In May 2021, a routine inspection of the International Space Station (ISS) turned up a problem. Orbiting space junk had punctured a hole through the thermal protection which surrounded a 60-foot mechanical arm. A month earlier, four astronauts on their way to the ISS received a warning that they were in danger of a collision. Fortunately this was a false alarm, and the dangerous object passed by without causing a problem.
Both incidents, however, highlighted the growing risk posed by “space junk”, the detritus of more than 60 years of space exploration – from small pieces of satellites to objects the size of a doubledecker bus. Though the hole punctured through the ISS was just 0.2 inches wide, NASA is currently tracking around 23,000 objects which are the size of a tennis ball or larger. A collision with one of these larger objects could be catastrophic. In one scenario, posed by NASA scientist Donald J Kessler in the 1970s, these flying objects could smash into each other and create a cascading set of collisions in space. The 2013 film Gravity depicted such a nightmare.
Part of the problem is that we take our eyes off debris, says John Crassidis, the Moog professor of innovation at the University at Buffalo, who is working on how to better monitor space junk in order to improve safety. “We have telescopes and radars, and then we lose track of them,” he tells Spotlight. Without fully following the space junk, to predict what happens next scientists currently have to turn to Newton’s law of universal gravitation – a 1687 mathematical model developed 270 years before Sputnik, the first artificial earth satellite, was launched.
Crassidis’ work involves looking at how to calculate the shape of debris and how fast it rotates, as well as accounting for drag effects in lower orbits and any other factors that could affect how the space junk moves. “As we get better attributes, that may lead to better tracking and hopefully to better estimates of the probability of collisions and how to avoid collisions,” he explains.
Given the very high risk of collision from flying space junk, insurance is at a premium. Canopius is a firm that insures large geostationary orbit (GEO) satellites for an estimated $200m to $400m. Richard Parker, the joint head of space at the company, explains that GEO is the “prime real estate” for insurance, comprising higher value missions and much less debris from space junk. The problems, according to Parker, are mostly in Low Earth Orbit (LEO), where there’s been a steady growth in the numbers of satellites – and where there is much more space junk and a greater risk of something going wrong.
Space insurance covers “all perils” – in part because it’s very difficult to discover for certain what has caused a satellite to stop working: it could be a collision, a malfunction or a design flaw. The challenges involved in insuring these LEO missions are also about the business models at work. Only a fraction of companies developing LEO missions will make it into space and a further fraction will turn a profit. The spacecrafts involved in LEO missions are much smaller and might carry several satellites for different operators. As such, the insurance cover is still complex, but low value, ranging from a few thousand to a few million dollars per satellite. But, despite the lower coverage amount, the insurance policies would need to be as detailed as for a $400m mission because the risks are essentially the same.
The big companies involved in LEO missions sometimes choose to shoulder the risk themselves. Elon Musk’s StarLink network, which provides low-cost internet to remote locations, is one example. In StarLink’s case, Musk’s company SpaceX has deployed 3,000 satellites with a plan to put 12,000 in space (and maybe as many as 42,000) with a lifespan of five years. “If you have a spacecraft that fails, you don’t need to file an insurance claim because next month you’re going to launch another 50 spacecrafts and you’re just going to replace that one,” Parker says. However for many satellites they send into space, the companies face the same risks, and they absorb the financial loss as part of their business model.
Still, on a personal level Parker is concerned. “I, for one, am worried that we’re screwing up the space environment for the future,” he says. “I don’t want to encourage bad behaviour and want people to do the right thing.” For him that means no debris, good communication between satellite operators to avoid collisions, cooperating internationally, and being open to changes such as in-orbit servicing rather than disposable satellites. Under the 1967 Outer Space Treaty, nation states license companies to send satellites into orbit, but megaconstellations, such as StarLink, did not exist when the treaty was signed.
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Governments have already tried one satellite disposal approach: blowing them up. The US launched an “anti-satellite missile” as early as 1985, and in the last 15 years both Russia and China have used missiles to destroy satellites. However, this mostly turned a large hazard into thousands of smaller-sized hazards, which will orbit Earth for decades to come.
A number of companies and governments, including the UK, are now working on recovery and removal projects to clear up their space junk.
“Our focus is really on the engineering challenge of how we can clear up these orbits and make sure that we’re leaving this environment in a good state for future generations,” says Rory Holmes, the UK managing director at ClearSpace, a start-up headquartered in Switzerland. In 2019, the company won a contract from the European Space Agency to develop a debris removal mission, which it hopes to launch in 2026. The approach involves launching a space vehicle with a set of grabbing arms that can take a piece of space junk, pull it down, and release it so it will burn up in the atmosphere.
The engineering challenges of this are significant. “You’ve got to be able to rendezvous with the debris in orbit and approach it in a controlled manner. You have to image it, sense it, and inspect it. Then you need a robotic system that can grab hold of it and secure it,” Holmes says. Then, the debris is moved to the right place to dispose of it.
At a policy level, there’s the question of “who pays” for removal. “There’s no international mechanism to fund it, or to address the problem in general,” says Romain Buchs, a space policy analyst at ClearSpace. Buchs is pessimistic about the likelihood of a global consensus emerging to tackle the problem of space junk. He believes, however, that “likeminded nations” can start to address the problem together. The European Space Agency and the UK are both developing missions to deal with their own debris, and if more countries join them that could have an impact.
“That’s really what these missions will show,” says Holmes. “That this is feasible.” Crassidis welcomes the mission to test removal but is sceptical. “You can’t overcome the math,” he says. “Pushing, pulling, grabbing or harpooning space junk is incredibly complex and we’re only just starting to understand it.”
Focus needs to be on stopping people adding to space junk, he says, as we face a future crisis: “The younger generation is going to have to solve this problem.”
And if that doesn’t happen, this could make a Kessler scenario more likely and LEO missions uninsurable.
This article first appeared in the New Statesman’s Spotlight supplement. Click here for the full edition.
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