I remember the first time I saw a satellite. I was a teenager, standing in my mildly light-polluted suburban yard and doing my usual stargazing. The satellite was a faint “star” moving slowly and smoothly across the sky, and as I watched it, I felt a mix of awe and wonder that such a thing could be seen—and that humans could put an object into orbit at all.
That was a lifetime ago, and I now look back on that evening with more discomfiture than nostalgia; my adolescent naivete feels almost embarrassing.
That’s because, these days, seeing one of those celestial travelers fills me with dread. We are firmly in the era of the satellite constellation—groups of dozens of similar satellites—and are currently entering the era of the mega constellation, wherein groups of thousands of satellites swarm the skies. The clusters of satellites started small, but, like a viral outbreak, they grew almost without us noticing—and now we’re dealing with a pandemic.
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I wrote about this problem for Scientific American in May 2023. At the time, there were 7,500 active satellites orbiting Earth; more than half of them were SpaceX Starlink satellites that provided Internet service. In a little under three years, the number of just Starlink satellites in orbit has reached nearly 10,000. Today there are literally more Starlink satellites up there than the sum total of all other operational satellites.
This ratio will almost certainly get more skewed toward Starlink, too; back in 2019, when the first Starlink satellites were launched, SpaceX filed with the Federal Communications Commission (FCC) for up to 30,000 additional satellites.
Does that sound bad? Well, there may come a day, all too soon, when we’re nostalgic for such a small a number of satellites cluttering the sky. On January 30, 2026, SpaceX filed for permission to launch as many as one million more satellites.
Yes, one million.
SpaceX’s plan is for this sprawling mega constellation to become a distributed network operating as an orbital data center, similar to ground-based data centers that provide the information processing backbone of the Internet. In this case, instead of having equipment capable of all that processing power stored in massive warehouses, each satellite in orbit would do a small part of the number crunching and then beam the final results back to the ground.
In principle, such plans could ease the insatiable power demands and environmental effects of ground-based centers. In 2023 data centers in just the U.S. consumed a staggering 176 million megawatt-hours of energy—a little more than 4 percent of the nation’s annual electricity usage and enough to power 16 million homes for a year. Many of these centers are powered by fossil fuels that add greenhouse gases into the atmosphere that worsen global warming. These centers also need to be cooled, and they typically consume vast amounts of water to do so. And as the use of computationally-intensive artificial intelligence soars, so, too, will the appetite for ever more power—and the potential for ever greater environmental harm.
Exporting most of that “compute” to orbit, SpaceX claims, is how to break this vicious cycle. And there is some truth to that: the satellites will be solar powered, easing the electricity demand on Earth. They also won’t need water to cool their hot chips but will instead rely on large radiators to vent heat—a slower, less efficient method but the best one available in the near-vacuum of space. Currently in-use Starlink satellites already cool themselves this way, and the heat load for a satellite used to process data would be roughly the same as one used to provide Internet, so this isn’t the showstopper problem many people assume it to be.
So, if you don’t look too deep, large-scale orbital data centers might make sense. Scratching the surface of this idea, however, shows just how colossally terrible it is.
First, those satellites need to get to space. As astrophysicist Jonathan McDowell, my friend and colleague, points out, SpaceX claims that its Starship rocket can (once it passes testing) take 150 metric tons to low-Earth orbit, but there are good reasons to think the real operational capacity will prove be more like 100 metric tons. Assuming that low-Earth orbit is in fact where all the satellites will go (and many will undoubtedly need to fly higher), and that they each are two metric tons, that means Starship can launch around 50 satellites at a time—so creating this mega constellation even under very optimistic assumptions would require some 20,000 Starship launches.
It gets worse: these satellites will fail after a few years and will need to be replaced. In the end, upkeep for this notional million-satellite mega constellation could take on the order of 10 Starship launches per day, forever.
The environmental effect of all this wouldn’t be trivial. A single Starship launch emits 76,000 metric tons of carbon dioxide equivalent, for example—leaving aside issues of noise pollution and potential damage to nearby habitats. Twenty thousand launches would have an immense effect, including more damage to our critical ozone layer. The fiery atmospheric reentries of satellites would be a source of pollution, too, dumping significant amounts of vaporized metal and plastic into our planet’s fragile upper atmosphere. At least one Starlink satellite is already burning up like this every day, based on when these satellites started entering orbit and their planned replacement cycles—and orbital data centers could make this reentry rate skyrocket.
As if this weren’t enough, a proliferation of mega constellations also carries risks for the orbital environment itself. The volume of satellites already over our head is huge, but the numbers of proposed satellites are so vast that space traffic management to avoid collisions would become an even more massive task. Even a single collision in orbit can become catastrophic; these satellites are moving at speeds many times faster than a rifle bullet, and a direct hit from one creates a cloud of shrapnel. That debris spreads, hitting other satellites and creating even more debris, resulting in a violent cascade called the Kessler syndrome. Triggering this syndrome is already a real concern, despite orbital decay naturally “cleaning” low-Earth orbit over time. Increasing the numbers of satellites by several thousandfold could make this threat apocalyptically worse.
And as an astronomer, I can’t help but worry over the effect on my beloved field. A study published last December in Nature showed that if there were roughly half a million satellites in orbit, at least one would contaminate essentially every observation taken by the Hubble Space Telescope. Ground-based telescopes would also be severely affected; they already are now! Vaporized debris from reentries will also add to sky glow, making it more difficult to see faint cosmic objects. Even simple stargazing from your backyard would be affected. In a very real sense, by launching so many satellites, we risk losing the sky.
Keep in mind that SpaceX is not the only one crowding the sky. China has filed to launch 200,000 satellites for its own network. Other countries and companies will no doubt follow suit; Amazon and Blue Origin already plan on launching thousands of satellites each as well. Even more concerning is a new company, called Reflect Orbital, that wants to launch thousands of giant space mirrors into orbit to provide “sunlight on demand” anywhere on Earth. The beams would be far brighter than the full moon and, even if carefully pointed, would scatter in the atmosphere to be very bright off-beam, disrupting wildlife and effectively destroying the sky’s remaining natural beauty by erasing the stars from our sight. These mirrors are a truly terrible idea.
That’s the common theme here, in fact. Even ignoring the deeply disturbing environmental and light pollution from all these launches and reentries, there is another effect. Our night sky—and it is ours—is a natural wonder, a cosmic park we need to preserve, not exploit with a laissez-faire attitude. This careless exploitation of the heavens above is a real danger to us all.
If all this appalls you as much as it does me, then make your voice heard. The FCC is taking public comments on Reflect Orbital’s filing until March 9, 2026, and on SpaceX’s megaconstellation until March 6 (the day this article is published). The American Astronomical Society has more information and links, as well as instructions on how to submit a comment. I did!
