What junkyard and how did it get up there?
For over sixty years, humanity has been sending man-made objects up to space. But decades of space activity without much thought for the implications it could cause until recently have left us (yes, I said “us”, not just scientists) with a huge problem.
At any given moment in time, there are over 34,000 pieces of baseball-sized, or larger, space junk floating around in space.
Well, floating probably wouldn’t be the right word to use here because they are all traveling at over twenty times the speed of a bullet.
But only debris with a diameter of over 10 cm are detectable with modern ground technology. The European Space Agency estimates that there are approximately 130 million additional pieces of space debris hurtling through space that are too small for us to track.
With all this garbage orbiting our planet, it poses a serious threat to the safety of astronauts and the safety of our assets in space. Since the kinetic energy of an object is proportional to its velocity squared, even seemingly insignificant remnants of rockets or satellites can cause substantial damage to active spacecraft.
Kinetic Energy = 1/2 * mass * velocity²
For instance, the force of a small screw traveling at 17,000 miles per hour in the vacuum of space is equivalent to that of a Jeep Wrangler traveling at 70 miles per hour. Now it’s easy to see how even the tiniest of objects could destroy a spacecraft of the utmost importance such as the International Space Station putting expensive equipment, onboard research, and human lives in danger.
Since when was this a problem?
In 1978, Donald Kessler, a NASA scientist at the time, published a research paper that outlined what is now known as the “Kessler Syndrome” or “Kessler Effect.” In his paper he states:
“As the number of artificial satellites in earth orbit increases, the probability of collisions between satellites also increases.”
This means that as the space around Earth becomes more crowded, the chance of collisions that would result in more space debris also grows. Thus, the amount of debris in orbit would increase at an exponential rate. If this scenario comes to fruition, Earth will be enveloped by an ever-thickening blanket of debris, trapping us, rendering humanity earthbound for all eternity.
Fortunately, NASA and other space agencies and enterprises around the world have taken measures to prevent this from happening. Satellites are now required to do one of three things after their time of service.
- The first is atmospheric reentry, or deorbiting the satellite, so that it burns up in the Earth’s atmosphere. Most satellites now have some sort of deorbiting system which simply reduces the velocity of the satellite so that Earth’s gravity can pull it into the atmosphere.
2. The second method of prevention is maneuvering the satellite to a “storage orbit”, also called “graveyard orbits.” As the name implies, these designated orbits are filled with used satellites and abandoned rocket stages that have fulfilled their duty.
3. Finally, if none of the two above requirements are made, direct retrieval of the spacecraft is necessary.
Although preventative measures have been put in place to combat this issue, already existing space debris could still be potentially devastating.
Why should I care?
I know what you’re thinking: “Could a loose bolt on a murderous rampage fall out of the sky and hit me?”
The short answer is no. The vast majority of objects falling down to Earth disintegrate upon entering the atmosphere due to the tremendous amount of heat generated by drag.
Your chances of getting hit by debris that isn’t a just couple particles of dust are about one in a trillion. To put that into a bit of perspective, you are 700,000 times more likely to get struck by lightning in your lifetime.
“It’s not my problem if some random government satellite is destroyed 21,000 miles above the surface of the Earth.”
Well, I don’t know about that…
If a stray piece of debris were to collide with an active satellite, you could lose the ability to do day-to-day things such as paying with your credit card, using the GPS, watching TV, or browsing the internet (social media included).
So this issue truly is something that affects each and every one of us on Earth.
So what’s being done right now?
Even if we halted all space activity today, the amount of debris would continue to increase in a cascade effect. The only way to neutralize this threat is to actively remove objects from space. Government agencies and also businesses from the private sector are looking for effective and affordable solutions to reduce the amount of debris around Earth.
In September of 2019, the European Space Agency commissioned the first-ever space debris removal mission. It awarded a service contract to a consortium led by the Swiss startup ClearSpace for what will likely become a series of debris removal missions.
The first mission, ClearSpace-1, is scheduled to launch in 2025 and plans on targeting a discarded upper stage of a former ESA rocket. The ClearSpace-1 ‘chaser’ will aim to rendezvous and capture the 100 kg object with its four robotic arms, then deorbit to burn up both itself and the captured piece of debris upon reentry.
With the continued development of this technology, the team hopes to establish a new market for debris removal. But that takes time and the first launch isn’t happening anytime soon.
It’s time to take out the trash.
What we know for sure right now is that we could be just one incident away from total disaster.
This polluting of the heavens is an issue that can’t be overlooked. The problem has to be fixed one way or another.
We can only hope that a long-term solution is designed and implemented before it’s too late, before the trash bag gets too heavy for us to lift.
