Space debris: is the airspace around Earth cluttered with junk, and is there a sustainable method of getting rid of it?

Satellites hover just above Earth providing us with a stream of constant information, amplifying how we live and communicate with each other. However, this advancement in humankind has also left us completely dependent on them. Satellites are used to track weather, to observe Earth and to see climate change in real-time. The images also allow local authorities to plan and monitor hurricanes to help provide health and relief from natural disasters. 

Satellites also provide vital communications and precise timings for logistic chains and supply chains around the world, as well as financial transactions made in microseconds. Of course, we also are reliant on using data to take us from A to B when we get lost around big cities, or meander through the countryside - all information provided by satellites. However, our satellites are under threat. There are around 8,800 active satellites but around 35,000 pieces of debris, Ray Fielding, head of sustainability at the UK Space Agency told Nationalworld. 

The pieces of debris are known as space junk that "have no real purpose." He said: "When we first started with our space adventures, we had no real thoughts about some of the effects of our activities which might create secondary effects. The purpose was to get to the moon or send a probe to Mars, but there was no thought about what might happen to the secondary items such as spent rocket bodies, or defunct satellites."

The number, 35,000, refers to pieces of unused satellites, broken satellites, defunct satellites, rocket bodies or bits where satellites have collided and created debris - which are the larger pieces. Smaller debris underneath 10 centimetres can still be dangerous, and these are numbered at around a million pieces floating around the Earth, travelling at 17 and a half thousand miles an hour. 

When space junk collides with other objects, it can cause damage, and Fielding explains there are several satellites which have just suddenly stopped working, which they think may be due to a space junk collision. "We're creating almost like a cloud of debris around the Earth." 

Fielding says. The impact of space debris falling back to Earth can have a ripple effect and he gave an example where the Spanish airspace was closed in December 2022, because a piece of space debris came down through the airspace. No one knew what the impact of that would have been - for example, it may have hit a plane. As a safety and priority, they shut down the airspace which cost millions of euros in economic effect.

Other than the danger of space debris coming down and hurting people or damaging properties, we're running out of space in the usable satellite sites. Worst case scenario, we'll lose access to get into the atmosphere and remove excess debris. 

So what can be done about it? The UK Space Agency is investing in more sustainable satellite operations. Currently, satellites can stay in orbit for 25 years after they go dead, but a recent US law has changed it to five after fining network company DISH for failing to remove their satellites properly. Right now, the UK has a fairly good idea of where the large pieces of space debris are, and there is still a large area where rockets have access to outer space, but this could all change in around six years when space debris can accumulate to such a point all access to space would be gone forever. 

Fielding says, to reduce the chances of that happening, is to prevent the problem from occurring in the first place. "The best way to prevent space junk is to not create it in the first place" he says. SpaceX does "wonderful" ways of practising sustainable rocket launches, by deorbiting rocket bodies during the launch procedure - as a few rockets belonging to the private American space company are reusable, which prevents the problem from growing in the first place. 

Fielding emphasises that it is important to find a balance between balancing economic growth, which is crucial, and sensible regulation. To help with this issue, the UK Space Agency is treating some of the space junk in a remedial effect, through a national Debris Removal mission. The idea is to launch a spacecraft which will capture two defunct satellites, and dock with them to remove them from orbit, reducing the number of satellites in orbit. The defunct satellites will be deorbited - where they will burn up in Earth's atmosphere - leaving no debris behind. 

The probe will then remain in orbit, to be refuelled and reused to remove more default satellites from orbit, in return reducing the amount of space junk in the atmosphere. Fielding says: "Throwaway item culture is something people realise isn't a sustainable model for the Earth's environment and certainly a thing we feel is not sustainable for space either. So these two technology missions which we're currently investing in the development of, will help in some way to solving these problems."