The catalogue is the most widely used public listing available, but it lacks some satellites that countries — including the United States, China and Russia — have not acknowledged publicly. In part because of this lack of transparency, other nations also track space objects, and some private companies maintain commercially available catalogues. Rather than this patchwork of incomplete sources, what the world needs is a unified system of space traffic management.
Through this, spacefaring nations and companies could agree to share more of their tracking data and cooperate to make space safer. This might require the creation of a new global regime, such as an international convention, through which rules and technical standards could be organized. One analogy is the International Telecommunication Union, the United Nations agency that coordinates global telecommunications issues such as who can transmit in which parts of the radio spectrum.
For it to succeed, questions of safety such as avoiding smashing up a satellite will need to be disentangled from questions of security such as whether that satellite is spying on another nation so that countries can be assured that participating in such an effort would not compromise national security.
Countries could, for instance, share information about the location of a satellite without sharing details of its capabilities or purpose for being in space. One near-term move that would help would be for the United States to complete a planned shift of responsibility for the Space-Track.
Because this catalogue has historically been the most widely used around the world, shifting it to a civilian agency could start to defuse geopolitical tensions and so improve global efforts to manage space debris. It might one day feed into a global space-traffic agreement between nations; even the nascent space superpower China would have a big incentive to participate, despite rivalries with the United States.
The transition was called for in a US presidential directive that recognizes that companies are taking over from national governments as the dominant players in space, but it has yet to occur, in part because Congress has not allocated the necessary funds. On 25 August, the UN Committee on the Peaceful Uses of Outer Space will meet to discuss a range of topics related to international cooperation in space. The UN is the right forum through which spacefaring nations can work together to establish norms for responsible space behaviour, and that should include how the world can track objects to make space safer.
It should continue recent work it has been doing emphasizing space as a secure and sustainable environment, which at least brings countries such as the United States and China into the same conversation. Basic research has a role, too: innovations such as techniques to track and display the locations of orbiting objects in real time, and artificial intelligence to help automate debris-avoidance manoeuvres, could bolster any global effort to monitor and regulate space.
If governments and companies around the world do not take urgent action to work together to make space safer, they will one day face a catastrophic collision that knocks out one or more satellites key to their safety, economic well-being or both.
It successfully completed its mission later that year and has floated dormant ever since. The second satellite has a slightly more intriguing story. Known as GGSE-4 , it is a formerly secret government satellite launched in It was part of a much larger project to capture radar emissions from the Soviet Union. This particular satellite also contained an experiment to explore ways to stabilise satellites using gravity. Weighing in at 83kg, it is much smaller than IRAS, but it has a very unusual and unfortunate shape.
It has an 18m protruding arm with a weight on the end, thus making it a much larger target. Almost 24 hours later, LeoLabs tweeted again. It downgraded the chance of a collision to 1 in 1,, and revised the predicted passing distance between the satellites to m.
Although still closer than usual, this was a decidedly smaller risk. But less than 15 hours after that, the company tweeted yet again , raising the probability of collision back to 1 in , and then to a very alarming 1 in 20 after learning about the shape of GGSE The good news is that the two satellites appear to have missed one another.
Although there were a handful of eyewitness accounts of the IRAS satellite appearing to pass unharmed through the predicted point of impact, it can still take a few hours for scientists to confirm that a collision did not take place. LeoLabs has since confirmed it has not detected any new space debris. That requires us to be extremely conservative, especially given the cost and importance of most active satellites, and the dramatic consequences of high-speed collisions.
The tracking of objects in space is often called Space Situational Awareness , and it is a very difficult task. One of the best methods is radar, which is expensive to build and operate. The ISS has had to maneuver out of the way of space debris to avoid damage on three occasions this year, including a near miss less than a month ago. The debris field from a collision of this scale would have posed a danger to any craft passing through, including satellites on their way up to a higher geosynchronous orbit about 22, miles above Earth , or any satellites above that are being deorbited into the atmosphere to burn up.
The space around Earth is getting more and more crowded. In all, some 29, human-made objects larger than 3. Demand for more and better internet access is steadily increasing the population of satellites. For example, private firm SpaceX has launched several hundred of its Starlink communication satellites into low-Earth orbit, and thousands more are planned.
One of the worst space equipment collisions happened in February , when the operational Iridium 33 communications satellite collided with a defunct Russian military satellite, Kosmos , above Siberia. The crash unleashed some 1, pieces of space debris that are still being tracked, and it increased the total amount of debris in low-Earth orbit by about 10 percent, McDowell says. Unless we develop a better system for avoiding collisions, cascading space junk could limit access to orbit.
To date, most of the data about the trajectories of these objects has come from the U. The Space Surveillance Network, part of the U.
Space Force , uses a global array of telescopes to track everything larger than a grapefruit. Ceperley points out that most of the U. The company also operates stations in Alaska and Texas. The Department of Defense provides advance warning to NASA, as well as to companies and countries around the world, if it detects that spacecraft are in danger of being hit. As more satellites are launched to space, more close calls and, ultimately, more collisions, are inevitable, Ceperley says.
All rights reserved. Litter in space The space around Earth is getting more and more crowded. Dan Falk danfalk is a science journalist based in Toronto.
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