Large constellations of small satellites will significantly increase the number of objects orbiting the Earth. Satellites burn up at the end of service life during reentry, generating aluminum oxides as the main byproduct. These are known catalysts for chlorine activation that depletes ozone in the stratosphere. We present the first atomic-scale molecular dynamics simulation study to resolve the oxidation process of the satellite's aluminum structure during mesospheric reentry, and investigate the ozone depletion potential from aluminum oxides. We find that the demise of a typical 250-kg satellite can generate around 30 kg of aluminum oxide nanoparticles, which may endure for decades in the atmosphere. Aluminum oxide compounds generated by the entire population of satellites reentering the atmosphere in 2022 are estimated at around 17 metric tons. Reentry scenarios involving mega-constellations point to over 360 metric tons of aluminum oxide compounds per year, which can lead to significant ozone depletion.
SpaceX has been receptive to design changes to starlink in the past to minimize impact, like decreasing reflectivity and reflection angles for astronomers. They might be receptive to moving to different alloy for the body construction.
Magnesium comes to mind that would be light but expensive. Steel alloys might be cheap and heavy options for later when starship is operational. Would those have similar effects on ozone, or is it only the aluminum oxides?
Before anyone jumps on the Anti-Musk train, read the article, please. They admit that they don't understand the complications that could arise and that they don't have any hard figures for the damage being caused. I'll be the first to jump in and say that it's probably a bad thing to just let metals burn in in atmo, but let's make sure we discuss the facts, and not just the politics of the potential polluter.
Quite possible. Let's fix our ISPs so that all of humanity has access to bandwidth priced to a value that they can afford for their area. A huge project that means lots of union jobs and an economic payoff for decades. If we pull this off Starlink won't have any customers except very marginal cases.
Fix the problem directly instead of fixing the solution unintended side effects
You would think space engineers would‘ve run those numbers before sending tens of thousands of them in orbit. It‘s really annoying that we can only hope for the best at this point.
About 48 tons of meteorites enter the atmosphere every day. I couldn't find the elemental distribution, but I'd guess there is some aluminum in there. How much of an increase is 14 tons aluminum per year over the many tons of aluminum entering the atmosphere already? That might be good to get a rough estimate of how impactful this is.
damn, starlink is my only way to access the internet. I wish there were an alternative that's usable. Traditional access providers don't work and cell data is extremely slow and there's no coverage where I live. I pay for Starlink with a bitter taste
So they take 17 tons of emissions (from all satellites, not just starlink), which are basically nothing on an atmospheric scale, then extrapolate that to 360 and start freaking out. Peak quality journalism.
At least the article came with the numbers. Given what I regularly read about all the pollutants we daily pump into the atmosphere, the numbers in this article for the materials being atomized is...well, they're very small in scale.
Basically, if a few hundred tons per year is hurting the ozone (and other things), just imagine what the billions of tons per year of emissions does.
Its good to keep an eye out for new sources of pollution, but the possible ozone depletion from satellites burning up is a tiny tiny fraction of what we're doing on Earth right now for pollutants.
One thing to note - The science is still calculating. Yet. SpaceX (and presumably others) are allowed to continue and increase what they're doing. This is the bass ackwards way to protect future us.
Its the same mentality as driving in a random direction for 20 minutes while someone looks in the car for the map on the off chance that when you get the map open you'll be where you wanted to be anyway.
It has the potential (and at this point, just the potential) for planet level changes, and is being done by one group. Should I, a random dude, be able to do something that might possibly affect the entire planet, and the planet as a whole just have to wait and see how it turns out?
The hopeful thought that its probably nothing, before anyone can prove that it's probably nothing, makes a bet where the short term wins are mine, but any long term losses are everyone else's.
The roughly 10-centimetre-long cube is made of magnolia-wood panels and has an aluminium frame, solar panels, circuit boards and sensors. The panels incorporate Japanese wood-joinery methods that do not rely on glue or metal fittings.
When LignoSat plunges back to Earth, after six months to a year of service, the magnolia will incinerate completely and release only water vapour and carbon dioxide
While researchers have largely focused on the pollutants being released by rockets as they launch, we've only begun to understand the implications of having thousands of retired and malfunctioning satellites burn up in the atmosphere.
"Only in recent years have people started to think this might become a problem," said coauthor and University of Southern California astronautics researcher Joseph Wang in a statement.
Since it's practically impossible to get accurate readings from the kind of pollutants satellites release as they scream back through the atmosphere, scientists can only estimate their effects on the surrounding environment.
By studying how common metals used in the construction of satellites interact with each other, the team estimated that the presence of aluminum increased in the atmosphere by almost 30 percent in 2022 alone.
They found that a 550-pound satellite generates roughly 66 pounds of aluminum oxide nanoparticles during reentry, which would take up to 30 years to drift down into the stratosphere.
"The environmental impacts from the reentry of satellites are currently poorly understood," the researchers note in their paper.
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