Every minute we are showered with debris from space , something of which we are hardly aware. Microscopic particles from asteroids and comets are deposited on the Earth’s surface adding about 40,000 tons of dust per year. Is it dangerous for us?
This space debris does not pose a risk to humans, but it does pose a risk to spacecraft, as happened recently with the James Webb telescope, and sometimes the samples arrive in the form of a meteorite. And maybe once every 100 years or so the meteorite makes it through the atmosphere and creates a crater.
The study published in Nature Astronomy has focused on man- made space debris , such as debris from rockets and satellites , how it can reach Earth in an uncontrolled way and how it can affect us.
The scientists mathematically analyzed the inclinations and orbits of the rocket pieces in space, as well as the population density below them. Satellite data from the last 30 years were also taken into account. In this way, they have estimated where rocket debris and other pieces of space debris land when they fall to Earth.
According to the study’s authors, the risk of space debris re-entering Earth in the next 10 years is small but significant. And if this happens, they will most likely end up in southern latitudes . The study estimated that rocket parts are about three times more likely to fall in the latitudes of Jakarta (Indonesia), Dhaka (Bangladesh) or Lagos (Nigeria) than in those of New York (United States), Beijing (China) or Moscow (Russia).
Regarding the risk of space debris killing a person, the researchers calculated that there is an average 10% chance of one or more casualties over the next decade, assuming each debris re-entry spreads deadly debris over an area. of 10 square meters.
Until now it has been thought that the probability of debris from satellites and rockets causing damage to the surface of our planet was negligible. These studies were carried out based on the risk that could arise from satellites that are out of service and that may affect the proper functioning of those that are active. Keep in mind that batteries and unused fuel can explode and create even more waste.
This study comes at a time when private initiative is increasingly interested in launching rockets into space . This increase in launches is likely to lead to an increase in the number of accidents, both in space and on Earth. A good example of this is the imminent fall of the remains of the Chinese Long March 5B rocket.
Taking into account the reality of the increase in launches, the scientists affirm in the study that the figure of 10% would be a conservative figure , come on, that they would be shooting low.
How could the uncontrolled entry of space debris be minimized?
There are technologies that allow to control the entry of waste, but its application is expensive. An example of this is making the fuel or batteries of spacecraft that are no longer in use spend instead of being stored. The orbit of a no longer functioning satellite can also be programmed to go into low Earth orbit , where it will burn up.
Another option is to make reusable rockets , like the ones Blue Origin is developing, that generate less waste. The remains of paint and metal shavings would return to Earth in a controlled manner.
The European Space Agency is planning a mission to try to capture and remove space debris using a four-armed robot. The UN, through its Office for Outer Space Affairs, issued in 2010 a series of guidelines for the mitigation of space debris, which was reinforced in 2018. However, as the authors of the new study point out, it is guidelines, not international law.
The study claims that advancing technologies and more thoughtful mission design would reduce the rate of uncontrolled re-entry of spacecraft debris, lowering the risk of danger worldwide. “Uncontrolled re-entries of rocket bodies constitute a problem of collective action; solutions exist, but all launching States must adopt them”, say the authors of the publication.
Referencia: Byers, M., Wright, E., Boley, A. et al. 2022. Unnecessary risks created by uncontrolled rocket reentries. Nature Astronomy. DOI: https://doi.org/10.1038/s41550-022-01718-8
