Space Sustainability and the Proliferation of Space Debris
Written by Rohit BC
Space: the final frontier. A dream. An opportunity. Humanity has stared at the skies for millennia, fascinated by what lies on the other side. This fascination, combined with innovative methods in science and engineering has ensured that this dream is now a reality. Space probes such as Voyager, Cassini, Parker, and Juno have helped us to understand alien worlds with a degree of closeness that was previously unknown. Rovers such as Spirit, Sojourner, Curiosity, Pathfinder, Discovery, and Perseverance have shown how we can push the boundaries of science. But this push for science and technology has come at a grave cost; through depleting natural resources on Earth and polluting space with a multitude of satellite to understand weather patterns, achieve a deeply connected world, and learn the effects of our abuse on the planet, humanity has turned a blind eye to the ill effects of aiming upwards and onwards.
Space debris consists of anything artificial that can no longer serve us but is still in circulation around Earth. These can be mission-related artefacts, defunct spacecrafts, and other materials discarded in space caught in orbit around the Earth. These materials in orbit revolve at high speeds, potentially posing a risk to other functional spacecrafts in orbit. This risk was seldom unaccounted for, but with more understanding of the risks that they pose the space industry is now coming together to find a solution to this challenge. These pieces of debris are forcing us to consider sustainable practices so that we can continue to use space and reap its benefits by prioritising long-term gains over short-term successes. But this cannot be achieved by just one country and must be an international effort to ensure collective growth. One estimate puts the number of individual satellites in space to upwards of 2,000 as of today. These satellites are never stationary because in order to escape gravity, an orbital speed of over 10,000kmph is required. Even a tiny piece of debris can affect a functional satellite upon impact, thus compounding the existing problem of space debris.
For every application imaginable, the role that satellites play cannot be understated. GPS, weather forecasting, broadcasting, and communications are just a handful of the applications that utilise satellites on a daily basis. These satellites are placed into different orbits, thereby further complicating the issue of space debris at various altitudes. There is approximately 25,000 pieces of space junk over 10cm large littering space, each with disastrous consequences in the event of an impact. The most widely used example of space collision resulting in damage and accumulation of space debris is the 2009 collision between the Iridium 33 satellite and the then defunct Russian military Kosmos-2251 that collided at an altitude of around 800km above the earth at a speed of more than 40,000kmph. Estimates show that the collision created at least 1,000 chunks of visible space debris and an unrecorded number of much smaller debris. Five years after the accident, only 24% of these chunks had decayed, though these statistics can never provide an accurate representation of the damage caused, with the International Space Station (ISS) having had to perform avoidance manoeuvres in order to avoid pieces of space debris.
The higher the altitude of the space junk, the longer the debris can stay in orbit and continue to stay in orbit over an extended period. Geosynchronous orbits are where communications and weather satellites currently orbit the earth, so any untoward incident in this particular orbit would have massive ramifications. Debris within lower orbits stand a better chance of falling towards the planet and often burning up in the Earth’s atmosphere upon re-entry. With our reliance on satellites increasing exponentially, so too is the problem posed by space debris. If not monitored and rectified, it can wreck our existing technology and infrastructure. Many corporate entities and space organisations now seem to be understanding the gravity of this situation and actively pursuing innovative research into clearing space debris. With public awareness on this matter rising, it is just a matter of time before we all pull together to solve this problem, which is now at a real inflexion point. With this idea in mind, the Space Sustainability Rating (SSR) now provides an innovative process to address the challenges in space by encouraging responsible behaviour which can be achieved by increasing an organisation’s debris mitigation strategy and effort, representing the organisation’s commitment to debris mitigation and align with international guidelines.
Organisations are scored based on a range of factors underlying their commitment to adhere to these set guidelines. This concept is currently under development, collaboratively by the ESA and the Space Enabled Research Group at the MIT Media Lab with cooperation from BryceTech, World Economic Forum, and the University of Texas, Austin. Presently, the EPFL Space Center at the Swiss Federal Institute of Technology is selected to operate the SSR, expected to launch in early 2022.
In conclusion, space sustainability is now a critical topic and is something that all businesses and organisations must consider going forward. With our reliance on space systems and satellites expected to rise, it is imperative that we ensure safety in space, not just for other satellites but also astronauts onboard the ISS who are at risk from even the smallest pieces of debris travelling at high speeds. Business and organisations are focused on innovative solutions to ensure space debris does not interfere with existing satellites or affect upcoming missions, thereby ensuring that space remains sustainable and helping us solve some of the most intriguing questions that have us puzzled.