On July 31, a component of a Chinese rocket weighing more than 20 tons fell to Earth, witnessing a meteor-like crater. A few days later, a fragment of the SpaceX spacecraft, Crew-1, was found stuck in the ground in Australia. The results of a study on the risk of human sacrifice by falling objects were published in the journal Nature Astronomy.
According to experts, microscopic celestial bodies are pouring down on Earth every day, and the combined weight is 40,000 tons per year. In addition, at the rate of once in 100 years, a celestial body with a size of several tens of meters breaks through the atmosphere and collides with the ground, creating a huge crater.
Artificial space debris, including the rocket booster that launched satellites, has recently become a new risk in place of these natural space debris. A research team from the University of British Columbia and the University of Victoria in Canada, through a paper published on July 11, 2022, modeled the behavior of rocket parts, orbits, and population density of the falling point in outer space, and added 30 years of satellite data to cause artificial space debris to fall to Earth. Predict the location or damage caused by it.
As a result, it was found that the probability of artificial space debris falling on latitudes such as Jakarta, Indonesia, Dhaka, Bangladesh and Lagos, Nigeria was three times higher than that of latitudes such as New York in the United States, Beijing in China, and Moscow in Russia. Through this, the research team points out that the risk of falling rockets is biased toward developing countries near the equator, not the rocket launch country.
The research team also calculated the risk of casualties that would cause damage to human life over a 10-year Locay re-entry into the atmosphere out of control. As a result, one drop is 10m2 Assuming that the area is littered with lethal debris, there is a 10% chance that there will be more than one casualty over the next 10 years. It’s small, but it’s going up.
As with natural space fragments, it has been thought that the risk of falling artificial space fragments is negligible, since most satellite and rocket fragments will burn upon re-entry even if they land on Earth. Therefore, previous research on space debris has focused primarily on the risk that a no longer functioning satellite might damage a still functioning satellite, i.e. cosmic collisions.
However, as the rocket launch business becomes more active, accidents between space and the ground are also increasing, such as China’s Longjing 5B rocket. Therefore, the team points out that the figure of 10% is a fairly conservative estimate. Ideas such as reusable rockets promoted by SpaceX and Blue Origin and capture robots being planned by the European Space Agency are being considered to increase this risk.
There are also international rules to curb space debris, such as the United Nations guidelines on reducing space debris. However, since the guidelines are guidelines only, there is no penalty. There are precedents, such as the Montreal Protocol, in which countries effectively implemented the protection of the ozone layer as a common goal of the world, but the reality is that these regulations are not discussed until they come into effect in the developed countries located in the north due to inter-Korean issues.
In the future, the research team will strengthen the international treaty on space debris in the year that should be commemorated as the 70th anniversary of the launch of the first artificial satellite in 2027, and if all UN member states can ratify it says it will be good. Related content this placecan be checked in