10% chance of space junk falling on a person's head, small but dangerous rate

Although the possibility of bird droppings hitting your head is higher than the risk of space junk falling, it's not impossible, there have even been cases of injuries and property damage because of space junk.

As humans launch more and more satellites, rockets and probes into space, we are more and more exposed to dangers from space junk.

Every minute of every day, debris from space is always entering the Earth's atmosphere.

A new study, recently published in the journal Nature Astronomy, estimates the chances of a person being hit by a falling rocket component within the next 10 years.

Every minute of every day, debris from space is always entering the Earth's atmosphere. It is a danger of which we are barely aware. Microscopic particles from asteroids and comets pass through the atmosphere and fall to the Earth's surface in ways we don't expect. It also generates about 40,000 tons of dust a year.

But the problem with humans is space junk, debris from satellites, rockets after the end of the mission can fall back into the atmosphere. They can also be broken by collisions with asteroids or meteorites. These are all large objects and are located very close to the Earth's atmosphere, so sometimes cannot be completely destroyed by friction when falling.

Using mathematical models of the inclination and trajectories of rocket components in space, their densities, and 30 years' worth of satellite data, the authors estimated the location of the rocket debris. and other pieces of space junk landed as they fell back to Earth.

The study estimated the likelihood of the missile body falling at latitudes of Jakarta in Indonesia, Dhaka in Bangladesh, or Lagos in Nigeria about three times higher than New York in the US, Beijing in China or Moscow. -va in Russia.

Debris from satellites and rockets that can cause harm on the Earth's surface is negligible.

The authors also calculated "casualty expectations," the risk to human life over the next decade as a result of uncontrolled rocket reuse. Assuming each fall back to Earth, the debris scatters potentially lethal debris over an area of ​​10 square metres, there is an average 10% chance of one or more casualties over the next decade.

So far, the possibility that debris from satellites and rockets could cause harm on the Earth's surface (or in the atmosphere for air traffic) is negligible.

But as the number of space companies involved in the business and launching of rockets increases, it is likely that the number of accidents caused by space junk will increase, both in space and on Earth. The most obvious example is the increase in the number of debris drops after the Long March 5B rocket launch on inhabited locations.

The study cautions that the 10% figure is a conservative estimate.

Do people have any measures to prevent?

There are a variety of technologies that help humans control the re-entry of debris, but they are expensive. For example, spacecraft can be "passivated", whereby unused energy (such as fuel or batteries) will be used instead of stored when the spacecraft's lifetime is over. end.

The choice of orbit for a satellite can also reduce the chance of debris generation. A defunct satellite can be programmed to move into low Earth orbit and burn up before falling to the surface.

There are also reusable rocket launch attempts, such as SpaceX which have proven successful and safe. Blue Origin is also growing. They produce a lot less debris, although there will be some debris from paint and metal when they return to Earth.

Reusable rockets create a lot less debris

The European Space Agency is planning a mission to try to capture and remove space debris with a special robot. The United Nations through the Office of Outer Space Affairs issued the Space Debris Reduction Guidelines in 2010 and were supplemented in 2018.

However, these are guidelines, not international law, and do not give specific details on how to implement or control mitigation activities.

The team, on the other hand, argues that only by adopting the most advanced technologies and better planning the missions will reduce the incidence of uncontrolled falls. Above all, there needs to be a common solution for all countries to control missile body relaunch.

In five years, it will be 70 years from the date of the first satellite launch into space. A great celebration if it could be marked by an international treaty that mandates the control of space debris and is ratified by the United Nations. Of course every country would benefit from the security of such a treaty.