Original article was published by Will Lockett on Artificial Intelligence on Medium
Will SpaceX’s Trash End The Space Age?
Whilst trying to revolutionise space travel, could SpaceX actually end up trapping us on Earth?
Do you dream of being able to spend a long weekend away on the Moon? What about setting up a family on Mars? Or even a future where humans flourish across the Solar System? If so, then you may get quite excited by all of the recent advances in rocket technology, especially as SpaceX wants to get humans to Mars by 2024.
But, SpaceX and other companies may inadvertently trap us here on Earth by creating an impenetrable barrier to space that will last for centuries. This is Kessler Syndrome, and it comes from the throwaway attitude that humanity has become famous for.
Kessler Syndrome is when there is a runaway debris creation from satellite collisions in Low Earth Orbit (LEO). That can be quite hard to visualise so let me paint you a picture.
Imagine if every time you got into a car, it fell to pieces and only deposited you and the seat at your destination while everything else was strewn across the roads. That is what going to space is like.
Every time a rocket launches, it’s different stages fall off, until only the payload in left. Until recently these stages were left to orbit around the Earth feely (normally in LEO). There have been thousands of rocket launches over the past few decades, so space is getting full of these discarded rocket parts. This totals around 1,900 tonnes of debris in LEO (as of 2002 anyway).
Over the decades these have smashed into each other, causing lots of them to turn into fragments of all different sizes. The UCS estimates there are 29,000 bits of debris larger than 10cm, all orbiting at insane speeds. If a piece was to hit a spaceship or satellite it would be the equivalent of hitting it with heavy artillery.
To make things worse, there are loads of satellites orbiting right where these discarded bits of rocket are. According to UCS, as of 1st April 2020, there is at least 1,918 active satellites in LEO — that’s 773 tonnes of satellites floating in LEO!
If they happen to get hit by one of these 10cm chunks, it would fragment into thousands of pieces. These new pieces can then go on to seed yet more collisions, and herein lies the problem. A runaway cascade of collisions happens until the whole of LEO is full of spacecraft killing debris! 2673 tonnes of debris, in fact, whizzing around the Earth at well over supersonic speeds (to stay in LEO you need to be going at least 17,448 mph). This deadly barrier could potentially stop space travel in its tracks.
Currently, large, high-speed collisions don’t happen often, at least until Kessler Syndrome kicks in. At the moment they happen about once every six years, and when they do, it’s huge! In 2009 two communication satellites collided with a closing speed of 11.7 km/s, that’s 26,172 mph. Not surprisingly it created a lot of debris, roughly 2,000 pieces!
So how does it affect us here on Earth?
Firstly, all the satellites that we use day-to-day tend to live in LEO. This means that if Kessler Syndrome happens, GPS would fail, and weather prediction satellites would be destroyed, so it might become best to always take a brolly and a road map wherever you go.
However, the biggest consequence is likely to be our ambitious dreams of space being ruined. Most space missions involve spending some time in LEO before boosting out into deeper space. Simply because it is easier and cheaper than trying to break out in one go. By launching to LEO first, then boosting out of orbit uses a lot less fuel. This means we can carry more payload to space, use smaller rockets, and do it all on a much smaller budget. So getting into LEO is very important for any space mission, whether it is a satellite, getting to Mars or setting up a Moon base, you need to get into LEO first.
But what if LEO is full of spacecraft killing debris? Well, we need to use less efficient trajectories that take us straight up into higher orbits allowing us to pick a small hole in the debris and fly through it. This means more fuel, larger rockets, smaller payloads and an insanely deep wallet to pay for it all.
So, even with the Kessler Syndrome in place, we could still get into space, but it just makes it hugely impractical and expensive. This would put a halt to the vast majority of space programs.
To make this worse, some calculations say that we have gone past the point of no return. We already have enough space junk orbiting us right now to start this exponential increase in collisions. Satellites are already having to do more and manoeuvre more to avoid debris each year. Our cosmic fate appears to already be sealed.
But, even if we aren’t there just yet, SpaceX could tip us over the edge and cause this exploration ending disaster.
SpaceX is trying to launch a constellation of satellites called Starlink that will beam down high-speed internet across the whole Earth. Sounds like a great idea! But it will take around 12,000 satellites, each weighing 260 kg. That would mean the number of operational satellites in LEO would go up by a factor of at least 6 and it would more than double to mass of satellites in LEO.
This incredible number of satellites will ruin pictures of the night sky as they stream overhead, but it could also make our Kessler Syndrome disaster prediction come true very soon.
You see, these satellites will be operated to minimise collisions. So it is very unlikely they will have any issues with the space debris, but will that much mass in orbit all it takes is one large collision to spark a chain reaction of destruction above our heads.
The defunct satellite Envisat, which is currently the largest inactive satellite, and as such we can’t move it out of the way of any collisions is potentially the bigger threat. If this 8,211 kg satellite was to collide with even a small 10cm piece of debris it could break up into thousands of deadly fragments. If Starlink is in operation when this happens, there may be too much debris to track and avoid as the chain reaction speeds up. If this happens we can wave goodbye to our vision of a future in space.
But don’t despair yet. We do have ways to combat this problem and some of them are pretty cool.
SpaceX’s reuseable rockets mean that far less rocket related junk is deposited around the atmosphere from each launch. This is a massive step forward! SpaceX might have a hand in the cause of the orbital disaster, but they are trying to revolutionise rockets to be sustainable for the future.
This is great, but it doesn’t solve the problem right now, after all, we may already be past the point fo no return! We have a lot of ideas on how to tidy up all this space trash, by far my favourite way is with a giant space laser.
If we can place a suitably powerful laser in orbit, it could blast debris back into the atmosphere where it will fall back to Earth and burn up. This wouldn’t destroy the debris, instead, the laser would heat up one side of the debris, pushing it out of its current projection. As long as this laser could reduce the number of debris pieces more quickly than they are being created, we should be able to stop the flow of deadly space debris. Hoorah!
It does look like we are a few years off creating a laser bearing satellite though, and no country is taking responsibility for cleaning up all this mess. But one thing is for sure, we have ignored it for too long, and if companies like SpaceX want to fill LEO with thousands of satellites costing them billions of dollars then they need to help out. After all, who else would build a giant space laser but the bond villain turned good that is Elon Musk?