The groundbreaking experimental aircraft known as Solar Impulse 2 has met an untimely end. According to a National Transportation Safety Board report, the completely solar-powered plane crashed into the Gulf of Mexico during an autonomous test flight on May 4. While there were no injuries or fatalities, the wreck of the Solar Impulse marks an unfortunate end for one of the most impressive and inspirational planes in aviation history.

Solar Impulse was first conceptualized in 2003 by Bertrand Piccard, the grandson of Swiss deep sea pioneer Auguste Piccard and the son of Jacque Piccard, the first person to reach the Mariana Trench. Piccard never intended the vehicle for commercial use, but instead envisioned it as a way to raise awareness for sustainable energy by building the first solar-powered plane capable of circumnavigating the globe. The first iteration, Solar Impulse 1, completed its inaugural test flight in 2009 followed by multiple additional trips over the next few years.

Construction on Solar Impulse 2 began in 2011. Even with a 232-foot wingspan that made it wider than a Boeing 747, the completely carbon-fiber frame ensured the plane only weighed about 5,100 lbs, making it about as heavy as a standard SUV. The 130-cubic-foot, nonpressurized cockpit included oxygen reserves and additional environmental equipment to enable a pilot to travel long distances at a maximum altitude of 39,000 feet. According to sUAS News, a total of 17,248 photovoltaic solar cells offered a peak power output of 66 kW to four electric motors and four lithium-ion batteries weighing nearly 1,400 lbs. Basic autopilot technology also allowed its sole occupant to sleep in 20 minute intervals.

Solar Impulse 2 made history in 2016 as the first fixed-wing, entirely solar-powered plane to circumnavigate the Earth. The feat was accomplished over the course of 16.5 months, with Piccard alternating piloting duties with Foundation co-founder André Borschberg and making 17 stops along the route. Solar Impulse 2 cruised at a ground speed between 31 and 62 mph, relying on the slower pace during evening portions of the trip.

In 2019, the Solar Impulse Foundation announced the sale of Solar Impulse 2 to Skydweller Aero for an undisclosed sum. The Spanish–American company’s plans were very different from the plane’s initial purpose. Instead of focusing on its solar capabilities, Skydweller hoped to pursue its military-related surveillance potentials, which included “carrying radar, electronic optics, telecommunications devices, telephone listening, and interception systems.”

After supplying numerous modifications, Solar Impulse 2 completed its first autonomous flight in Spain in 2023. The first entirely uncrewed, autonomous flight took place at Stennis International Airport near Bay St. Louis, Mississippi, the following year. At the time, Skydweller also confirmed its larger goal was to develop and supply a fleet of uncrewed, solar-powered planes capable of nonstop flight at latitudes between Miami (26°N) to Rio de Janeiro (23°S). These near-continuous operations would involve military and commercial contracts, allegedly at a much lower cost than current satellite options. The overhauled flagship aircraft reportedly crashed after losing power while flying over the Gulf of Mexico on May 4.

“We learned through social media about the crash of the Skydweller solar drone,” Piccard and Borschberg wrote in a statement provided to Popular Science. “The Solar Impulse team is saddened by the loss of an important technological flagship.”

Skydweller representatives did not respond to Popular Science at the time of writing. According to the Swiss news outlet SWI, part of Solar Impulse Foundation’s original sales contract with Skydweller stipulated the aircraft would eventually return to Switzerland for installation in the Swiss Museum of Transport in Lucerne.

“Very often when we speak of protection of the environment, it’s boring,” Piccard told Popular Science in 2013. “The first airplane [had] the technology of 2007. The second airplane [had] the technology of tomorrow.”

The post World’s largest solar-powered aircraft crashes after losing power appeared first on Popular Science.

Wind turbines are a net positive for a sustainable society, but that doesn’t mean they don’t have an environmental impact. Apart from their material requirements, those giant, spinning blades can be lethal to unsuspecting winged animals like birds and bats. Although some reports dramatically overplay wind farms’ danger to flying species, there is no denying they can unintentionally kill anywhere from two-to-six birds and four-to-seven bats per megawatt every year. That may not seem like many fatalities, but every animal counts for an endangered species.

To lower these risks, engineers are devising new ways to make wind turbines more visible and avoidable. One potential solution may involve taking a cue from some of nature’s most dangerous creatures. According to a study published in the journal Behavioral Ecology, more bats and birds will steer clear of wind turbines when their blades are painted with colors similar to animals like venomous coral snakes and poison dart frogs.

“White blades, which are the most frequently used pattern around the world, turned out to be the worst option for birds,” Johanna Mappes, a University of Helsinki environmental scientist and study co-author, said in a statement. “This suggests that a relatively simple visual change could reduce bird mortality in connection with wind power.”

To test how birds respond to various turbine designs, Mappes and her colleagues placed test subjects in front of a video screen in a controlled laboratory environment. They then played clips of wind blades with multiple color palettes spinning at different speeds. These included turbines featuring classic white blades, one blade painted black, blades with red-and-white stripes, or blades with a newly designed, biomimetic red-black-yellow pattern.

“By using a touchscreen especially designed for birds, we can use games to explore their behavior and ecology by simulating real-world scenarios, without putting the birds at risk,” explained University of Exeter ecologist and study co-author George Hancock.

In nearly every trial, the birds were far more likely to approach white blades than any of the colored options. However, the test subjects were the most avoidant of the team’s novel, biomimetic striped blades.

“We’ve known for a long time that birds change how they respond to objects with warning colors, but to see such a large effect was remarkable,” Hancock added.

There is no way to completely prevent wind turbines from ever accidentally harming or killing animals. That said, the study’s authors believe a wider industry adoption of evolutionarily inspired color schemes could be an easy, cheap way to make the technology safer. They also suggest that similar approaches be developed for other human-made avian dangers like power lines and building windows.

“If the results are repeated in practical conditions in different countries and with different bird species, it could be a significant change for the entire wind power industry,” said Mappes.

The post Birds avoid wind turbines painted like venomous snakes appeared first on Popular Science.

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Editor’s Note: This episode originally aired on December 15, 2025.

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Renewable energy is the cornerstone of any sustainable society, but why limit your options to wind or solar installations? In the United States alone, over one million homes host a tiny, furry alternative power source without even realizing it. As a young YouTuber known as Flamethrower recently demonstrated, it’s time for hamsters to start pulling their weight around the house. Or, at the least, it’s time for them to start turning hamster wheels into miniature, makeshift turbines.

The idea came to Flamethrower after his brother received one of the tiny pets for his birthday. Although adorable, naturally nocturnal hamsters are often up at all hours of the night running on their little exercise accessories. While laying awake to the sound of a spinning, squeaky wheel, the amateur engineer realized how to make the best of an unexpectedly annoying situation.

“So what did I do? Exploit it for energy production, of course!” he declared in his recent video entry.

Turbines help generate most of the world’s energy, and their underlying principles are simple enough. Electricity funneled through wires to a motor will make it spin, but the reverse is also true—spin a motor, and electricity will generate through its terminals into battery storage. The fundamentals are basically the same whether a turbine spins thanks to steam, wind, or nuclear power. Or hamsters.

However, a hamster-powered turbine is not the easiest project to design. As the YouTuber explained, a 5 volt (V) DC motor hypothetically needs to spin at over 10,000 RPM to simply reach a smartphone’s standard 15 watt charging speed. Even if such a superpowered hamster existed, its speed would likely cause the motor to melt before it provided any juice to a battery—and therein lay another issue. 

Batteries don’t only store energy—they are designed to provide electricity at a steady current when needed. However, a standard battery also must receive a higher voltage than it stores in order to amass any reserves. 

Part of the solution came from a device known as an energy harvester module, which takes small voltages and amplifies them to an acceptable level for a battery. But the problem is that the amount of required voltage increases in direct proportion to the energy that’s being stored, meaning yet another unfeasible hurdle. The hobbyist ultimately relied on a system called maximum power point tracking (MPPT) to calculate the optimal input and output proportions for the energy harvester and a few other components. 

All that potential energy is only as good as the battery that stores it, however. For this project, the YouTuber relied on lithium-ion cells salvaged from a broken electric scooter. Flamethrower hooked up his rig to the hamster wheel’s axis, then gave his brother’s pet the night to get its steps in. The next day, he attached his phone via a USB cable charging port to test the whole thing for the first time.

The initial setup worked flawlessly, although it charged at a snail’s pace. Naturally, he booted up his thermal camera nearby (who doesn’t own one?) to investigate any pain points in the system. It turns out the issue did have anything to do with the hamster wheel charger itself, but his outdated USB cable. After swapping that out with a newer replacement, phone charging sped up dramatically.

“And with that, my hamster’s life finally has a purpose,” the inventor declared.

As absurd as it appears, it’s hard to argue with such an ingenious source of free electricity. Hypothetically, the same idea could be adapted to basically anything in a house that spins mechanically, like a stationary bike. Then again, the whole point is to have the hamster do the work, not you. In any case, the YouTuber seems to be on to something here. The way Flamethrower tells it, the rodent may be more reliable than solar or wind energy.

“It’s supposed to be nocturnal but I’m starting to think it never sleeps,” he said.

In The Workshop, Popular Science highlights the ingenious, delightful, and often surprising projects people build in their spare time. If you or someone you know is working on a hobbyist project that fits the bill, we’d love to hear about it—fill out this form to tell us more.

The post Clever kid builds phone charger powered by pet hamster appeared first on Popular Science.