Especially over the 37 past years, satellites were sent out for commercial, educational, security and environmental purposes. During this time, researchers have characterised that the population of space debris rises with time- in correspondence with the hazardous impacts of these conflicting layers. Space Debris is known in different names: ‘Space Waste’, ‘Space Junk’, ‘Space Garbage’, ‘Space Trash’ and more, all meaning- debris of damaged, worn out and old machinery that no longer serves a useful role or natural pieces of meteoroids, aimlessly floating around the earth’s orbit.
Types of Space Debris
Space Debris is of two main types: Natural Space Debris and Artificial Space Debris. Natural Debris are meteoroids- the pieces of asteroidal and cometary materials- that are floating in space. When they penetrate the earth’s atmosphere, they are called ‘Meteors’. On the other hand, Artificial Space Debris is any piece of human-made object that is usually orbiting around the earth’s atmosphere that does not serve any functional purpose. In terms of size, NASA mentioned that are approximately 23,000 space debris pieces that are larger than a softball, half a million marble-sized pieces (4.0 inches or larger), 100 million pieces of 0.04-inch diameter and more pieces that are smaller than a micrometre (0.000039 of an inch in diameter).
The formation of Artificial Space Debris can be due to many reasons, like:
- Accidental or deliberate cast-aways like human waste or tools
- Dead Satellites (Satellites that have zero functional lifetime)
- Deterioration or degradation particles like peeled paint fragments
- Failed missions to space (dysfunctional or failed spacecraft or satellites)
- Fragments from accidental or deliberate explosions and collisions
- Launch Hardware like shrouds, nose cones, bolts, payload covers etc.
- Rocket stage disposals
- Solid propellant slags and more.
Is Space Debris A Problem?
What Can Be Done to Mitigate The Impacts of Orbital Debris?
- Attaching Tethers that is artificially tailed onto larger debris objects to increase the drag
- Computer Programs like possible impactful collision predictors that indicate safer navigation routes where the spacecraft can flee from harm’s way using thruster rockets.
- Debris Shields that enabled additional protection for the spacecraft against space debris like the Whipple Shield (founded by Astronomer Fred Whipple)
- Ground-based lasers to push little particles of debris to lower orbits
- Space Tugs to catch large objects in the space debris layer
- Sponges are giant sponge-like objects that soak up small debris particles
- Tracking Networks like DoD’s Space Surveillance Network that track debris networks and indicate the locations of impactful debris particles (which are larger than 100 mm), this technology is not 100% reliable yet