When you look at the sky at night, you might see the moon and the stars depending on where you are. But there is a lot more out there in space, some of it is starting to be noticeable. Astronomers may be worried about satellites lighting up the sky, but they’re not just impacting nighttime observations of the universe, they’re contributing to a growing problem. Space is polluted with debris, known as space junk, it’s any man made object that no longer serves a purpose. Ever since the space age began when the Soviet Union launched the first satellite into orbit, the Sputnik one in 1957 debris has built up. Liftoff of space shuttle appliions, some amount is created every time rockets are launched when certain stages of the rocket separate from the main vessel, the big pieces that fall off might burn up in the atmosphere and do not become debris, but tiny fragments that don’t burn up like flakes of paint, end up as junk.
The main cause of debris however is satellite collisions and explosions in 2009, a privately owned American satellite and a dead Russian military satellite accidentally colliding over 2000 pieces of debris, when China deliberately blew up one of its own weather satellites as part of an anti satellite missile test in 2007, it created a cloud of more than 3000 pieces of debris, the most ever tracked liftoff. The problem is now back in the spotlight as SpaceX looks to launch thousands of satellites for its internet service, starlink.
Only 9000 satellites have ever been put in orbit in all of history SpaceX plans on launching as many as 42,000 as creating a space that is going to create issues, there are concerns starlink will add to the 8000 metric tonnes of debris already in Earth’s orbit, that is just under the weight of the Eiffel Tower. Most of the debris in space sits in what’s called low Earth orbit in orbit that is relatively close to the earth surface less than 1200 miles or 2000 kilometres away fragments are usually quite small, those that measure larger than 10 centimetres make up over 23,000 pieces, between one to 10 centimetres about 500,000 and in total pieces larger than one millimetre exceed 100, million, they might seem harmless because of their size but when you factor in speed. It changes everything.
The debris is moving at about 10 times the speed of a bullet. So even the tiniest aspects can cause severe damage. when a fragment hit the space shuttle Endeavour in 2007. It left a hole in the radiator that a bullet would have caused if debris were to hit the International Space Station. It could cripple the ISS and harm the crew onboard. This is why the critical parts of the ISS is surrounded by a Whipple shield. Here’s an example of wind, with a piece of insulation covering the aluminium shield. The Shield absorbs the initial impact of the debris clouds so that the full force is diluted, but this is not enough to fully protect the spacecraft, the US military constantly monitors the movement of debris, and if it detects that there’s even a one in 10,000 chance of a potential collision, the space station will manoeuvre to keep the debris out of its path.
On average, this is done about once a year, or related concern is that one collision will set off a chain reaction and lead to another, because each crash generates more debris and makes other crashes more likely, this is known as the Kessler syndrome. So collisions are taken very seriously because they can cause catastrophic damage SpaceX does say it has a plan to prevent crashes, according to the company, the starlink satellites will be able to avoid collisions on their own. By using debris tracking technology from the US Department of Defence, but the European Space Agency points out one of its satellites had to move out of the way of a starlink one in 2019, this potential collision was rare because usually it’s the case of a satellite colliding with a dead one on recommends from another crash, not an active one like starlink, the agency makes it clear it does not blame SpaceX but that the incident highlighted a need for a better system to prevent crashes, unlike on Earth where there are strict rules of the road to follow, there aren’t as many in space.
There is no single law that aims to reduce the amount of space debris in Earth’s orbit, adding on to the problem, new satellites will constantly be launched to replace the old ones, if the old satellites remain in orbit, they become debris and add to the piles of junk Ilan musk says they do have a plan to remove dead satellites, so that we can deal with the satellites effectively and have a good one reentry and have the debris that SpaceX is looking to intentionally deorbit the satellites by firing its thrusters, so they can be brought down to the Earth’s atmosphere, it appears the company may have tested this out with a starlink satellite that was part of the first batch launched in 2019, you can see a significant drop in its orbital height. So SpaceX has a plan to try to avoid collisions and to remove old satellites, it remains to be seen if things go according to plan, and many other companies are setting their sights in space.
The British startup one web is also working on providing Satellite Internet access it filed for bankruptcy earlier in 2020, before being rescued by the UK government which took a $500 million stake in it, Amazon’s project Cooper also wants to be a high speed internet from beyond Earth. It’s clear that space is getting more crowded and as a result, pollution is becoming a bigger problem, even though these companies are working on activities that have the potential to change people’s lives, whether it’s bringing internet access to remote corners of the world, or allowing people to visit another planet one day, there is a dark and dangerous side. And when you’re dealing with objects that are travelling at speeds that our human minds cannot comprehend. It’s a risk that must be managed.