Space junk pollution

 

Thousands of satellites that burn up in Earth’s atmosphere are leaving more than just streaks of light in the sky.

A groundbreaking study published in the Journal of Geophysical Research: Atmospheres has revealed that dying satellites – those burning up on re-entry after completing their missions in orbit – are releasing pollutants that could have alarming consequences for both the climate and ozone layer.

As satellite megaconstellations grow exponentially, the problem is no longer confined to a niche realm of astrophysics. It’s rapidly becoming a global environmental issue.

Today, there are more than 9,000 satellites orbiting Earth and by 2040 that number is predicted to swell to over 60,000. The driving force behind this growth is the rapid deployment of government and commercial satellite constellations, primarily for broadband internet coverage by companies such as SpaceX and Amazon.

But, as the saying goes, what goes up must come down – and when these satellites complete their missions after relatively short lifetimes, they are routinely deorbited to burn up in the atmosphere.

While this may seem like a tidy solution, it’s anything but clean. The study, led by atmospheric scientist Jamie Shutler and colleagues, finds that re-entering satellites release thousands of tonnes of metal particles into the stratosphere every year.

Chief among these is aluminum oxide (Al₂O₃), a substance with the potential to alter temperature patterns and disrupt delicate atmospheric chemistry.

The authors estimate that by 2040 as many as 10,000 metric tonnes of aluminum oxide could be entering the upper atmosphere annually. This figure represents a staggering increase compared to today’s levels and signals a future where human-made atmospheric contamination could rival or exceed that of natural processes like volcanic eruptions.

Aluminum oxide is no benign byproduct. According to the study, its presence can cause localised heating of up to 1.5C in the middle and upper atmosphere.

“These temperature changes could disrupt wind patterns and other critical dynamics of the stratosphere,” the authors warn.

Perhaps more disturbingly, these disruptions could delay the recovery of the ozone layer – a thin but vital shield that protects life on Earth from harmful ultraviolet radiation.

In an unusually short three paragraph article on its website The Guardian, in summarising the findings, quotes Shutler as saying: “This is a new, emerging chemical pathway that is completely anthropogenic. We are fundamentally changing the chemistry of the atmosphere in a way that has not been considered before.”

The satellite industry has long viewed atmospheric re-entry as a convenient and eco-friendly solution to space junk. But as this study makes clear, the process may be quietly shifting the baseline of Earth’s climate systems.

Particles produced during re-entry are not merely disbursed and forgotten. Instead, they form persistent aerosols that can act as radiative agents – essentially reflecting or trapping heat – while also playing a role in catalysing chemical reactions that destroy ozone.

Aluminum is not the only concern. The study also highlights the release of other metals such as titanium, iron, copper, and lithium – all of which have their own complex chemical interactions and unknown long-term impacts.

The exact consequences of this metallised upper atmosphere are still being modelled, but early signs point to a troubling new front in humanity’s planetary impact.

Researchers also note the increasing role of some rocket launches, particularly from private companies, which contribute additional pollutants like black carbon. Such compounds rise into the stratosphere, where they can remain for years, compounding the problem.

A 2022 study by the US National Oceanic and Atmospheric Administration (NOAA) warned that soot from rockets alone could increase stratospheric temperatures and disrupt polar vortexes. The new satellite re-entry data adds another layer to this growing concern.

Ironically, many of the satellites responsible for these emissions are part of systems designed to monitor and combat climate change. In attempting to connect the world and collect vital environmental data, we may be undermining the very systems that sustain life on Earth.

The implications of the study are sobering. The scientific community and regulatory bodies have, until now, paid scant attention to the effects of mass satellite re-entry. That’s likely to change. As one of the study’s co-authors bluntly put it: “We’re geoengineering the stratosphere without realising it.”

So, what now? The researchers call for urgent reforms to how we manage satellite end-of-life processes.

Alternatives could include designing spacecraft with minimal pollutant output on re-entry, retrieving and disposing of satellites differently, or even developing reusable systems that don’t require destructive descent at all.

These options will require international cooperation and new frameworks for space governance – something the UN’s Committee on the Peaceful Uses of Outer Space has only recently begun to explore.

Earth’s climate crisis has taught us at least one painful lesson: seemingly invisible emissions, once dismissed or underestimated, can have catastrophic consequences. Now, with space becoming the next industrial frontier, we must apply that lesson to the skies above.

Satellites may be our eyes in the heavens, but their burning remains are falling into our future. The time to act is now, while we still have the tools to prevent a new kind of environmental crisis.

As the paper’s authors conclude: “The cumulative effect of satellite re-entries must be taken seriously as part of Earth’s changing atmospheric budget.”

If we fail to heed this warning, the sky itself may become the next casualty of human excess.

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Article references:

Journal of Geophysical Research: Atmospheres - Investigating the Potential AtmosphericAccumulation and Radiative Impact of the Coming Increase in Satellite ReentryFrequency 

The Guardian - Dying satellites can drive climate change and ozone depletion

Taking over the night sky

UNTIL relatively recently in human history the night sky remained one of the last unspoilt vestiges of our natural world. From the time of Galileo to the present day, astronomical observations from Earth’s surface have led to exceptional progress in the scientific understanding of the world around us.

Now, just as we enter the second decade of the 21st Century and a dynamic new phase in space exploration and exploitation begins, some of the current capability of astronomical instrumentation from the ground is potentially being endangered by the rapid development of micro-satellite fleets in low Earth orbits (LEO).

In the interests of preserving the ability to make meaningful visual and radio ground-based observations, the International Astronomical Union (IAU) is sounding a clarion call for greater protection and international safeguards.

The IAU claims that if the deployment of mega constellations remains unchecked the view of the night sky will be increasingly impeded by artificial satellites, not only visible to the naked eye but also crossing and scarring professional and amateur time-lapse observations alike with parallel streaks at all latitudes.

SpaceX has already embarked on its ambitious Starlink project to populate the sky with some 42,000 satellites which, together with planned constellations such as those from OneWeb, Amazon and others, means there could one day be more than 50,000 small satellites encircling the Earth at different low altitudes.

These small, mass-produced satellites orbit very close to Earth with the intent to provide speedy internet connections via low-latency signals. But that proximity also makes them more visible and brighter in the night sky. 

Astronomers argue that such constellations will severely diminish our view of the universe, create more space debris and deprive humanity of an unblemished view of the night sky. If these networks come to fruition, they suggest that every square degree of the sky will eventually have a satellite crawling across it throughout the whole observing night.

As space becomes ever more commercialised the speed of such development is quickly overtaking the existing, globally agreed rules governing space activities. Mega-constellations are just one area where new rules of governance are urgently needed. Others include the exploitation of resources on the Moon and elsewhere, preserving peace and resolving disputes, and rules for everyday living in space.

Recognising the urgent need for coordinated action, the space nation Asgardia is organising a second congress in its ‘Paving the Road to Living in Space’ series. Taking place at McGill University in Montreal, Canada, in 2021 (www.alc.space), it will focus on discussing key aspects of space law needed to ensure the success of future space exploits.

Of course, ROOM fully supports the growth and advancement of space technologies and the ensuing benefits they bring to everyday life, business and commerce across the globe.

But it would be ironic indeed if, by exploiting LEO without due responsibility, we neglect to consider the resultant damage to scientific research and a previously unblemished part of our natural environment that deployment of such new technologies could unwittingly deliver.

The urgent question is, do we continue to rush headlong into deploying massive new orbital networks without checks and balances, and with scant regard for the heavens above - or can the global space community approach this kind of thing in a more mature and responsible manner that is fair to everyone?

This editorial by Clive Simpson was first published in the Summer 2020 issue of ROOM Space Journal

 

Johnson's satellite gamble

SHOULD the UK government be spending hundreds of millions of pounds on the part-purchase of bankrupt US satellite firm OneWeb, which it hopes to lever as a replacement for departing the EU’s Galileo system as a result of Brexit?

OneWeb, which has already had around $3 billion of investment from SoftBank, is the kind of high risk space company that has to spend vast amounts of money before being able to make any income and in an entirely new field against stiff competition.

Cash flow is a fact of life for such companies where potential returns are many years down the line. This spring OneWeb’s on-going problems, combined with the arrival of Covid-19, created a perfect storm and it was forced it to file for bankruptcy in the United States.

Since then it has been desperately hunting for a buyer with, among other groups from France and China, rival Amazon thought to have expressed interest. Intense lobbying by its officials is understood to have included the British government and its advisers.

So the UK government's plan is to invest £500 million to help rescue OneWeb as part of a wider private-sector consortium bid that would potentially see the British public holding a 20 percent stake in the company.

Under such a deal the UK would likely need OneWeb to transfer its manufacturing base from the United States to Britain. And, crucially, it would also be required to add an innovative new global positioning technology (possibly developed by the UK's 'Satellite Applications Catapult' to each of the thousands of low Earth orbit (LEO) satellites.

The government believes this would be cheaper than investing around £4 billion, as previously mooted, in developing a rival satellite navigation system to the EU's Galileo.

It should be emphasised that the UK is only unable to access the restricted, military secure areas of the EU’s Galileo satellites and this is not because of Brexit (Norway has full operational access under its Co-operation Agreement) but because the UK government has chosen not to withdraw cooperation on Galileo for ideological political reasons. The OneWeb bid is therefore couched in politics

To date all major global positioning systems – America’s GPS, Russia’s Glonass, China’s BeiDou, and Europe’s Galileo (an EU-led project that the UK helped design and build) is in a medium Earth orbit at a height of approximately 20,000 km. OneWeb’s satellites, 74 of which have already been launched, are in a low Earth orbit, just 1,200 km high.

OneWeb is working on basically the same idea as Elon Musk’s Starlink - a mega-constellation of satellites in low Earth orbit, which are used to connect people on the ground to the internet.

According to Dr Bleddyn Bowen, a space policy expert at the University of Leicester, replacing GPS for military-grade GPS systems (which need encrypted, secure signals that are precise to centimetres) is not necessarily possible on small LEO satellites like those developed by OneWeb.

He suggests that rather than being selected for the technical quality of the offering, the investment is more in line with “a nationalist agenda”.

One might argue the scheme has all the hallmarks and parallels to the triumphant exceptionalism of the hugely expensive and so far failed UK government plan during the Covid-19 crisis to go it alone and develop its own Track & Trace App, despite other technologies already existing.

The internet side of a fully developed OneWeb satellite system may also have other more dubious attractions to Dominic Cummings, the prime minister’s chief advisor and chief of the Vote Leave campaign - the potential for surreptitious data harvesting.
                      
Given that OneWeb has arrived at its current destination by spending a very large pile of money already on its core mission, and more will be needed to make it viable, there are still very sizeable financial risks for a public investment.

OneWeb remains an unproven business and is competing against established giants, such as SpaceX, which is about to launch its latest batch of Starlink satellites. Significant technical issues will need to be overcome too, all of which will cost a lot more money.

And, of course, such satellite mega-constellations are already attracting the wrath of astronomers for their potential to hamper astronomical observations (see Traffic lights in the night sky), as well as making an as yet undetermined contribution to the growing problem of orbital debris.

Boris Johnson’s potential participation in a OneWeb bid has been the focus of both  opposition and support from the UK space industry, which had originally pinned its hopes on pursuing a lucrative Galileo-style navigation project.

One deciding factor appears to have been support from US defence officials who do not want the UK to develop a replica of the American GPS or European Galileo systems. In contrast a LEO navigation service would complement the current US system and, according to some, offer extra resilience to US allies.

Certainly, as Brexit and all its down the line ramifications gradually unfold, the government’s latest bid signals a further departure from its previous close and highly successful associations with Europe towards a potentially much more unbalanced and risky trans-Atlantic partnership.

Clive Simpson is a freelance journalist specialising in global space affairs.

Traffic lights in the night sky

Starlink satellites leave diagonal lines as they pass through a telescope’s field of view.

UNITL relatively recently in human history the night sky remained one of the last unspoilt vestiges of our natural world. From the time of Galileo to the present day, astronomical observations from Earth’s surface have led to exceptional progress in the scientific understanding of the world around us.

Now, just as we enter the third decade of the 21st Century and a dynamic new phase in space exploration and exploitation begins, some of the current capability of astronomical instrumentation from the ground is potentially being endangered by the rapid development of micro-satellite fleets in low Earth orbits (LEO).

In the interests of preserving the ability to make meaningful visual and radio ground-based observations, the International Astronomical Union (IAU) is sounding a clarion call for greater protection and international safeguards.

The IAU claims that if the deployment of mega constellations remains unchecked the view of the night sky will be increasingly impeded by artificial satellites, not only visible to the naked eye but also crossing and scarring professional and amateur time-lapse observations alike with parallel streaks at all latitudes.

SpaceX has already embarked on its ambitious Starlink project to populate the sky with some 42,000 satellites which, together with planned constellations such as those from OneWeb, Amazon and others, means there could one day be more than 50,000 small satellites encircling the Earth at different low altitudes.

These small, mass-produced satellites orbit very close to Earth with the intent to provide speedy internet connections via low-latency signals. But that proximity also makes them more visible and brighter in the night sky. Astronomers argue that such constellations will severely diminish our view of the universe, create more space debris and deprive humanity of an unblemished view of the night sky. If these networks come to fruition, they suggest that every square degree of the sky will eventually have a satellite crawling across it throughout the whole observing night.

As space becomes ever more commercialised the speed of such development is quickly overtaking the existing, globally agreed rules governing space activities. Mega constellations are just one area where new rules of governance are urgently needed. Others include the exploitation of resources on the Moon and elsewhere, preserving peace and resolving disputes, and rules for everyday living in space.

Recognising the urgent need for coordinated action, next year the space nation Asgardia is organising a second congress in its ‘Paving the Road to Living in Space’ series. It will focus on discussing key aspects of space law needed to ensure the success of future space exploits.

Of course, ROOM fully supports the growth and advancement of space technologies and the ensuing benefits they bring to everyday life, business and commerce across the globe.

But it would be ironic indeed if, by exploiting LEO without due responsibility, we neglect to consider the resultant damage to scientific research and a previously unblemished part of our natural environment that deployment of such new technologies could unwittingly deliver.

The urgent question is, do we continue to rush headlong into deploying massive new orbital networks without checks and balances, and with scant regard for the heavens above - or can the global space community approach this kind of thing in a more mature and responsible manner that is fair to everyone?

Editorial (originally published under the title 'Mega-constellations raise awkward questions for space community') 
by Clive Simpson in the Spring 2020 edition of ROOM Space Journal