Space Junk

Sputnik 1 was launched into low Earth orbit (LEO) by the Soviet Union in October of 1957—just over 60 years ago. Since then, about 7,000 other spacecraft have been sent into orbit.

Seems like a lot, right? Well, it isn’t. Not even close.

These days, companies like SpaceX, OneWeb and Boeing are working toward launching “mega constellations” into orbit. Some 10,000 satellites will be added into the mix, more than doubling the number of satellites launched since the heady days of Sputnik 1.

Most of these constellations will be sent into LEO orbit. And that’s the riskiest orbit you’ll find, because it’s the region surrounding the Earth that is most densely populated by space debris.

The debris consists primarily of man-made objects—bits of old satellites and spent rocket stages. Some pieces of debris are quite large, and others are practically invisible. But they don’t need to be big to have a huge impact.

Last summer, a pebble of debris no more than a few millimetres in size collided with a German satellite. That tiny fleck of space junk left a crater 40 centimetres wide, the satellite’s power was reduced and it was knocked into a different orbit.

That’s what happens when your spacecraft gets hit by a tiny rock travelling in kilometres per second. Of course, it gets much worse if the debris that hits your satellite is larger.

There’s a lot of space junk that’s bigger than a few millimetres, and it’s concentrated in LEO orbit— anywhere from 200 to 2,000 kilometres above the planet’s surface.

“There are approximately 23,000 objects larger than a baseball—about 10 centimetres—that are tracked 24/7, all the time,” explains Michel Doyon, Canada Space Agency’s manager of flight operations. “The baseball-size debris travels at 7.5 kilometres per second. If you get hit by that, it essentially means the destruction of your space asset.”

Moving from GEO to LEO

Not all satellites are insured, although commercial ones commonly are. To date, most commercial satellites have been launched into geostationary orbit (GEO)—more than 35,000 kilometres above the planet’s surface—where space debris is far less concentrated.

However, with mega constellations being launched into LEO orbit, many in the insurance industry are becoming increasingly concerned about the threat of space debris.

“What we’re seeing is an evolution of the market towards low Earth orbit,” explains Peter Elson, chief operating officer of JTL Specialty’s aerospace division. “The commercial exploitation of space looks like it’s shifting from GEO to LEO. To that extent, we’re going to see more insurance activity in LEO than we have in the past.”

Clive Smith, the space business unit leader for Aon’s International Space Brokers, says that most of the satellites insured through Aon have so far been in geostationary orbit.

“The probability of having an impact in geostationary orbit is very limited,” Smith says. “But obviously, the probabilities of having an impact [in LEO orbit] are much greater because it’s more populated and the volumes we are talking about—scientifically, there’s a much greater probability there. It’s a different kind of environment from a space insurance point of view.”

Of course, space junk is only one of the many threats a satellite faces, and so far, it hasn’t been the most serious.

“To date, there have been a limited number of incidents involving debris,” Elson says. “I don’t recall any major insurance claims.”

A possible reason for this is that space debris must be about the size of a golf ball for it to be tracked. Particles smaller than that may, indeed, be causing damage to satellites—it’s just hard to know for sure.

“We don’t know, but it’s possible there may have been claims that the market has paid, but they simply haven’t been attributed to debris because of the lack of visibility on the root cause of a loss,” Elson says.

Typically, the greatest threats faced by satellites have been surviving a launch and the harsh conditions of space, Elson notes.

“In the context of a market which is inherently high-risk, where the process of launching a satellite into orbit on a rocket is extremely risky, where, historically— although there’s been improvement recently— around one in seven or eight missions fail, a risk of debris, in comparison, has been a relatively small part of insurers’ risk modelling approach,” he says.

But that could soon change.

“The advent of these huge numbers of satellites going into low Earth orbit, where the risk is greatest, clearly does further increase the risk,” Elson says. “There are some schools of thought that suggest the numbers, when you translate them into mathematical probability, don’t necessarily make a huge difference to the risk. But I would describe it this way: there’s already enough out there that we’re at a critical stage.”

Where did all this junk come from?

Two major incidents led to the proliferation of debris in low Earth orbit.

The first, China’s infamous anti-satellite missile test, occurred in 2007, when the country launched a missile into orbit to blast a weather satellite into smithereens—about 3,000 smithereens, to be precise.

The second event occurred in 2009, when Iridium 33, part of the Iridium satellite constellation, collided with a defunct Russian satellite, Kosmos 2251. This resulted in another 3,000 bits of space debris, give or take.

“The primary worry is that even the smallest pieces of debris are travelling incredibly fast and have a lot of energy,” says Ben Spain, an account manager with JLT Specialty’s aerospace division. “Even something the size of a pinhead could potentially cause a lot of damage if it impacts with a satellite.”

And that damage could lead to further debris, which would make it even riskier to send a spacecraft into orbit. This scenario was first envisioned in 1978 by NASA scientist Donald Kessler, who predicted that an increase in debris could lead to a cascade reaction of collisions—referred to as the Kessler syndrome.

“Even something the size of a pinhead could potentially cause a lot of damage if it impacts with a satellite.”

Theoretically, it could take just one impact to set off a chain reaction, leading to potentially disastrous consequences. But it’s unlikely we’ll see an increase in premiums until the market starts incurring losses directly related to space debris.

“At the moment, although [space debris] is much talked about when we go to insurance conferences, it is not something that is specifically targeted by most underwriters as a big risk factor,” Spain says.

But Spain predicts that in five or 10 years—once the mega constellations have been sent into orbit—insurers could have a very different view of the threat.

Mitigating the risk of collisions

The CSA receives conjunction alerts when tracked pieces of debris are on a potential collision course with a satellite, giving satellite operators the option to move their spacecraft out of harm’s way.

“Then you get a few measurements and you have to decide what you’re going to do,” Doyon explains. “Do you avoid the debris, or do you judge that the risk is not significant enough?”

A satellite’s thrusters can be engaged to move it out of the danger zone or, if the risk is deemed minimal, the satellite can remain in place.

“All the geostationary satellites have thrusters and a propulsion system, so if there’s something big coming towards them they can maneuver,” Smith says. “The low Earth orbit ones also have thrusters, but they are less responsive at low Earth orbit because the energy requirements are a lot more.”

When a satellite reaches the end of its life, it can be removed from orbit to ensure it doesn’t pose a threat to other spacecraft.

Satellites in LEO orbit can be propelled into the Earth’s atmosphere, where they disintegrate on re-entry. Geostationary satellites can be sent out to a “graveyard orbit,” far enough away from Earth that they won’t pose a threat to other spacecraft.

And then there’s the matter of what to do with the debris that is currently encircling the Earth. One idea is to use active debris removal (ADR).

“You would launch a space system that would go and grab some of the larger [pieces of] space debris and deorbit them,” Doyon explains. “There is one school of thought that says we should try to locate the bigger masses, like a piece of a rocket. These things are huge, so if something were to collide with them, it could create a lot more debris.”

To date, the concept of ADR hasn’t been put into practice, although it will be tested this year when Surrey Satellite Technology Ltd.’s (SSTL) RemoveDEBRIS mission is launched.

The RemoveDEBRIS spacecraft will be sent to the International Space Station, where it will attempt to de-orbit space junk using harpoons and nets. This could provide a relatively low-tech solution to the problem of space debris—but, at this stage, it would be the only solution available.

Perhaps the biggest obstacle to solving the space junk problem is money. The SSTL project is funded by the European Commission, but it’s just a proof of concept.

“The number of satellites you would need to put into orbit to start to clear up the problem would require a huge amount of centralized funding from someone, and no one as yet has put their hand up to bear the cost of that,” Elson says.

And until space debris can be contained, it will remain a significant concern for the industry.

“It is sufficiently serious to have all space-faring nations meeting at the international level regularly,” Doyon says. “The whole space community is working hard to find guidelines and look at different possibilities of how to prevent the proliferation of debris, how to maintain the access to space and how to protect yourself from the threat.”

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Copyright © 2018 Transcontinental Media G.P. This article first appeared in the May edition of Canadian Insurance Top Broker magazine

This story was originally published by Canadian Insurance Top Broker.