Imagine a landfill, but in the vast expanse of outer space. Space debris, the remnants of human exploration and exploitation, has transformed the cosmos into the world's largest garbage dump. Let's delve into the gravity of this issue.
Space debris orbiting Earth
Space debris is any human-made object that’s currently orbiting Earth.
- When space debris collides with other space debris, it can create thousands more pieces of junk, a dangerous phenomenon known as the Kessler syndrome.
- Radical solutions are being proposed to fix the problem, some of which just might work.
The ESA-funded ClearSpace-1 mission aims to be the first mission to successfully remove space debris from orbit
The goal is to launch a satellite into orbit and rendezvous with the upper stage of Europe’s Vega launcher, which was left in space after a 2013 flight
- Once the satellite meets up with the debris, it will try to capture the junk with a robotic arm and then perform a controlled atmospheric reentry
Space debris: Trashing a planet
Space debris includes all human-made objects, big and small, that are orbiting Earth but no longer serve a useful function
- Most space junk is floating in low Earth orbit (LEO), the region of space within an altitude of about 100 to 1,200 miles
- If LEO becomes polluted with too much space junk, it could become treacherous for spacecraft, threatening not only our modern technological infrastructure, but also humanity’s ability to venture into space at all
A classic tragedy of the commons
Space debris is everyone’s problem, but no one entity is obligated to solve it
- Left unchecked, the shared resource is vulnerable to depletion or corruption
- There’s no clear answer on how to best incentivize nations to mitigate space debris
- A centralized solution is less costly than a decentralized solution
An Outsized Problem
Space debris of any size poses grave threats to spacecraft.
- Tiny, untrackable micro-debris presents an especially dreadful problem: A paint fragment chipped off a spacecraft might not seem dangerous, but it careens through space at nearly 10 times the speed of a bullet, packing enough energy to puncture an astronaut’s suit, crack a window of the International Space Station, and potentially destroy satellites.
Cleaning up space debris
Most agree on one strategy: get rid of the big stuff first
- Remove debris in low Earth orbit first to prevent cascading collisions
- Electrodynamic tethers
- Ultra-thin nets
- Laser brooms
- Drag sails
The Kessler syndrome
As space becomes increasingly packed with spacecraft and debris, collisions become more likely
- This could trigger a chain reaction of collisions, potentially to the point where near-Earth space becomes a shrapnel field through which safe travel is impossible
- The first known case of a spacecraft being severely damaged by artificial space debris occurred in 1996 when the French spy satellite Cerise was struck by a piece of an old European Ariane rocket
- China conducted an anti-satellite missile test in 2007 that destroyed one of its own weather satellites, triggering international criticism
- In 2009, an unexpected collision between communications satellites produced at least 2,000 large fragments of space debris and as many as 200,000 smaller pieces
- About half of all space debris currently orbiting Earth came from the Iridium-Cosmos collision
The promise and peril of satellite mega-constellations
Space organizations have recently begun launching satellites into low Earth orbit at an unprecedented pace
- The goal is to create satellites that provide high-quality internet access to virtually all parts of the planet
- However, some space experts worry that these satellites could create more space debris
- There are some international efforts to curb space debris risks
- Inter-Agency Space Debris Coordination Committee
- Three broad goals
- Preventing on-orbit break-ups
- Removing spacecraft from densely populated orbit regions when they reach the end of their mission
- Limiting the objects released during normal operations
