The probability of someone being killed by space debris falling from the sky may seem very small. So far, no one has died, although there have been cases of injuries and property damage.
But as the number of satellites, rockets, and probes launched into space grows, it’s worth considering whether we should take the risks more seriously.
That is why a new study published in the journal Nature Astronomy sought to estimate the probability of casualties from falling parts of missiles in the next 10 years.
And every minute of every day, debris from space rains down on us, a danger we barely notice. Microscopic particles from asteroids and comets pass through the atmosphere and settle on Earth’s surface undetected, adding up to 40,000 metric tons of dust each year.
While this is not an issue for us, such debris can damage spacecraft, as was recently reported for the James Webb Space Telescope.
Occasionally a larger specimen arrives in the form of a meteorite, and perhaps every 100 years the object within tens of meters manages to bypass the atmosphere to dig a hole in the ground.
Fortunately, objects many kilometers across rarely reach the surface and cause death and destruction, as evidenced by the extinction of the dinosaurs. These are examples of natural space debris whose uncontrolled arrival is unpredictable and spread almost evenly across the globe.
However, the new study looks at uncontrolled access to artificial space debris, such as used rocket stages associated with launching rockets and satellites.
Using mathematical modeling of the inclinations and trajectories of rocket fragments in space and the population density below, as well as the past 30 years of satellite data, the researchers predicted where rocket debris and other unwanted Earth fragments are in space when they fall to Earth. .
They found that there was a small but significant risk of reintroducing the components in the next decade. However, it is more likely to occur in southern latitudes than northern latitudes.
In fact, the study estimates that missiles are almost three times more likely to land at the latitude of Jakarta in Indonesia, Dhaka in Bangladesh or Lagos in Nigeria than New York in the United States, Beijing or Moscow in China. In Russia.
The scientists also calculated the “expectation of loss” – the risk to human life – over the next ten years as a result of the return of uncontrolled missiles.
They found that assuming each return spread deadly debris over an area of 10 square meters, there was an average 10 percent chance of casualties over the next ten years.
Until now, the possibility of damaging the Earth’s surface (or air traffic) from debris from satellites and missiles has been excluded.
Most of these studies of space debris have focused on the hazards posed by orbiting satellites that may impede the safe operation of orbiting satellites. Unused fuel and batteries also lead to orbital explosions that generate additional waste.
But as the number of launches increases in the missile launch business and the transition from government to private enterprise, the number of accidents in space or on Earth is likely to increase as well.
But the new study says the 10 percent chance is still a conservative estimate.
What can he do?
There are some methods that make it absolutely possible to completely control the entry of debris, but they are very expensive to implement. For example, a spacecraft may be ‘passivated’ (rested) where unused energy (such as fuel or batteries) is spent rather than stored after the spacecraft expires.
The choice of satellite orbit can also reduce the possibility of debris. The obsolete satellite could be programmed to move into low Earth orbit, where it would burn up.
There are also attempts to launch reusable rockets similar to those made by SpaceX and Blue Origin.
While the European Space Agency is planning a mission to try to retrieve and remove space debris with a four-armed robot, few agencies are taking the risks seriously.
The United Nations, through the Office of Outer Space Affairs, released a set of space debris reduction guidelines in 2010, which were strengthened in 2018. However, as the authors behind the new study point out, it are guidelines rather than international law. does not provide details on how reduction activities will be implemented or controlled.
The study argues that advancing technologies and more careful mission design will reduce the rate of uncontrolled re-entry of spacecraft debris and reduce risks worldwide.
It is noteworthy that 70 years have passed since the first satellite was launched into space in five years.
source: phys.org
Source: Arabic RT
