The Space Junk Problem
Space exploration is one of the most thrilling challenges humanity has ever embarked on. However, we may be stopping ourselves from leaving Earth the more we do it… 🤯
Defining the Problem
Humans have been launching things into orbit and space, since the 1950s.
Fun Fact: The world’s first satellite, Sputnik 1, was launched by the Soviet Union in 1957.
Since then, Low Earth Orbit (an orbit at an altitude of 160–1000km above the Earth’s surface) has become a junkyard of rocket parts, broken and functional satellites, missiles, and an additional 100+ million objects that can not be identified or tracked due to their small size. (only debris with a diameter of about 10cm can be detected using our technology)
Our ineptitude or ignorance has gone so far, that we have even left trash (intentionally or not) on the Moon! (read more)
All of this debris moves at speeds 30 000 km/h, that’s 7 times the speed of a bullet, circling Earth several times a day. In case of impact, even the tiniest objects could destroy solid metal.
According to the kinetic energy equation given below,
Kinetic Energy = 1/2 * mass * velocity²
even bodies with a small mass, like remnants of rockets or satellites, can cause extreme damage to really expensive infrastructure like the International Space Station, threatening human lives, equipment, and research.
Let’s Talk Numbers
Currently, there are:
- 2,000 active satellites
- 3,000 dead satellites
- 30,000 pieces of debris larger than 10cm
- 120+ million pieces of space debris larger than 1mm
Read more here!
What does this mean? (Kessler Syndrome)
While the number of things we launch into space increases, so does the possibility of a collision happening in orbit, with catastrophic consequences for all of us.
This was described by NASA scientist Donald Kessler in 1978, stating that if the amount of space debris surpasses a certain threshold, a chain reaction could occur, until Earth’s orbit is unusable. That is because during a collision the debris doesn’t fall from the sky but spray multiple solid pieces creating clouds of debris that could eventually destroy all of our infrastructures along with all our hopes of space travel for centuries. The worst-case scenario: a deadly barrier, too risky to cross, such that all moon and mars colonization plans are terminated. 😱
Possible Consequences & Risks
So, essentially we have created a mess of things in space (pun intended), just like we have here on Earth. The only difference is that the magnitude of the difficulty level and risks in space is way bigger.
Fortunately for us, space debris doesn’t pose a huge risk as of right now to space exploration. The chances that one of us gets hit by a random rocket piece falling from the sky is near zero, because most objects falling towards Earth from space, get disintegrate when entering the atmosphere due to heat caused by drag.
However, we should not pass up this problem just because we can’t seem to recognize what the immediate effects are.
This problem poses a great threat to the lives of astronauts and our assets in space such as the ISS.
Fun Fact: This idea was also popularized in the movie Gravity (definitely recommend it 😄)
As mentioned above, the majority of humanity’s infrastructure is located in Low Earth Orbit. This includes satellite networks, communication, GPS, navigation, weather data, and objects that look out for asteroids. This is a huge threat to the trillion-dollar infrastructure which is located in that region. This problem could cause problems in our day-to-day operations such as using the GPS, watching TV, or surfing the internet. The bottom line is that this problem really affects all of us and we need to find a resolution as well as implement preventative measures.
What are we doing right now?
As space technology develops and reusable rockets are utilized, the amount of junk that we place in space is decreasing. Moreover, when we realize through the trajectories of the debris that we track, that a collision may occur, collision avoidance maneuvers are performed by the satellites and even the entire ISS. In addition, there are ideas being discussed on how we could clean up at least some of the junk out there; some suggestions being lasers, electromagnets, nets, and grappling hooks that would all try and save space travel.
In 2025 ESA will launch ClearSpace-1, which will use robotic arms with the aim of capturing a leftover part of a previous mission.
If this operation succeeds, it will be proven that debris removal in orbit is feasible and hopefully the first of many steps towards cleaning up space!
