Australian researchers aim to clean up the orbiting space junkyard to avoid a chain reaction of self-sustaining debris collisions involving lasers and artificial intelligence.
Space debris expert Don Kessler of the National Aeronautics and Space Administration (NASA) was noted by The Age as the first to note that space is in danger of becoming inaccessible to Earth. Kessler observed that once the amount of space debris in orbit reaches a critical point, inevitable collisions will occur. These collisions will lead to more debris, which will create a chain reaction of cascading collisions that cannot be avoided. This phenomenon is called Kessler syndrome.
Thousands of rockets, satellites and various objects have been launched into space since the 1950s, and the amount is growing exponentially. This year alone, SpaceX set the record for the number of satellites sent into space on one rocket, launching 143 satellites on the Falcon 9.
According to estimates by the US Department of Defense and NASA, there are currently around 23,000 pieces of space junk larger than a softball in Earth orbit. Accompanying this debris is half a million pieces of debris the size of a marble or larger and about 100 million pieces that are one millimeter (about 0.04 inch) or larger.
However, as the world relies on satellite technology for navigation, weather forecasting and communications, governments and agencies cannot stop sending satellites into orbit.
Many scientists are working to identify and collect space debris in Earth orbit, some using nautical techniques such as nets and harpoons to fish out the larger debris fragments. However, much of the debris is difficult for astronomers to see because Earth has what is known as a shimmering atmosphere that can hide particularly small pieces of debris.
“The ‘shimmering’ of the atmosphere is caused by the turbulence, or fluctuations, in the air above us,” Swinburne University of Technology postdoctoral researcher Sara Webb said in an email to The Epoch Times.
“Our atmosphere is dense and constantly moving due to the physics of heat and gases. It’s what makes the stars twinkle, that light is constantly being refracted and reflected in different directions.”
Overcoming the atmosphere with lasers
To counteract the shimmering atmosphere, scientists are using Electro Optic Systems (EOS) technology, in which a laser attached to a telescope on Mount Stromlo in Canberra, Australia, fires laser light into the sky. The shimmering effect of the atmosphere distorts the laser light, giving astronomers a chance to “see” the smaller space junk.
“You can think of adaptive optics as trying to mimic the movements of the air above us toward the mirror that reflects the light,” Webb said.
“We’re trying to correct some of the refraction to sharpen and focus the light passing through the atmosphere.”
“By improving something we call ‘seeing’, we can resolve smaller objects like space debris. Otherwise they would be too faint and their light too diffuse for us to identify,” she said.
Refined perception of these objects is enabling Australian astronomers to guide satellites, astronauts and government and private agency spacecraft away from the debris.
Another approach to removing smaller pieces of debris is to shoot a high power laser into the atmosphere. The pressure of the laser forces the space junk to lower its orbit towards Earth, where it will then safely burn up as it enters the upper atmosphere.
“It’s a so-called ‘laser broom’ that can remove space debris. That means it helps loosen/shred material, and thereby gives a little boost to the force of the material moving away from the object,” Webb said.
“It helps the debris slow down enough to fall deeper to earth and burn up on entry.”
Australia plays an essential role in collecting space debris as it has space technologies that few countries in the southern hemisphere possess to monitor the vast skies.
Could artificial intelligence provide better guidance through space?
However, with the amount of debris and satellites in space growing exponentially, relying on human guidance could present problems as errors can occur. Scientists therefore postulate that artificial intelligence (AI) guidance systems could be a better approach.
A new suite of smarter satellites, led by AI scientists, could avoid space debris without human intervention while remaining complete and operational. The risk with AI, however, is that the guided satellites can’t communicate with each other, which could trigger the cascading collisions that humans want to avoid.
If a satellite moves into the path of a second satellite to avoid debris, the second satellite may move into the path of a third, and so on.
A partnership project called “Responsible AI in Space” has been launched to establish an industry standard for AI satellites in outside world applications. The establishment of an industry standard should ensure that AI satellites across different authorities do not fulfill the above prophecy.
The partnership consists of space scientists, legal and policy experts, governments, the space industry and practitioners of AI security – a field focused on maximizing the benefits of AI and minimizing its dangers. The team will develop a framework to assess the trustworthiness of AI systems in space for companies, satellite operators, regulators and insurers.