A few weeks ago, Russia shot down one of its old satellites from the 80s. By shot down, I mean just blew it up. The pieces of the satellite, plus pieces of the missile they used to do so, are still whizzing around up there. Astronauts on the ISS had to shelter in escape pods as they made sure that none of the debris from this recent ‘decommissioning’ shot pieces around 17,000 miles per hour. Also, theres thousands of these pieces. For reference, thats roughly the speed a bullet travels, and some of these pieces of space debris are much bigger than a bullet. If those pieces hit another satellite, the same thing could happen, just sans the missile. So more space debris could just mean more exploding satellites and even more debris. This is a good example of some problems we will be facing soon as more and more space debris is shot into, and shot while in, orbit. This problem of cascading effects of space debris is commonly known as Kessler Syndrome.
On NASA’s website, they define Kessler Syndrome as
“Spent rockets, satellites and other space trash have accumulated in orbit increasing the likelihood of collision with other debris. Unfortunately, collisions create more debris creating a runaway chain reaction of collisions and more debris known as the Kessler Syndrome after the man who first proposed the issue, Donald Kessler. It is also known as collisional cascading”
This cascade of space debris could cause many more satellites to be destroyed, and worst case, prohibit us from leaving the planet. Not only would this shut down GPS and Weather Forecasting, but many other services we depend on in our daily lives. So instead of just being dour about the whole problem, why not see whats being done to alleviate the issue, shall we?
A visualization of satellites from the European Space Agency
Some of the current ideas around cleaning space debris include things like crafts with propulsion nets, or robotic arms to catch satellites when they are decommissioned so as to avoid them being hit and thus exploding into more debris. This would allow more effective control to bring them into orbit and have them destroyed properly. The most concerning damage is the seemingly random trajectories of space debris which can affect other equipment in orbit. Controlled crashes are a better way to get rid of space junk and collect it when it is back on Earth. The European Space Agency has some great videos regarding missions planned to retrieve space junk, in as early as five years, as well as how engineers can begin to plan for satellites to be sustainable in space. Sustainability in this context means, how will we get it down when its retired so it wont cause more problems later? You can find the ESA’s posts and videos here.
If you would like to read more about the Russian Satellite news, here is a link to the article Vox did covering the event.