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A US startup plans to deliver ‘sunlight on demand’ after dark. Can it work? Would we want it to?

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A US startup plans to deliver ‘sunlight on demand’ after dark. Can it work? Would we want it to?


Credit: Unsplash/CC0 Public Domain

A proposed constellation of satellites has astronomers very worried. Unlike satellites that reflect sunlight and produce light pollution as an unfortunate byproduct, the ones by US startup Reflect Orbital would produce light pollution by design.

The company promises to produce “sunlight on demand” with that beam sunlight down to Earth so solar farms can operate after sunset.

It plans to start with an 18-meter test named Earendil-1 which the company has applied to launch in 2026. It would eventually be followed by about 4,000 satellites in orbit by 2030, according to the latest reports.

So how bad would the be? And perhaps more importantly, can Reflect Orbital’s satellites even work as advertised?

Bouncing sunlight

In the same way you can bounce sunlight off a watch face to produce a spot of light, Reflect Orbital’s satellites would use mirrors to beam light onto a patch of Earth.

But the scale involved is vastly different. Reflect Orbital’s satellites would orbit about 625km above the ground, and would eventually have mirrors 54 meters across.

When you bounce light off your watch onto a nearby wall, the spot of light can be very bright. But if you bounce it onto a distant wall, the spot becomes larger—and dimmer.

This is because the sun is not a point of light, but spans half a degree in angle in the sky. This means that at large distances, a beam of sunlight reflected off a flat mirror spreads out with an angle of half a degree.

What does that mean in practice? Let’s take a satellite reflecting sunlight over a distance of roughly 800km—because a 625km-high satellite won’t always be directly overhead, but beaming the sunlight at an angle. The illuminated patch of ground would be at least 7km across.

Even a curved mirror or a lens can’t focus the sunlight into a tighter spot due to the distance and the half-degree angle of the sun in the sky.

Would this reflected sunlight be bright or dim? Well, for a single 54 meter satellite it will be 15,000 times fainter than the midday sun, but this is still far brighter than the full moon.

The balloon test

Last year, Reflect Orbital’s founder Ben Nowack posted a short video which summarized a test with the “last thing to build before moving into space”. It was a reflector carried on a hot air balloon.

In the test, a flat, square mirror roughly 2.5 meters across directs a beam of light down to solar panels and sensors. In one instance the team measures 516 watts of light per square meter while the balloon is at a distance of 242 meters.

For comparison, the midday sun produces roughly 1,000 watts per square meter. So 516 watts per square meter is about half of that, which is enough to be useful.

However, let’s scale the balloon test to space. As we noted earlier, if the satellites were 800km from the area of interest, the reflector would need to be 6.5km by 6.5km—42 square kilometers. It’s not practical to build such a giant reflector, so the balloon test has some limitations.






So what is Reflect Orbital planning to do?

Reflect Orbital’s plan is “simple satellites in the right constellation shining on existing solar farms”. And their goal is only 200 watts per square meter—20% of the midday sun.

Can smaller satellites deliver? If a single 54 meter satellite is 15,000 times fainter than the midday sun, you would need 3,000 of them to achieve 20% of the midday sun. That’s a lot of satellites to illuminate one region.

Another issue: satellites at a 625km altitude move at 7.5 kilometers per second. So a satellite will be within 1,000km of a given location for no more than 3.5 minutes.

This means 3,000 satellites would give you a few minutes of illumination. To provide even an hour, you’d need thousands more.

Reflect Orbital isn’t lacking ambition. In one interview, Nowack suggested 250,000 satellites in 600km high orbits. That’s more than all the currently catalogued satellites and large pieces of space junk put together.

And yet, that vast constellation would deliver only 20% of the midday sun to no more than 80 locations at once, based on our calculations above. In practice, even fewer locations would be illuminated due to cloudy weather.

Additionally, given their altitude, the satellites could only deliver illumination to most locations near dusk and dawn, when the mirrors in low Earth orbit would be bathed in sunlight. Aware of this, Reflect Orbital plan for their constellation to encircle Earth above the day-night line in sun-synchronous orbits to keep them continuously in sunlight.

Bright lights

So, are mirrored satellites a practical means to produce affordable solar power at night? Probably not. Could they produce devastating light pollution? Absolutely.

In the early evening it doesn’t take long to spot satellites and space junk—and they’re not deliberately designed to be bright. With Reflect Orbital’s plan, even if just the test satellite works as planned, it will sometimes appear far brighter than the full moon.

A constellation of such mirrors would be devastating to astronomy and dangerous to astronomers. To anyone looking through a telescope the surface of each mirror could be almost as bright as the surface of the sun, risking permanent eye damage.

The light pollution will hinder everyone’s ability to see the cosmos and light pollution is known to impact the daily rhythms of animals as well.

Although Reflect Orbital aims to illuminate specific locations, the satellites’ beams would also sweep across Earth when moving from one location to the next. The night sky could be lit up with flashes of light brighter than the moon.

The company did not reply to The Conversation about these concerns within deadline. However, it told Bloomberg this week it plans to redirect in ways that are “brief, predictable and targeted”, avoiding observatories and sharing the locations of the satellites so scientists can plan their work.

The consequences would be dire

It remains to be seen whether Reflect Orbital’s project will get off the ground. The company may launch a test satellite, but it’s a long way from that to getting 250,000 enormous mirrors constantly circling Earth to keep some solar farms ticking over for a few extra hours a day.

Still, it’s a project to watch. The consequences of success for astronomers—and anyone else who likes the night sky dark—would be dire.

Provided by
The Conversation


This article is republished from The Conversation under a Creative Commons license. Read the original article.The Conversation

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Why Is Alexa+ So Bad?

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Why Is Alexa+ So Bad?



I stuck Amazon’s Echo Show 15 and its Alexa+ AI assistant in my kitchen for a month. Things have not gone well.



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The War on Iran Puts Global Chip Supplies and AI Expansion at Risk

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The War on Iran Puts Global Chip Supplies and AI Expansion at Risk


South Korean officials have warned that the US-Israel war with Iran could hit the global semiconductor supply chain if it disrupts the flow of critical industrial materials from the Middle East.

South Korea’s semiconductor sector, led by giants like Samsung Electronics and SK Hynix, produces about two-thirds of the world’s memory chips. If the Middle East’s supply of chipmaking materials is disrupted, semiconductor production could slow unless alternative sources are found quickly.

The Helium Problem

One material at risk is helium, which is essential in chip manufacturing for managing heat, detecting leaks, and maintaining stable temperatures in fabrication equipment. For many of these uses, there is no real substitute.

About 38 percent of the world’s helium is produced by Qatar, where large extraction facilities are tied to the natural gas industry. This concentration means that disruptions can quickly ripple through the global supply chain.

National oil company QatarEnergy declared force majeure on March 4, after stopping its gas production and downstream operations due to ongoing attacks. Downstream facilities turn gas into other products, including urea, polymers, methanol, and aluminum.

South Korea’s Industry Ministry said the country also depends on the Middle East for 14 other materials in chipmaking, such as bromine and some chip-inspection equipment. While some of these materials can be sourced domestically or from other markets, shifting suppliers in the semiconductor sector is difficult because chipmakers need to test and validate new sources to meet strict purity standards.

Companies say the situation is manageable for now. As reported by Reuters, SK Hynix said it has secured diverse supply chains and maintains sufficient helium inventories, adding that there is “almost no chance” its operations would be affected in the near term.

Contract chipmaker TSMC similarly said it does not currently anticipate a significant impact, while GlobalFoundries stated it is in direct contact with suppliers and has mitigation plans in place.

Stuck in Transit

Even if Qatar’s gas production restarts, the semiconductor industry is vulnerable to disruptions in regional shipping routes. Much of the world’s energy and petrochemical exports from the Persian Gulf pass through the Strait of Hormuz, a key maritime choke point.

If shipping through this corridor is interrupted for an extended period, it could slow the movement of industrial gases and petrochemicals that chipmakers rely on. Disruptions to oil and gas exports from the region have also already pushed global energy prices higher: Brent crude, the European benchmark, is priced at $80 per barrel at the time of publication.

Energy costs are a major factor in semiconductor production. Fabrication plants run large clean rooms that need constant electricity and cooling, so chipmakers are sensitive to changes in global energy prices. Industry representatives in South Korea warned that a prolonged conflict could push energy prices higher, likely leading to higher semiconductor production costs and potentially higher chip prices.

These risks come as semiconductor supply chains are already stretched by growing demand from AI computing. Chip demand from AI data center operators has tightened supply across several electronics sectors, including smartphones, laptops, and automobiles.

A Long-Term Problem

For now, the immediate impact on chip production is unclear. Major chipmakers usually maintain a mix of suppliers and stockpile specialty gases and chemicals to help weather short-term disruptions.

But if instability in the region continues, pressure on supply chains will likely grow. A drawn-out conflict that hits energy infrastructure, export facilities, or shipping routes could slowly squeeze the global supply of materials needed for chipmaking.

This could delay plans by major technology companies to expand artificial intelligence infrastructure in the Middle East. Firms such as Amazon, Microsoft, and Nvidia have been positioning the UAE as a hub for AI computing capacity.

This story originally appeared on WIRED Middle East.



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Save up to $600 With These Mattress Firm Coupons and Deals

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Save up to 0 With These Mattress Firm Coupons and Deals


Chances are that when you google “mattress store near me,” one of the first results you will see is Mattress Firm. This brick and mortar titan carries both established mattress brands like Serta and Sealy, as well as many online brands, like Purple, letting you go see for yourself if it’ll be the mattress for you. And if you were looking for an excuse to hop in the car and head over, we have a Mattress Firm coupon available right now, as well as tons of Mattress Firm promo codes to save big on those big (and small) purchases. Fingers crossed that you could start sleeping better, potentially as soon as tonight.

Upgrade Your Sleep Sale: Save Up to $600 (Plus Get a Free Adjustable Base)

This year, Mattress Firm wants to make it even easier (and more affordable) to upgrade your sleep with the Upgrade Your Sleep Sale. During this sale, you can save up to $600 and get a free adjustable base included on select mattresses, through April 28. You’ll receive a free Sleepy’s Basic adjustable base (a $300 value) with select mattress purchases—this means a free queen adjustable base with a  minimum $499 purchase, or free king adjustable base with minimum $599 purchase.

Get 15% Off When You Sign Up for Emails

To make sure you never miss out on Mattress Firm discount codes, you can sign up for email notifications. By doing so, you automatically get one! You can get an extra 15% off on your first order. Heads up that it can’t be combined with other coupons, nor can it be applied to specific brands and models, including Nectar, Purple, Sealy Hybrid, Tempur-Pedic, Stearns & Foster, and Serta iComfort.

Free Adjustable Base (Up to $499 Value) With Select Mattresses

First and foremost, make sure you have or are getting a mattress that’s compatible with an adjustable base. If you’re all set bed-wise, but have been looking for the right time to buy an adjustable base, consider this your sign: select mattresses come with a free adjustable base (up to $499 value). At last, you can sit up in bed or kick up your feet to your heart’s content.

Score Up to $300 in Instant Credits and Gifts

Mattress Firm’s got a gift for you, just ‘cuz. For those eyeballing Tempur-Pedic, Sealy, and Sterns & Foster in particular, it’s your lucky day, as there are Mattress Firm coupon codes for all three of these brands.

Starting with Tempur-Pedic, when you buy a qualifying Tempur-Pedic mattress, you can receive a $300 Instant Credit on these adjustable bases: Tempur-Ergo, Tempur-Ergo Smart Base, Tempur-Ergo ProSmart Base, Tempur-Ergo ProSmart Air Base, or the Sealy Ease Base. Use code TEMPURGIFT. You can also get a $300 credit toward these same adjustable bases when you purchase a qualifying Stearns & Foster mattress: use code STEARNSGIFT at checkout.

Lastly, if you wanted to pair a Sealy mattress with the Sealy Ease adjustable base (or any of the aforementioned adjustable bases), there’s a Mattress Firm coupon for that, too. Use code SEALYGIFT at checkout, and get a $200 Instant Credit on select Sealy and Tempur-Pedic adjustable bases.

Take 20% Off With Military, Medical, Student, or Teacher Discounts

Sleep is a necessity for everyone. But for those who work all day on their feet, and have to be dialed in at all times, sleep is critical. This is especially true for first responders, nurses, doctors, and medical professionals. As a way to say “thank you” for all that you do, there’s a special mattress firm discount just for you. Use the Mattress Firm first responder discount for 20% off select purchases. It’s for one-time use, but renews every 90 days when you re-verify your status.

For military members, as a way to thank you for your service, you can use the Mattress Firm military discount for 20% off select purchases as well. It’s a one-time use code, but re-verify your status every 90 days, and you can get a new one!

If you’re a teacher or student, there’s also a Mattress Firm discount for you, too. To help you bounce back after long days teaching, or late nights studying, use this Mattress Firm student discount code for 20% off select purchases. Like the first responder and military coupons, it’s a one-time usage code that can be renewed every 90 days when you re-verify your status.



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