Belle Davenport
As the space industry evolves and grows, the possibilities are near endless. However, these technologies and systems are increasingly at risk of catastrophically colliding with space junk. According to NASA, millimetre-sized space junk represents the highest mission-ending risk to most robotic spacecraft operating in the low Earth orbit. The ramifications of such a collision could be monumental in its impact on the daily lives of people across the globe.
What is space junk?
Space junk or space debris refers to any human-made object that has been left in space. Space junk can refer to anything from dead satellites that have been left in orbit at the end of their mission, to small components of satellites that have catastrophically disintegrated, to tiny objects like paint flecks that have fallen off rockets. According to NASA, there are approximately 23,000 pieces of debris larger than 10 centimetres orbiting the earth, 500,000 pieces of debris larger than 1centimetre, and 100 million pieces of debris 1 millimetre or larger. A recent space debris collision in 2009 created 2300 pieces of large trackable debris as well as more, smaller pieces when a defunct Russian spacecraft collided with and destroyed a US Iridium commercial spacecraft. In that instance, the colliding space junk was very large. However, all debris, regardless of size, has the potential to cause damage to spacecraft as they travel at speeds of up to 17,500 miles per hour (28163.52 kilometres per hour). Several windows on NASA space shuttles have needed to be replaced due to damage from paint flecks.
The impact on our daily life
Many of the everyday products, technologies, and innovations that make up modern life come from the space sector. Experiments performed in space help us to better understand medical problems on Earth. Satellites provide important data on climate change, weather forecasting and natural disasters. They are essential infrastructure for global telecommunications. If a collision between space junk and critical space infrastructure such as satellites were to occur, we could lose access temporarily or semi-permanently to these amenities and features of modern life that we have grown to depend on. It is also possible for space junk to unexpectedly crash land on earth, as happened in the Snowy Mountains this July posing risk to people, the environment, and infrastructure.
Kessler Syndrome
Kessler syndrome is a phenomenon where the amount of space debris in orbit around earth gets to the point where an increase in collisions cascades, creating more and more space debris, or ‘debris clouds’. Because of the size and speed of space debris clouds, collisions between debris and infrastructure would grow exponentially, risking even high-value infrastructure, such as the Hubble Space Telescope, space shuttles, or the International Space Station.
Kessler syndrome is hypothesized as one of the near-future challenges that could pose a risk to the use of Space and the earth itself and there is evidence that the Kessler syndrome has already begun. The previously mentioned 2009 collision between the decommissioned Russian satellite and American Iridium spacecraft is an oft-cited example. As the space industry evolves and grows, the possibilities for technological growth are near endless. We expect our dependency on the space industry and technology will only grow. It is therefore important that the issue of space junk is addressed before it is too late.
How is the issue of space junk being addressed?
There are intergovernmental and commercial efforts underway to fix the issue of space debris. Many scientists and engineers are working on the challenge of identifying and removing space debris from orbit, with proposed techniques spanning from “old-fashioned” methods, such as the use of harpoons and nets to remove larger pieces of debris, to technologically advanced uses of AI.
Artificial intelligence (AI) can be used to create a system of satellites smarter than their predecessors, able to avoid debris and remain whole and operational. Various Australian space industry partners including Swinburne University of Technology, EY, the CSIRO, Data 61, and the Australian space industry consortium SmartSat CRC are working to develop an industry standard for AI in space, so that systems from different owners can operate in the same space, literally.
However, from a governance and policy perspective, there is more that needs to be done in Australia regarding space debris. Australia has agreed to prioritise the debris mitigation guidelines specified by the Committee of the Peaceful Uses of Outer Space (COPUOS), a United Nations body. However, there is no specific national policy toward space debris creation or the mitigation of existing debris. Developing a national policy
reducing space debris creation will be essential for ensuring that public and private actors in the Australian space sector are contributing positively to resolving the challenge of space debris rather than actively contributing to the problem.
Already, space experts estimate there are 12,000 pieces of debris 10 centimetres long and larger that we can track, but nearly one million from one to 10cm in size, and over 100 million pieces smaller than a centimetre that we simply can’t see coming.
Although we can’t see it from Earth, space debris poses a significant risk to our way of life. There are risks to our long-term use of space too; some low-Earth orbits have already accumulated critical amounts of debris. If space debris continues to grow at the current rate, it is possible that other orbits also become overwhelmed to the extent that space becomes unusable. Addressing the challenge that space debris poses to our collective way of life requires solutions from governments alongside industry, leading scientists, engineers and technologists.
Belle Davenport studies International Relations and Peace and Conflict Studies at the University of Queensland. Her Master’s thesis is exploring the challenges of governing permanent settlements in Space.