According to the latest figures, there are currently around 7,500 tonnes of space debris orbiting the earth.
These are close to 30,000 objects larger than 10 cm, close to 750,000 small objects between 1-10 cm and as many as 166 million smaller grains.
Most of this number comes from old satellites and the remains of rocket stages.
The debris is hurtling through space at a speed of up to 28,000 km, and because of the speed, even small objects can cause great danger.
Satellites need to dodge debris
The European Space Agency ESA, for example, receives on average one warning per week about space debris heading for one of the agency’s low-orbit satellites.
The satellites then have to move away and that costs fuel. The International Space Station ISS also has to step aside in the case of fragments larger than 1 cm in diameter.
The rule that 25 years after retirement, artificial hats should be sent straight into the vaporsphere to burn up, is actually rarely followed.
On the other hand, more and more new satellites are being launched. The company SpaceX alone, for example, plans to launch 12,000 satellites.
Trash creates more trash
The number of debris fragments can become exponential, according to astrophysicist Donald Kessler, who described this problem as early as 1978.
Each collision between two fragments of debris breaks them into many smaller fragments. This further increases the risk of collisions, which increase the number of litter breaks even more, thus having a chain effect.
Scientists are now considering possible solutions. A space fence has been mentioned, a “Space Fence” that should use ground-based radar to find space debris.
And from 2020, a laser cannon has arrived on board the ISS station to destroy debris once and for all.
Laser destroys debris fragments
Binoculars detect fractures
The EUSO telescope, originally developed to detect ultraviolet light from cosmic rays, has a 2.6 meter wide lens that detects light reflected from debris.
Based on the laser gun
From the reflection, the telescope calculates the distance and the direction of the light shows how many degrees the laser gun needs to be turned to hit the target.
Plasma pushes debris toward Earth
The laser projectile heats one side of the debris fragment so much that it dissolves into plasma. The plasma expands and pushes the fragment towards the vaporosphere.
