A chain reaction
Space debris
At an altitude of 800 km, the lifetime of an object in orbit is 1 to 2 centuries.
In higher orbits, this increases to thousands or even tens of thousands of years. And in geostationary orbit, where there is no atmosphere, it is limitless on a human timescale.
There is no technical solution at this time capable of removing debris from orbit.
The only way to clean up orbital space is to let natural mechanisms below a certain altitude do the job for us. Residual atmospheric drag—albeit tenuous—causes debris to decay and eventually burn up on re-entry. But this phenomenon only occurs in low-Earth orbit.
Existing debris also tend to spawn new debris.
It has been demonstrated in certain altitude bands between 800 km and 1,500 km that a chain reaction is underway, generating more new debris than natural processes can remove.
Even in the unlikely event of a complete launch shutdown, the amount of debris in some orbital bands would continue to grow.
It has been demonstrated in certain altitude bands between 800 km and 1,500 km that a chain reaction is underway, generating more new debris than natural processes can remove.
Even in the unlikely event of a complete launch shutdown, the amount of debris in some orbital bands would continue to grow.
Large plans of imapcts of space debris. Credits: CNES
This profusion of debris is a real danger, particularly bearing in mind that relative velocities in orbit can attain 15 to 20 km/s. A single particle, even small, packs a big kinetic punch.
Impact recorded at 1,000 000 images/s.
too small to be tracked from the ground to enable evasive manoeuvres, their impact would be greater than anything shielding can withstand.
Space debris are also a potential threat to Earth:
although most burn up on re-entering the atmosphere, some survive and reach the surface intact.
although most burn up on re-entering the atmosphere, some survive and reach the surface intact.
