Space debris: It's a situation that's just going to become worse.

 

Over 128 million objects larger than a millimetre are currently orbiting the earth, turning space around it into a junkyard. These objects range from inactive satellites to flakes of paint, but even a millimetre of cosmic junk travelling at extremely high speeds can be catastrophic to many satellites that connect us around the world; indeed, a fleck of pain was enough to damage a window on the International Space Station in 2016.

So, where does all this space debris originate from, why is it dangerous, and, most importantly, what are we doing about it? We've been sending satellites into space for nearly 60 years, and we've launched over 11 so far.

There are currently 140 satellites in earth's orbit, of which 3 370 are active and the rest are inactively floating in our orbit. The number of satellites has increased dramatically in recent years, with one 1283 satellites launched into lower earth orbit in 2020 alone, the highest number of satellite launches in a year to date. Now the low earth orbit is about to become even more crowded over the next few decades. SpaceX plans to launch a constellation of 42 000 satellites. Quipper, an Amazon project, is a web corporation. China's hong gyan and Canada's telesat are also preparing to launch tens of thousands All of this space traffic has the potential to be disastrous. In 1996, debris from a French rocket that had burst a decade previously struck and destroyed a French satellite. In 2009, a u.s. commercial satellite iradium 33 collided with a dormant russian communications satellite cosmos 2251 at a speed of 22 300 miles per hour.

With tens of thousands of satellites travelling around 17000 miles per hour, the chances of these satellites getting close to each other are a lot higher. Collisions between high-speed objects in orbit can create thousands of pieces of debris, which could result in a chain reaction where other spacecraft in low earth orbit are threatened. Donald kessler, a nasa scientist, coined the term "kessler syndrome" to characterise this event.

How can we stop this orbital junk-generating chain reaction from bringing space garbage down into the earth's atmosphere, where frictional heat from re-entry will burn it away?

In 2018, a satellite named remove debris was able to successfully create a net around a dummy spacecraft, modelling a method that could one day collect space-borne rubbish. In another technique, the satellite punctured a target panel that was roughly five feet away using its on-board harpoon.

 The European Space Agency has awarded a contract to a Swiss startup to retrieve a 220 pound piece of rocket debris that has been orbiting Earth since 2013 and is scheduled to re-enter the atmosphere in 2025. These methods are only useful for larger pieces of junk orbiting Earth; there is no way for us to pick up smaller pieces of debris such as paint and metal; all we can do is wait for them to re-enter the atmosphere.

If nothing changes and the amount of debris continues to grow, future space missions will be jeopardised. It's just a matter of time before more accidents occur, making cleaning up low earth orbit practically difficult without creative solutions. To watch and monitor the heavens, we'll have to rely on a network of ground and satellite-based observatories.