There’s space junk in the sky. And there’s space junk in the sea.
In the 60 years since people have been sending technology into space, the Earth’s orbit has started to resemble a cosmic landfill. According to the European Space Agency, there are 34,000 “debris objects” in orbit that are larger than 10 centimetres; 900,000 debris objects between one and 10 centimetres — and a staggering 128 million debris objects ranging from one millimetre to one centimetre in size. In all, more than 8,800 tonnes of objects are drifting in the inky darkness around our planet.
Most of the objects that fall from orbit are burnt up in the atmosphere. But very large bits of space tech, like the Soviet-era space station Mir — which was operational from 1986 to 2001 — meet a more watery grave. Some end up in the depths of the ocean — a carefully coordinated effort by global space agencies to ensure the safe re-entry of the items that aren’t incinerated as they are deorbited. Point Nemo, in the middle of the Pacific Ocean, is more than 1,600 kilometres from the nearest tiny island, located between New Zealand, Australia, Antarctica and the west coast of South America. Named after Jules Verne’s Captain Nemo in Twenty Thousand Leagues Under the Sea, Point Nemo was discovered by Canadian-Croatian geographer Hrvoje Lukatela in 1992. The zone is better known to space agencies as the South Pacific Ocean Uninhabited Area — and as a result of its remoteness, it has become a spacecraft cemetery.
Various satellites are monitoring the space debris situation, including the Canadian satellites Sapphire and NEOSSat. Michel Doyon, manager of flight and systems operations at the Canadian Space Agency manages the satellites under the control of the Canadian Space Agency. We spoke with Doyon about what space debris actually is and the role that Canada plays in the global effort to keep track of the dysfunctional human-made objects that orbit Earth.
On what space debris actually is
Space debris is a piece of an object — usually an artificial object — orbiting around the Earth. It can be a satellite that's not working anymore. It can be a piece of a rocket that was used to launch the satellite. It can be small bits and pieces like bolts or elements that were used to attach the satellite to the rocket — because when it was deployed, there's always a few bits and pieces being released.
On one hand, space is very empty by its nature. But there's lots of bits and pieces orbiting the earth. You could say there are roughly, give or take, about 23,000 objects orbiting around the earth. Those ones are monitored and measured 24 hours a day, seven days a week — and those objects are about the size of a baseball, like 10 centimeters or more. [Smaller] than that: there are hundreds of thousands of them.
On when space debris started to be a problem
What really drove all the activities and discussions on it were two accidents back in 2007 and 2009. 2007 was the Chinese anti-satellite test that generated almost 3,000 pieces of debris. They launched a rocket hitting their own satellite to make a demonstration of capability, but that created a lot of debris. That was among the most notable [incidents]. Then in 2009, there was a collision in space between Kosmos 2251 and Iridium 33 — that also created a lot of debris.
So it's fairly recent. But the issue is with space being more and more used, congested, contested, competed — to use some of the words that the US general used 10 years ago — the quantity of objects continues to grow. Only four years ago, there were about 1,200 satellites that were active; as of April 1 there's now like 2,600, more or less.
Between 1960 to 2000, we were hearing almost nothing about space debris and accidents in space. It was almost not discussed. It was, of course, monitored by space agencies or research agencies. Now, with more and more satellites being launched — there's one company launching about 60 satellites every two weeks — it creates an awful amount of new capabilities and new uses for space, but it becomes pretty crowded.
On global solutions
There's been the idea of well, should we have space traffic management, a bit like we have for air traffic, but for space? And this is discussed a lot — Canada is part of those discussions. The only challenge is there's a bunch of objects orbiting around the earth, traveling at about eight kilometers per second in all directions with little to no position or velocity control. So it's a complex thing to do.
The key message though is that no single nation can resolve this alone. Everybody needs to participate. There's a lot of discussions at the international level — the United Nations is one of them, and a lot of progress has been made. I was part of the group that generated the long term sustainability guidelines for outer space activities. It was a significant amount of work — it took about eight years — but it was officially sanctioned by the UN last year by more than 80 countries. So this is the next big step in the right direction to take for all space-faring nations.
On the environmental impact of space debris
Space is infinitely empty. Of course, the [less] consequences to the space environment we can make: for sure. But every nation today is very conscious of if they do something wrong today, well, it will impact themselves for future access — but also impact others. So I can be very positive: there was a wake up call and nations, including Canada, are aware and are working hard to find ways to avoid the debris, minimize the impact and have responsible behaviors in space.
On Canada's role in space debris management
On the technical aspect, Canada launched two satellites into space in 2013. One is named Sapphire — from the Department of National Defence — and one named NEOSSat, which was a collaboration between the Canadian Space Agency and Defence Research and Development Canada, the research arm of the Department of National Defence. The first one, Sapphire, owned by the DND, is one of Canada's contributions to the overall [space debris] effort. The space surveillance network is mainly driven by the U.S., so we're providing Sapphire as a sensor to help monitor and sense objects around the Earth. So it contributes to analyzing possible [collisions] or space debris issues.
NEOSSat is a telescope looking at the near earth objects that could approach Earth, as well as looking at the population of satellites or man-made objects orbiting around the earth. In simple terms, you put a telescope on a satellite, basically, and then you control your satellites from the ground to look at different places around Earth. So the telescope has proper lenses and so on to take multiple pictures of objects orbiting around the earth. With that, you can detect satellites’ trajectories — a portion of trajectories — of satellites. With that, you can estimate what the orbit is and then, using advanced mathematics or propagation algorithms, you can compute if one orbit will collide with another orbit at any given time. If there is a risk, then we can either plan an avoidance maneuver, or at least see it coming. Part of Canada's international outreach is that we’re helping other nations by providing calculations for them.
With everything Canada is doing with its excellence in space robotics, there was a lot of discussion and studies on on-orbit servicing. How could we use robotics to attach a robot to a satellite to go grab the large pieces of debris, basically, and collect them and bring them down to earth or burn them in the atmosphere?
So, you know, you can work at the technical level, but also at the policy and regulatory framework level. Canada is part of the IADC, the Inter Agency Space Debris Coordination Committee — we've adopted the IADC guidelines, which are a means to help prevent or reduce proliferation of debris. We're also part of the United Nation Committee on the Peaceful Uses of Outer Space. So these are international groups working on that. And one example within Canada: there is the Remote Sensing Space Systems Act, which requires a disposal plan before it issues a license to a remote sensing operator — this is to minimize debris or prevent debris creation. This is a really strong means of approaching the problem at least for the future.
On the space junk at the bottom of the sea
The idea is that Point Nemo [in the Pacific Ocean] is the largest circle of unpopulated area — it’s just water basically. So when objects return to Earth under a controlled entry, then engineers and technical teams try to make it fall in that area because it minimizes the risk of hitting populated areas. So that's where things end up there when they are under controlled reentry. But overall, you know, the Earth's atmosphere burns almost everything. What makes it through the atmosphere is like titanium tanks or a piece of metal that don't melt when reentering, or very large pieces like Tiangong that re-entered last year. And, you know, the earth is like 70 per cent water; 30 per cent land. So when you count the chances of being hit by a space object reentering Earth, the chances are much lower than a hole-in-one in golf. The atmosphere protects us a lot. But this Point Nemo area is the largest area of unpopulated land. So when people have the choice to minimize risk, then they try to make objects fall in that area. As far as I know, there's no Canadian objects that have reentered from space