be enacted to impose change: "Many commercial dog breeding operators will not raise their standards voluntarily, and even if they were to agree to do so it is not clear whether there would be any independent mechanism for enforcement or transparency for the public's sake. ... The logical conclusion is that improved standards must be codified."
Croney says that type of attitude has long created resentment between breeders and animal-welfare activists, as opposed to actual kennel improvements. Both sides have a point; for years, there have been examples of bottom-of-the-barrel kennels that changed their ways or shut down only after regulators smacked them with violations, or after lawmakers raised operating standards in ways that required improvements for the kennels to remain legally in business.
At the same time, though, powerful organizations including the Humane Society—which had revenue of more than $165 million in 2018 alone—have routinely pushed for bans on stores that sell commercially bred puppies, and have decried "puppy mills" in marketing and fund-raising literature, without offering financial grants or educational programs to kennels that are willing to improve.
Croney believes that the reflexive demonization of all commercial breeders is a mistake. Change is more effective, she says, when breeders "want to do better, want to learn, want to grow, and you treat them as advocates and allies in doing something good for animal welfare, as opposed to treating them like they're your enemies."
"If you're watching undercover videos about people treating animals in bad ways, I'm telling you, change is happening."
She adds that anyone who says all commercial breeders are "puppy mills" needs to take a look at the kennels she's seen and the changes her work has brought—and is continuing to bring.
"The ones we work with are working really, really hard to improve and open their doors so that if somebody wants to get a dog from them, they can be assured that those dogs were treated with a level of care and compassion that wasn't there five or 10 years ago, but that is there now and will be better in a year and will be much better in five years," she says. "If you're watching undercover videos about people treating animals in bad ways, I'm telling you, change is happening. It is so much better than people realize, and it continues to get even better yet."
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.