Concentrations of dangerous pollutants from rocket launches and satellite reentries in Earth's upper atmosphere might reach treacherous tipping points if constellations of hundreds of thousands of orbiting data centers get deployed in the next decade, experts say.

There's no question that Earth has an AI data center problem. By 2030, AI data centers may be responsible for up to 17% of electricity consumption in the U.S., according to a forecast by the Electric Power Research Institute. New fossil fuel power plants are being built to feed the growing demand for electricity, and aging ones are kept online despite decarbonization plans. On top of that, huge amounts of water are taken from already strained reservoirs to cool the computers.

Companies such as SpaceX, Amazon and Blue Origin say they have a solution: moving the power-hungry data crunching infrastructure into space, where solar power is easy to produce, and heat can be radiated out into the frigid vacuum. Combined, those companies have filed applications to the U.S. Federal Communications Commission to launch more than a million orbiting data centers in the next 10 years. Most of those will belong to SpaceX, if all goes to plan; Elon Musk has said the company wants to operate a million-satellite AI constellation all by itself.

The plans are making atmospheric scientists tear their hair out. If all these projects come to fruition, the number of satellites being launched to space and reentering the atmosphere will increase 100 times compared to today's numbers.

Moreover, the data center satellites will be much larger than the spacecraft orbiting Earth today. This large mass will translate into higher quantities of polluting propellant needed to loft these systems off Earth and a much larger amount of metals vaporizing in Earth's atmosphere during reentry. Neither is good news for our planet's air.

Pristine upper atmosphere

"Launches and the reentries are really the only things that humans do that deposit material directly into the upper atmosphere," Aaron Boley, an astronomy professor and space sustainability researcher at the University of British Columbia, told Space.com. "And the way things mix in the upper atmosphere means that the launch and reentry emissions are by far more impactful."

Most rockets emit black carbon, which could worsen global warming. Satellite bodies are mostly made of aluminum, which likely turns into aluminum oxide when burned in the presence of oxygen. Aluminum oxide is known for its ability to trigger ozone depletion, a hazardous process that was successfully thwarted by the Montreal Protocol of 1987.

Currently, scientists don't have a precise understanding of the chemical reactions that occur between the pollutants and the atmospheric gases at high altitudes. They also don't understand the tipping points, which may mean the difference between minor and major impacts on the climate. What is worse, pollutants in the upper atmosphere remain much longer than those emitted by cars and factory chimneys close to the ground.

"Close to the ground, we have rain and wind that removes pollution from the atmosphere within weeks," Eloise Marais, a professor of atmospheric chemistry at University College London, told Space.com. "If we put it into the higher layers of the atmosphere, we rely on very slow atmospheric processes to bring this pollution back down."

Too many launches

Black carbon from rockets, for example, can stay in the atmosphere for three years, scientists think, meaning its concentrations could dangerously rise in the near future.

SpaceX's Starship megarocket is likely to play a key role in the deployment of data center constellations. Unlike SpaceX's current workhorse launcher Falcon 9, which burns a form of the aviation fuel kerosene, Starship combusts the much cleaner combination of methane and liquid oxygen. But Marais cautions that Starship's size and the much more frequent launches that will be needed to deploy the vast constellations would result in an overall increase in the pollution injected into the upper atmosphere.

"Starship is a bigger rocket burning more propellant," Marais said. "So, in terms of each rocket launch, the difference almost offsets. It has potential per launch to produce quite similar amounts of black carbon."

Andrew Wilson, a space sustainability researcher at Glasgow Caledonia University in the U.K., told Space.com that every single Starship launch produces around 76,000 metric tons of carbon dioxide equivalent. That's about as much as 17,727 gasoline-powered passenger cars emit in a year.

And up to 77,000 Starship launches — some 15,300 per year — might be needed, according to estimates by Ars Technica, to deploy SpaceX's planned million-data-center constellation. That's a lot of rocket pollution added into the atmosphere. For comparison, there were just 324 orbital rocket liftoffs globally in 2025, according to Space News.

The space junk rain

Then there is the toxic ash from reentering satellites. Today, nearly 19,000 operational and defunct satellites orbit Earth, according to the European Space Agency. Currently, the most numerous type of satellite in Earth orbit is SpaceX's Starlink V2 Mini, each of which weighs about 1,760 pounds (800 kilograms). But SpaceX's orbital data centers are likely to be much more massive. Featuring solar arrays 246 feet (75 m) wide, every data center satellite might weigh up to 7.5 metric tonnes, according to available estimates.

Industry insiders expect that SpaceX and other providers would want to replace their AI satellites every five years with newer technology, as they do with existing communications satellites. As a result, tens or even hundreds of tons of metal may be reentering the atmosphere every year in the future, exceeding the amount of natural space rock that hits the planet.

The materials that satellites are made of are not naturally present in Earth's atmosphere, which means the consequences of such reentries can be unpredictable.

"Only 10 years ago, the reentries were not really a concern, because there were much more natural meteorites entering the atmosphere per year," Wilson said. "But if you have hundreds of thousands or millions of satellites in space at any one time, you are essentially going to create a rain of man-made materials, electronic equipment and metals that otherwise wouldn't be coming into the atmosphere."

He added that the situation is akin to ongoing climate change, which shows no signs of slowing down as humanity has so far failed to reduce carbon emissions.

"This is the most objects we've ever had in space, and we're continuing to propose more and more and more and more and more," Wilson said. "And there seems, in my opinion, to be very little consideration for the environment."

Not enough funding is currently flowing into research to answer the unknowns, Marais added.

"We need way more observations and way more time to be able to look into that," she said.

Boley concurred: "We absolutely have to understand, and we have to understand that before we actually launch a million satellites. Not that we launch them and wait [to see] what happens."

The plans of the satellite companies are stirring protests also among astronomers, who fear that the light pollution the constellations create will impact astronomical observations. A recent study by the European Southern Observatory concluded that, if all currently planned satellite constellation projects were to be built, astronomical research from the surface of Earth would no longer be possible.

Rocket Lab plans to start launching even more frequently and flexibly, thanks to a new portable spaceport system called "GHOST."

GHOST — short for "Global Hypersonic & Orbital Spaceport Technology" — turns the company's "Electron and HASTE rockets into a launch-anywhere, launch-anytime capability for multi-launch flight campaigns and critical national security missions," Rocket Lab representatives said in a statement today (Aug. 10).

"Packaged entirely within standard shipping containers, GHOST deploys complete rockets, launch infrastructure, ground support and range control systems anywhere in the world," they added.

Electron is Rocket Lab's workhorse orbital rocket, giving small satellites dedicated rides to the final frontier. The expendable 59-foot-tall (18-meter-tall) launcher debuted with a test flight in 2017 and has 83 missions under its belt to date.

As its full name suggests, HASTE ("Hypersonic Accelerator Suborbital Test Electron") is a suborbital version of Electron that customers use to test various technologies in the hypersonic flight environment. HASTE first flew in June 2023 and has flown nine times to date, most recently in June of this year.

Rocket Lab currently flies from two different launch sites — one on the North Island of company founder and CEO Peter Beck's native New Zealand and one at Wallops Island in Virginia. But the company recently announced plans to fly out of Alaska's Pacific Spaceport Complex as well, and GHOST will expand its launch footprint even further.

"Electron and HASTE revolutionized small orbital launch and hypersonic testing. Now we're making it easier to deploy them wherever they're needed most, whether that's for missile defense testing or sovereign orbital launch capability," Beck said this afternoon during Rocket Lab's second-quarter 2026 earnings call.

"We've mastered the art of building launch sites," he added. "Now we're making them deployable worldwide."

Rocket Lab intends to deploy its two planned pads at the Pacific Spaceport Complex using GHOST, Beck said during the call. The company was inspired to develop the portable spaceport system, he added, to meet the needs of a HASTE customer, who expressed a desire for Rocket Lab to be "a little bit more mobile than we are."

Rocket Lab currently flies out of two pads at its New Zealand site and one at Wallops, though it has built a second pad at the Virginia facility to accommodate launches of its coming Neutron rocket.

Neutron will be bigger and more powerful than Electron, and partially reusable as well; its first stage is designed to come back to Earth for recovery and reflight, like SpaceX's Falcon 9.

Rocket Lab originally wanted to fly Neutron for the first time in 2024, but the new launcher has yet to leave the ground. Such delays aren't uncommon in the case of new rockets, and the company is making considerable progress with Neutron, according to Beck.

"Every part of the vehicle has now seen significant testing," he said during today's call. "As with any complex development program, we've had to tweak a few things along the way, but we're moving now into final checkout and assembly of all of our flight hardware before integrating them at the pad."

The company is on target to deliver the first Neutron to that Wallops pad in the fourth quarter of this year, Beck added.

China's latest rocket launch ended in failure this morning, lighting up the skies with some unwanted fireworks.

The state-owned China Aerospace Science and Technology Corporation (CASC) launched a Long March 7A rocket today (Aug. 10) from the Wenchang Space Launch Site, in the country's Hainan province, just after 8:00 a.m. EDT (1200 GMT; 8:02 p.m. local time). Around 85 seconds into the launch, the rocket exploded, generating a massive fireball and a cloud of smoke and debris while still soaring through Earth's atmosphere.

CASC had not yet released a statement about the incident by the time of this story's publication, but video reposted to social media captured the shock of onlookers the moment that the rocket burst into flames. Based on such views, the mission will almost certainly be deemed a complete failure, with total loss of vehicle and payload.

Today's launch was the 18th Long March 7A mission since the rocket's debut in 2020, which, subsequently, also ended with the vehicle's explosion. China traced that mishap to an engine malfunction that occurred shortly after first-stage separation. This morning's launch, however, didn't get that far.

The Long March 7A's four side boosters and core stage detach as a full cluster during first stage separation, which typically occurs just under three minutes after liftoff. As today's incident occurred just 85 seconds into flight, the rocket was still engaged in the main stage's initial engine burn to escape Earth's atmosphere.

The 7A — a variant of China's Long March 7 rocket family — stands just over 197 feet (60 meters) tall and combines the first two Long March 7 stages with a hydrolox (liquid hydrogen and liquid oxygen)-powered third stage capable of launching up to 7 tons to geostationary transfer orbit (GTO).

According to China National Radio, today's launch carried China's Zhongxing-4B spacecraft,, a communications satellite presumably bound for GTO. China's Zhongxing satellites provide telecommunications and broadband internet services and are also thought to provide services for China's military.

It is unclear what repercussions today's explosion may have on upcoming launches, including a Chinese Zhuque-3 rocket liftoff scheduled for Monday evening. That mission is scheduled to fly from China's Jiuquan Satellite Launch Center, more than 1,500 miles (2,415 kilometers) from Wenchang, at 7:45 p.m. EDT (2345 GMT; 7:45 a.m. local time), and is expected to feature a first-stage landing attempt.

CASC uses the standard Long March 7 rocket, which shares its core stage with the 7A, as its launch vehicle for delivering cargo to the Tiangong space station in low Earth orbit about every eight months. The most recent of those missions launched in May, putting the next resupply launch sometime around January 2027. Depending on the cause of this morning's explosion, that mission and others could face delays as China investigates the incident.

Editor's note: This story was updated at 4:20 p.m. ET on Aug. 10 with new photos of the launch.

On Aug. 10, 1972, an Earth-grazing fireball burst through the sky over North America. It didn't hit the ground, but instead it passed straight through the sky.

The fireball entered the atmosphere somewhere over Utah and passed northwards, leaving the atmosphere over Alberta, Canada about 100 seconds later.

Analysis of its trajectory showed the object was about 10 to 45 feet in diameter, depending on whether it was an icy comet or a denser, rocky asteroid.

Why it mattered

When we think of fireballs, we typically think of "shooting stars" during a meteor shower: a night sky spectacle that's brief but brilliant. But a daytime fireball is something else altogether.

Nighttime meteors are typically tiny particles of space dust or rocks that burn up as they streak through Earth's atmosphere. While they look impressive in the night sky, they're relatively dim. City streetlights or even a bright full moon can outshine them.

But a daytime fireball is caused by something large enough to be visible in the sky in broad daylight, something large and fast enought to light up a sky brighter than a sunlit day. That's what happened today in 1972.

Today, an event like the "Great Daylight Fireball" of 1972 (as it came to be named) would be visible to potentially millions of witnesses as it streaked over the United States and Canada, and we'd likely see social media flooded with images and video. There is at least one reported video of the 1972 event you YouTube, but nothing compared to what we'd see if it happened today.

Japan's H3 rocket flew for the ninth time ever this afternoon (Aug. 10).

The H3 lifted off from Tanegashima Space Center today at 3:23 p.m. EDT (1923 GMT; 4:23 a.m. on Aug. 11 local time), carrying the Michibiki 7 navigation satellite aloft.

The H3's upper stage deployed Michibiki 7 into its target orbit 29 minutes later, eliciting cheers from the folks in mission control.

The two-stage H3 is the successor to Japan's workhorse H-2A rocket, which retired last year after a total of 50 flights.

The H3 — which stands 187 feet or 207 feet (57 or 63 meters) tall, depending on what type of payload fairing it employs — debuted in March 2023 and had eight liftoffs under its belt before today.

Two of those eight were failures — the debut flight and the launch of Michibiki 5 in December of last year. But the H3 bounced back from that latter anomaly two months ago, successfully delivering six satellites to orbit on June 11.

Michibiki 7 will be part of Japan's Quasi-Zenith Satellite System (QZSS), a homegrown navigation system that operates high above Earth in geosynchronous orbit.

"This system is compatible with GPS satellites and can be utilized with them in an integrated fashion," Japanese officials wrote in a description of the QZSS project. "QZSS can be used even in the Asia-Oceania regions with longitudes close to Japan, so its usage will be expanded to other countries in these regions as well."

The QZSS network will eventually consist of 11 satellites, if all goes according to plan. There are five such spacecraft operating in orbit at the moment.

Michibiki 7 is carrying a payload for the United States as well — the Situational Awareness Camera Hosted Instrument (SÃCHI), which was developed for the U.S. Space Force by the MIT Lincoln Laboratory. This is the second of two SACHIs to go up on a QZSS satellite; Michibiki 6, which launched atop an H3 in February 2025, hosts the other one. (Yes, Michibiki 6 launched before Michibiki 5.)

"This program will allow the United States to monitor satellite behavior within the GEO belt over a very interesting part of the world," Mark Huber, a technical staff member in the Lincoln Laboratory's Space Systems and Technology Division, said in a statement in December 2020.

"It is also a pathfinder in several ways," he added. "The U.S. team is blueprinting methods to allow sensitive data sharing between the United States and Japan."

Editor's note: This story was updated at 3:55 p.m. ET on Aug. 10 with news of successful launch and satellite deployment.