Why Space Solar Might Finally Work (But Not How You Think)

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Thanks to reusable rockets that fly, land, and fly again, launch costs are coming back down to Earth. And that’s revived a ‘70s dream to beam clean solar energy from orbit.

Space agencies around the world are revamping blueprints for giant solar farms capturing sunlight 24/7 and wirelessly beaming it down. However, with solar power dirt cheap here on Earth, and space-beaming tech still unproven, I’ve always thought the idea was… a little out there. That is, until a start-up announced plans to scale down both the tech and the price tag.

Backed by the U.S. government, Aetherflux is ditching massive solar farms for single satellites closer to Earth. They plan to use high-powered lasers to beam energy to small, mobile receivers. If this tech reaches lift-off, it could one day deliver power where infrastructure doesn’t exist … from disaster zones to military bases.

With energy costs measured in not just dollars but lives … could this be the special use case that finally launches space-based solar power? And if Aetherflux’s approach works, could it eventually make orbital energy cheap enough for the rest of us? Or is power-beaming still a moonshot?

It’s always sunny in space.¹ There are no clouds, pollution, dust, weather, or even an atmosphere to dim the sunlight.² And for most of the year, the sun would never set on a solar farm parked high above the equator in geostationary orbit (or GEO).³

The potential is astronomical. In 2007, the U.S. Department of Defense’s National Security Space Office reported a shocking estimate: One year of sunlight from a single 1 km band (about 3/5ths of a mile) in space equals the energy in every oil field on Earth. ⁴⁵

So, how do you pull that off? The concept is sci-fi simple. Just ship solar panels into space, let robots snap them together, collect that energy into a giant microwave transmitter, and aim it at a receiving station on Earth.⁶⁷ No sweat, right?

Robots aside, these proposed megastructures would dwarf the biggest space structure ever built: the International Space Station, which measures 109 m (or about 360 ft).⁸³ This solar power satellite would have to be kilometers wide⁷ and assembled from materials launched over hundreds of rocket flights.⁷ The ground receiving station would also span a kilometer of antennas that convert microwaves back into electricity.⁷³

In theory, microwaves work great for power beaming because clouds, fog, and even rain barely block them.⁹¹⁰ But here’s the catch: to steer a microwave beam from a kilometer-wide phased array onto a receiver on Earth, a million tiny antennas all have to fire in perfect sync, with timing accuracy down to just a few picoseconds.³¹¹ That’s not just hard. That’s engineering hard.

Challenges like these have kept space-based solar power grounded for decades. But a start-up called Aetherflux thinks it’s found a way around them.

Gathering Aetherflux

Founder Baiju Bhatt of Robinhood fame wants to lower the bar (and the orbit) of space-based solar. Aetherflux’s strategy is to take a modular approach in low earth orbit (LEO).⁶ It’s a page out of Starlink’s playbook: launch a swarm of small satellites in LEO to cover limited areas, handing off from one satellite to another as they orbit the planet.¹²¹³¹⁴

For space-based solar, flying low comes with a built-in disadvantage: Earth will cast a shadow over the satellite’s solar panels some of the time. A satellite at 550 km (or about 342 miles) up completes one orbit every 96 minutes, spending 35 minutes in darkness.¹⁵ That’s why Aetherflux plans to launch not just solar arrays, but battery packs, too, to keep beaming power during the eclipse.¹⁴

So… why on Earth would you stick satellites where the sun don’t shine?

Because it lets them ditch that hard engineering problem; instead of microwaves, Aetherflux is betting on laser power transmission.¹⁶ The company claims that at this lower altitude, a high-precision near-infrared laser can deliver power to a spot just 10 m wide, which is about the size of six parking spaces.

Based on what Aetherflux has disclosed and typical laser setups, the system likely works like this: sunlight hits the panels, gets converted into electricity, powers laser diodes, and that light travels through a fiber to an optical system that focuses the beam toward a receiver on Earth.^17161819

That’s triple conversion. Each step loses energy, and that’s before factoring in losses from charging and discharging battery packs. Reception is another challenge. Microwave beams cut through bad weather, but atmospheric conditions can scatter laser beams, cutting efficiency down further.

Dollar for dollar, watt for watt, how could a system with this many losses compete with dirt-cheap ground solar?

Well, maybe, when there’s no land for a solar farm. Say … on the battlefield.

Precision Power Delivery for Forward Military Bases

Bhatt believes Aetherflux’s receivers could eventually shrink to just five meters wide or the size of two parking spots.¹⁶ That kind of precision power delivery has made the military stand at attention.

That’s because getting fuel into conflict zones isn’t just expensive. It’s dangerous. Aetherflux’s website emphasizes that attacks on fuel convoys caused nearly half of American deaths in Iraq and almost 40% in Afghanistan according to a report by Deloitte Consulting.²⁰

Power-on-demand from space could be a game-changer for forward military bases.²¹ If the tech works (and the price is right), the Department of Defense could become Aetherflux’s first customer.

In February 2025, the DoD’s Operational Energy Capability Improvement Fund announced plans to help bankroll Aetherflux’s 2026 proof of concept demonstration.²² If the demo works, Aetherflux’s tech could do more than power the battlefield. It could keep disaster relief zones online, speed up rebuilding after crises, connect remote communities, and even keep mines operating where the grid doesn’t reach.²³²¹

So, how close are we to actually seeing this thing fly?

T minus …?

Aetherflux is a young company; it only announced its plans in late 2024.⁶ Its team is testing scaled-down versions of the tech they’ll need for a planned demo in 2026, where they hope to beam up to 4 kW of peak power from a satellite 550 km up. That’s roughly enough to run four microwave ovens at full blast.²⁴²⁵

To move this quickly, Aetherflux plans to use as many off-the-shelf parts as possible. The space industry has matured incredibly this past decade, so plenty of standardized components are now available.¹⁷ The satellite payload will ride on a stock chassis from Apex Space, which can be ordered with large solar arrays that track the sun.²⁶²⁴¹⁷ High-powered near-infrared lasers up to 10 kW are also ripe for the picking.²⁷¹⁷

Space-grade solar panels are already established tech. These multi-junction gallium arsenide solar cells are designed to survive harsh radiation and convert about 30% of incoming sunlight into electricity, compared to around 20% for standard silicon panels on Earth.²⁸²⁹ However, according to the National Renewable Energy Laboratory, these space-rated cells are still 100 to 200 times more expensive per watt than terrestrial panels.³⁰

Launch is also “off the shelf” nowadays, as Bhatt told Arkaea Media Group:¹⁷

With the development of reusable rockets, launch costs have come crashing down…safely this time. In August 2025, a SpaceX Falcon 9 booster notched its 30th successful flight and landing.³¹ SpaceX charges about $2,600 per kilogram, or $1,180 per pound. That’s just 5% of launch costs on the Space Shuttle. Once SpaceX’s larger Starship rocket is fully up and running, prices are expected to drop even more.⁷

Aetherflux isn’t the only one betting on cheaper launches and faster hardware development; space agencies pursuing giant, GEO-based solar farms would benefit, too. So why isn’t Bhatt chasing a larger-scale design?

As he told Space News,

“That design is not one that you can iterate on. It’s all or nothing.”¹⁴

“The approach of power transmission that we’re taking, which is infrared laser based, is something that you can actually make on an arbitrarily small spacecraft.”¹⁴

Why do GEO microwave solar farms have to be so gigantic? These kilometer-scale satellites delivering gigawatts of power are massive because of the physics of beaming energy through space. It’s about how microwaves spread out as they travel tens of thousands of kilometers… and why that would force us to build such massive structures in orbit.

In the extended cut on Patreon, I break down the surprising physics behind it and explain why switching from microwaves to lasers could shrink everything dramatically.

Step backwards from a wall with a flashlight and you’ll see the circle of light grow bigger and dimmer. That’s because waves naturally spread out in a cone, and the farther they travel, the wider the beam becomes. For space-based solar power, that’s a big deal. The wider the beam, the bigger the receiver you need on the ground.

One way to shrink the receiver is simple: bring the satellite closer. Drop from GEO at 35,786 km down to LEO around 550 km, and the beam doesn’t have as much room to spread. The tradeoff is that GEO offers nearly 24/7 sunlight. As you can imagine, that’s a huge advantage for power generation, which is exactly why traditional designs stick with it.

Another way to fight beam spread is to make the transmitter bigger. Swap out the dinky flashlight for a massive searchlight, and you’ll notice how tightly that beam holds together, even as it travels a long distance into the air. It’s the same in space: to beam microwaves from 36,000 km, engineers scale up the transmitter aperture to a full kilometer across, roughly 3/5ths of a mile. Even then, the receiver still has to span 10 km, or more than six miles. Ouch.

There’s a third trick: shorten the wavelength. Traditional microwave plans use 2.45 GHz microwaves, which have a wavelength of about 12 cm. Aetherflux, on the other hand, plans to use near-infrared lasers with wavelengths around 1 micron, which is about 100,000 times shorter.

Here’s why that matters: if Aetherflux wants to hit a 10-meter-wide receiver from 550 km up, the required transmitter aperture comes out to about 13 centimeters. That’s just over five inches, compared to the 10 kilometers you’d need for microwaves.

By switching to lasers and flying lower, Aetherflux shrinks the transmitter from miles wide to something you could hold in your hand.

Another complication is that light refracts as it passes through different mediums. If you’ve ever looked at a fish in a pond, its image is in a slightly different spot than the fish. It’s why a stick looks bent when you stick it in the water, too. The same is true with light passing through the vacuum of space, then into an increasingly denser atmosphere as you approach the surface of the Earth. While the effect is not as severe as the air to water transition, it is a measurable effect.

However, even with smaller systems and standardized parts, Aetherflux still faces some tough engineering problems it’ll have to solve on its own.

Houston, We Have A Solution?

Bhatt says the company is building its own optical, power transmission, and reception systems,¹⁷ components tailored for laser power beaming, and a telescope. Swapping microwaves for lasers won’t be as easy as just shrinking scales, though. Henri Barde, a former senior power-systems specialist at the European Space Agency and a long-time skeptic of space-based solar power, points out that laser-based systems just face different design challenges than microwave ones.¹⁹

He estimates that in low Earth orbit, each satellite might only have about a 10-minute window to beam power to a ground receiver before dropping below the horizon. That means a constellation of satellites would be needed to keep power flowing. Aetherflux plans for about 100 satellites to provide “seamless energy delivery,” each carrying battery banks to keep beaming power whenever Earth blocks the sun.³²

Barde warns that laser power beaming is inefficient. Lasers lose about half the energy put into them as heat, and infrared receivers on the ground will capture less than half of what’s transmitted.³³¹⁷¹⁹ That means for every kilowatt delivered to the ground, the satellite would need to push about five kilowatts into the laser. To make that possible, Barde says, the satellites would need large onboard batteries, ballooning both the weight and the budget of the constellation.¹⁹.

Microwave systems don’t face the same penalty: transmission and reception each hit around 80% efficiency.³³ And while microwaves cut through bad weather, laser light is scattered by atmosphere, clouds, and dust. These efficiency losses don’t add up … they multiply.

That said, as much as efficiency matters, cost matters more. With the Department of Defense funding projects like Aetherflux, it’s clear they’re interested in pushing laser power-beaming forward. In May 2025, DoD researchers set a record of their own, transmitting 800 watts over 8 km on Earth — a step toward proving that power beaming can go the distance.³⁵

Accurately aiming that laser beam is going to be an engineering feat, according to Barde. He says that a laser pointed from over 500 km up toward a receiver the size Aetherflux is proposing would need to dynamically point with an accuracy of about one microradian.¹⁹ That’s less than one ten-thousandth of a degree.

That level of precision has been demonstrated both in satellite-to-satellite laser communications and military laser systems that can lock onto small, fast-moving targets kilometers away.³⁶³⁷ Aetherflux’s challenge is combining those capabilities: making something as lightweight as what’s flown in space but as powerful as the lasers mounted on ships and large aircraft.

With all this talk of military lasers, you’re probably wondering…

Is This Dangerous?

Safety-wise, microwaves have the edge. Radiation at the receiver is just a quarter the intensity of sunlight. Lasers are trickier since they’re invisible but can blind or burn at high power.³⁸¹³⁹ I’m sure I wasn’t the only kid told not to shine one in someone’s eye, and for good reason. Even a brief misfire could be dangerous.⁴⁰

To reduce risks, Aetherflux plans a “lock-on” safety system: the satellite pings the receiver before firing, and the beam automatically shuts off if it’s interrupted … whether by a bird, a plane, or a bad aim.¹⁷

They’ll also need serious cybersecurity. Space consulting agency Frazer-Nash warns that space-based solar power systems (microwave or laser) will need strong defenses against hacks and safety systems built right into the hardware.⁴¹ That means failsafes like the one Aetherflux plans, along with hardware-level power caps.³⁸

The dangers aren’t limited to Earth. Space may seem spacious, but it’s getting crowded fast. By 2030, there could be nearly 60,000 active satellites in orbit,⁴² driven mostly by megaconstellations like Starlink, Amazon’s Project Kuiper, and China’s Guowang network. All competing for global broadband coverage.¹³⁴³⁴⁴

These satellites are sharing orbit with a growing field of debris. Right now, there are nearly 37,000 tracked fragments larger than 10 cm, or 4 in. Then there’s over a million smaller fragments that are too tiny to track, but still dangerous.⁴² Satellites in low Earth orbit whip around the planet at more than 28,000 km/h (17,500 mph).⁴⁵ At those speeds, even a paint-chip-sized piece of debris can punch through a solar panel, knock out a sensor or reflect a laser beam away from its target.

The more hardware we launch, the higher the risk of collisions — and the dreaded Kessler effect, where one crash triggers a chain reaction of debris that could make entire orbits unusable.⁴² Basically the movie “Gravity,” except this time it’s not special effects. To get ahead of the problem, the European Space Agency is planning its first active debris cleanup and now recommends satellites de-orbit within five years of retirement instead of 25.⁴⁶

De-orbiting isn’t a clean escape. Most satellites burn up on re-entry, and their aluminum frames release aluminum oxide particles that can linger in the atmosphere for decades and damage the ozone layer.⁴⁷⁴² And all those valuable solar panels and battery metals? Vaporized, instead of recycled on Earth.

Long Shot? Or Long Game?

Despite the drawbacks, price has always been the make-or-break for space-based solar power. NASA first explored the concept during the 1970s fuel crisis, planning a giant solar farm in GEO. But the numbers came back: $1 trillion in today’s dollars and a timeline measured in decades. The idea was shelved.⁷³

Today, advances in robotics, composite materials, and launch capabilities have brought the concept back into play. Around the world, space agencies are revisiting the idea of gigawatt-scale, GEO-based, microwave-transmitting solar power stations.

The numbers are getting compelling. In August 2025, King’s College London found space solar could replace 80% of Europe’s renewables and cut energy costs 15%.⁴⁸ Recent analysis by Frazer-Nash Consultancy and London Economics shows space solar at $76 per MWh. That’s competitive once you factor in battery storage costs for ground-based systems at around $120 per MWh.⁴⁹

The race is global now. Europe’s SOLARIS program faces a go/no-go decision in 2025.⁵⁰ The U.K.’s planning a 30 MW demo by 2030,⁵¹ Japan is launching a 1kW demo in 2025,⁴⁹⁵² and China is targeting a 10 MW pilot plant in orbit by 2035.⁴⁹ It’s a big gamble, but one that’s finally getting serious money.

Aetherflux? Unlike these megaprojects, Aetherflux isn’t competing with solar farms on Earth. It’s focused on replacing fuel convoys in combat zones, where the cost of delivery is measured not just in dollars but sometimes in lives. Its success hinges on proving it can beam power from low Earth orbit to a receiver the size of a pickleball court at a price point the Department of Defense can keep in play.

The applications don’t stop at the battlefield. If the system works, Aetherflux satellites could sell surplus power as they pass over other parts of the globe. Andrew Yarmola, Aetherflux’s head of engineering, told Freethink:³⁴

“I see our technology providing power during heat waves, frigid winters, and lightening the load on failing electrical infrastructure so it can be repaired before causing catastrophic damage.”

Long term, Aetherflux wants to become a commercially viable provider of clean, affordable power for everyday consumers.³⁴ Whether that happens depends on how cheaply and safely the company can deliver energy from space. That is, if Aetherflux, or any of the other contenders, can launch this 1970s moonshot into a real-world score.