Waste of space: Just what happens to the junk we leave in orbit?
The first satellites in SpaceX’s 12,000-strong Starlink constellation launched on 23rd May 2019. Their mission: to bring high-speed, low-cost, space-based internet to the world. But what happens to pieces of space hardware like this when they die? In DG #35 we delved into the issue of orbital debris – a growing problem that until now has gone way over most people’s heads
23rd May 2019 (Taken from: #35)
Daan Roosegaarde lifts the display cover and delicately picks the plastic cube, the size of a tennis ball, off its pedestal. He hesitates briefly, then hands it to me. “Don’t drop it,” he says, sternly. “I’m serious. This is priceless.”
Encased in the cube is a discarded piece of solar panel, about an inch in height and chipped in one corner. The scrap would be quite worthless if it weren’t for its back story: it used to be part of the Hubble Space Telescope until it came off during repairs in the 1990s. “If it weren’t for the astronaut who [caught it and] brought it back to Earth, this would have been a piece of space waste,” says Roosegaarde. “It would have joined the more than eight million kilos of junk that is floating around above us as we speak.” I ask what would happen if the strip of solar panel collided with, say, the International Space Station. “It would be like a bomb,” says Roosegaarde. “At 27,000 kilometres an hour, it would just…” he says and snaps his fingers. Kaboom.
Roosegaarde is a Dutch designer and artist known for addressing environmental issues through his projects. Outside his Rotterdam studio stands one of his earlier creations, the smog-free tower, a 7m-tall air purifier which hoovers up nearby pollution particles.
Now he’s set his sights on the issue of space debris, the growing belt of rubbish circling our planet. Earlier this year he completed the first phase of his studio’s Space Waste Lab, an awareness-raising art installation featuring powerful green LED beams that sweep across the night sky tracking individual pieces of orbital debris in real time. With help from the European Space Agency (ESA), Roosegaarde now wants to develop methods to capture orbital debris and upcycle it into something else.
“This is junk, but it’s also an ingredient. What can we do with it? That’s what we’re working on,” he says, taking back his Hubble chunk. One idea Roosegaarde has explored is to collect space debris and use it as the base material for 3D-printed parts of the lunar base that US space agency Nasa wants to start building from 2028 onwards. Another is to gather the celestial rubbish together and fashion it into a giant solar reflector, a sort of in-orbit parasol to combat global warming.
The concept on which Roosegaarde is currently focusing his efforts is called ‘Shooting Stars’. The idea: to scoop space debris out of orbit with a net and direct it back towards Earth at a set time and place. The scraps will burn up when they enter the atmosphere, creating an awe-inspiring light show that’s visible on the ground. Roosegaarde hopes eventually to persuade events organisers to stop spending their money on polluting, expensive fireworks shows and start buying made-to-order showers of shooting stars instead.
Roosegaarde certainly won’t be short of materials. Since the 1957 launch of Sputnik I, the first satellite, humans have blasted a lot of stuff into space. We’ve been much less diligent about cleaning up after ourselves, and today entire derelict satellites, spent rocket stages and crystallised droplets of astronaut urine are circling the Earth at breakneck speeds.
Space agencies are currently tracking more than 22,300 artificial objects in orbit, less than 2,000 of which are functional satellites. But these are just the pieces that are big enough to track: in low Earth orbit, up to 2,000 kilometres around the planet, that’s anything larger than five centimetres across. Out in geostationary orbit, 35,786 kilometres above Earth, that’s anything bigger than 30 centimetres across. ESA estimates that over 128 million pieces smaller than that are zooming around up there.
The highest concentration of man-made space junk is in low Earth orbit. Within this band, orbital debris circulates at roughly 27,000 kilometres an hour. That even the tiniest speck of litter can cause big problems at such speeds was demonstrated in 2016, when British astronaut Tim Peake tweeted an image of a chipped window in the International Space Station, 408 kilometres above Earth. The likely culprit according to ESA: a fleck of paint or a piece of metal a few thousandths of a millimetre across. The perennially upbeat Peake kept a cool head about the window which, had it shattered, could have led to him and his fellow astronauts being sucked out into the black infinity of space. “Glad it’s quadruple glazed!” he said.
Just imagine the fallout if entire satellites collided with each other. Oh wait – that already happened.
On 10th February 2009, a defunct 900kg Russian satellite called Kosmos 2251 slammed into the active US-built commercial satellite Iridium 33, at 789 kilometres above the Siberian Taymyr Peninsula. Colliding at 11.7 km/s, the satellites broke up into 2,000 trackable fragments. Many of them remain in orbit today.
It was the first time two fully intact satellites had crashed in space and, in the US, it forced one man out of retirement. “Some people thought I was dead at that point,” says Donald J Kessler in his congenial Southern drawl. “One of my colleagues, Nick Johnson [then Nasa’s chief scientist for orbital debris] tells this story that they were planning a conference in which the collision would be addressed. Someone said, ‘We need somebody to talk about the Kessler syndrome,’ but nobody had any suggestions. Finally, Nick said, ‘How about Don Kessler?’”
Over the past four decades, Donald J Kessler’s name has become synonymous with the danger posed by orbital debris. In 1978, he published a paper in which he predicted that from around the year 2000 onwards, collisions between satellites would set in motion a chain reaction in which the debris they create leads to more collisions, sparking an exponential increase in the amount of space junk and the creation of “a belt of debris around the Earth”. This effect of “collisional cascading” has become known as the Kessler syndrome.
Kessler started wondering how long it would take for satellites to turn into a miniature man-made asteroid belt back in 1970, when he was working in a meteoroid research group at Nasa’s Manned Spacecraft Centre. Cutbacks and strategic pivots at the agency meant he kept getting reassigned away from orbital debris and by 1977, he was still only allowed to dedicate a meagre ten percent of his time to his passion project.
Everything we had accomplished in terms of minimising the further accumulation of debris, it just totally undid it”
Then, in 1978, things started to change. Kessler’s seminal paper on collisional cascading was published just a few months after the USSR’s satellite Kosmos 954 crashed back to Earth. Kosmos 954 had an onboard nuclear reactor, created to power the radar and radio it used to spy on US navy ships, and as it descended it sprinkled radioactive debris across large tracts of northern Canada. One theory about its demise was that the satellite had malfunctioned after colliding with an object in orbit. At the same time, the US was preparing for the imminent re-entry of Nasa’s first space station, Skylab. Interest in space junk and Kessler’s work spiked. In 1979, he got the nod from Nasa to establish an orbital-debris team and was allocated $70,000 of funding.
Since Kessler’s early efforts, a number of important steps have been taken to combat space junk. Nasa became the world’s first space agency to issue a set of orbital-debris mitigation guidelines in 1995, followed in 2002 by the Inter-Agency Space Debris Coordination Committee (IADC), which brought together 11 of the world’s space agencies. These documents described practices that could limit the build-up of orbital debris, by doing things like venting leftover fuel to prevent in-orbit explosions after a satellite ends its mission. The UN tweaked the IADC’s guidelines into its own voluntary set of rules, which were endorsed by the general assembly in 2007.
Then on 11th January 2007, the Chinese government successfully tested an anti-satellite missile on its own Fengyun-1C weather satellite, blowing it to bits and singlehandedly causing a 25 percent jump in the amount of trackable orbital debris. Two years later came the Iridium-Kosmos crash. “Everything that we had accomplished in terms of minimising the further accumulation of debris, it just totally undid it,” says Kessler.
Since the term Kessler syndrome was coined, it has at times been used to describe a doomsday scenario in which we could be completely cut off from space exploration by the impenetrable amount of junk flying over our heads.
Kessler believes that particular scenario is a long way off. “I use this analogy,” he says. “You can cross the street a lot safer than you can live on it. When you go to other planets, you’re just passing through our orbit. You spend such a short time that there’s not a serious chance of getting hit, like there is when you stay there for years.”
But what if that’s exactly what you’re doing?
“We’ve reached the point where we really have to do something,” ESA clean-space engineer Michel van Pelt tells me. “Satellites in lower orbits now have to manoeuvre about five times a year to avoid crashing with a piece of space debris. Twenty years ago, it was once or twice a year.”
A lot has changed in the wild black yonder over the past few decades. More countries have joined the select group that are able to put things into orbit and private companies have piled in too. In 2017 alone, a record 466 satellites were launched. That’s a lot when you consider that the estimated total number of satellites put into orbit since 1957 is 8,950.
But all this pales in comparison to what’s coming next, as a series of companies have announced their plans to put entire constellations of satellites into space.
On 23rd May 2019, SpaceX sent the first part of its Starlink constellation into orbit. Sixty 500-pound satellites were launched in one go from a Falcon 9 rocket that took off from Cape Canaveral in Florida. If SpaceX succeeds, these will form part of a network of nearly 12,000 satellites that will bring super-fast broadband to far-flung places where laying fibre-optic cable isn’t possible. But SpaceX CEO Elon Musk is not alone in his ambitions. Competition in the field of satellite-based internet is heating up. UK-based company OneWeb put the first six mini-fridge-sized satellites of its envisioned 650-satellite, high-speed-internet constellation into orbit in February. Amazon confirmed in April that it had filed for permission to launch 3,236 broadband internet satellites that will connect the world’s “unserved and underserved communities”.
Old satellites often fall apart… You have to actively take those big, broken satellites out of orbit”
Van Pelt echoes Kessler’s concerns that if nothing changes, entire orbits might eventually become unusable. “If we keep going like this for another 10 to 20 years, there’s a chance that the risk of your satellite being broken after you launch it just becomes too big… and that you’ll have to use less optimal orbits to prevent your satellite from getting destroyed within a few years,” he says.
There are two approaches to dealing with space debris: making sure new satellites don’t end up lingering in orbit in perpetuity and cleaning up the old stuff that’s already there.
The IADC guidelines stipulate that today’s satellites should have inbuilt mechanisms that will move them out of their orbit within 25 years of their mission ending. To do this, satellites that are relatively close to Earth can be instructed to use their last bit of fuel to thrust themselves back into the atmosphere where they will burn up. Satellites further out can fling themselves deeper into space into so-called ‘graveyard orbits’.
Sometimes, however, satellites fail, and are left looping uncontrollably around the planet: in April 2019, a $400-million satellite called Intelsat 29e suffered this fate after only three years of operation. And while some space agencies are committed to combating orbital debris, others are notably less bothered. On March 27th 2019, for example, India drew international condemnation when it flexed its military muscles by using an anti-satellite missile to shred a Microsat-R satellite, creating around 400 new pieces of orbital debris.
Even in a world in which technology never fails and nations stop voluntarily blowing their own satellites to smithereens in a fit of extraterrestrial sabre-rattling, orbital debris will continue to accumulate. “All the junk that’s already been launched stays there and old satellites often fall apart,” says van Pelt. “If you want to stabilise or improve the situation, you have to actively take those big, broken satellites out of orbit before they fall apart.”
Nobody wants to pay to clean up… We have to give space debris a new value”
In recent years, a number of inventive space rubbish-removal initiatives have been pitched. They include Sling-Sat, a proposed satellite that spins around in orbit, capturing debris at the ends of its arms, then flinging it back into the atmosphere. ESA, meanwhile, is planning to build an in-orbit servicing vehicle – a space “Swiss Army knife”, in its own words, that could perform a range of tasks including refuelling or refurbishing failing satellites as well as taking down derelict ones.
The space-junk removal race is currently being led by the University of Surrey. Its Space Centre in Guildford is heading a consortium of space companies and research institutions which in September 2018 became the first to snag a piece of rubbish from space. The RemoveDEBRIS satellite built by the consortium threw a net around a small cubesat it had deployed for testing purposes. In February 2019, RemoveDEBRIS bagged its second piece of space junk, successfully shooting a pen-sized titanium harpoon at an aluminium panel, then reeling it back in.
Then there’s Roosegaarde, with his plan to turn space debris into artificial shooting stars. “Nobody wants to pay to clean up,” he says. “With the current methods we’re not going to make it. We have to give [space debris] a new value.” Roosegaarde is currently raising funds to make his plan a reality. One of the places he’s turned to is the UAE. In 2014, Dubai spent $6 million on a single, Guinness World Record-shattering New Year’s pyrotechnics display.
“What I’m telling them is, instead of pouring all that money into tacky fireworks, put it towards Shooting Stars and help clean space,” says Roosegaarde.
Tussling over the scraps
When I put Roosegaarde’s idea to Joanne Gabrynowicz, a professor emerita of space law and the editor-in-chief of the Journal of Space Law, she buries her face in her hands. “There are such legal issues with that. You can’t just grab things [from space],” she says.
The single most important piece of space legislation is the Outer Space Treaty, sometimes referred to as the ‘constitution’ of outer space, signed in 1967. “At the time there were only two nations that could put anything in space and they were deadly adversaries – the Soviet Union and the US,” says Gabrynowicz. “Neither of them wanted the other to be able to grab their space objects and pull them apart to do reverse engineering.” The result: space objects belong in perpetuity to the states that launch them, even when they have long since been reduced to scrap metal. It’s not like the situation on the high seas, where anyone who helps rescue a stricken vessel is entitled to compensation. “There’s no salvage in space like there is in maritime law,” says Gabrynowicz.
She would like to see states agree on “a protocol of some kind” relating to plucking orbital debris from space. But there are challenges ahead. Satellites are still highly politically sensitive, says Gabrynowicz. “Space is a place where you have military as well as civilian assets all together. It’s always going to be seen through that dual lens. Even if the Cold War is over, nations don’t like other nations fooling around with their satellites.”
Roosegaarde is unfazed by Gabrynowicz’s criticism. “It’s not that complicated. All these pieces of space debris have a name and we know which country they belong to,” he says, gesturing at a still image visualising the locations of tracked, labelled pieces of orbital debris. “Here, this one I think is from China. So it’s just a matter of making a phone call,” he says with admirable optimism. He hopes that with the help of ESA his plans will become a reality within the next three to five years.
If Europe was without Facebook for four days because of space waste, this problem would be solved within a year”
“We can’t accept this [pollution of space]. It’s just sick that we’re not satisfied polluting our own planet, but continue into space,” he says. Asked if we’ll be able to fix the issue of space debris, Roosegaarde hesitates. “I don’t have an answer to that yet. I’m sure that if a load of satellites broke down and Europe was without Facebook for four days because of space waste, this problem would be solved within a year. But right now, I don’t see [others sharing] the sense of urgency.”
Kessler believes that orbital debris could become the next frontier in human pollution. “I see similarities between climate change and the orbital debris issue,” he says. “They’re both international, long-term issues that you need to address – and the longer you put it off the more expensive it’s going to be to fix it.”
There’s one big contrast, he adds, and it’s a cause for optimism: climate change is caused in large part by the fuel industry, but its results are not strongly felt by these companies, so they don’t have the motivation to fix it. “In the case of orbital debris, the people who are affected by it the most are the people who are in space,” says Kessler.
It’s a hopeful sentiment, but 28th June 2019 brought a reminder that even satellite engineers with the best intentions don’t always get it right. It was reported that communication had been lost with three of the 60 Starlink satellites launched by SpaceX the previous month. SpaceX said the failed trio would de-orbit “passively”, meaning atmospheric drag will eventually suck them back towards Earth where they will meet their fiery destiny. Because they are in low orbit, this will take a very short time in space terms. The three satellites will tumble uncontrollably around the planet for no more than five years – provided they don’t smash into something along the way.
We hope you enjoyed this sample feature from issue #35 of Delayed Gratification
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