Laser impulses may help destroy hazardous space debris

Laser impulses may be used to destroy the hazardous debris orbiting in space which poses a serious and ongoing threat to active communication and navigation satellites used by billions of people on Earth, scientists say.
In a new approach, space debris from completed missions - inactive satellites, lens covers, fragments from spaceship disengagements - could be pushed into Earth's atmosphere by laser impulses, causing it to burn up, researchers said.
Pieces even smaller than a smartphone represent danger to our ability to share information and find our way.
While the locations of major space debris are known, fragments smaller than 10 centimetres are difficult to catalogue, and there are 10 times more small pieces than large ones, researchers said.

Due to their remarkably high speeds - up to 15 kilometres per second - small pieces of debris pose a serious threat for space flight and the operation of satellites such as those involved in communications and navigation.
According to Stefan Scharring, Jascha Wilken and Hans-Albert Eckel of the German Aerospace Centre, applying laser-induced damage principles using high-energy laser pulses modify the orbit of debris and push it into the atmosphere, causing it to burn up.

In the weightlessness of space, the researchers said, "a secondary effect of laser-induced damage, which is not immediately apparent in experiments on Earth," when part of an object is ablated, or removed, using a laser beam, the recoil transfers momentum to the object.

They simulated powerful laser oscillations to hazardous materials with the goal of modifying the debris' orbit so that it re-enters and is destroyed by the atmosphere.
Similar laser-based concepts to remove space debris have been proposed in the past. However, the other studies have targeted simple geometric shapes such as plates, cubes, spheres and cylinders that are optimally oriented to the laser source.
The researchers point out that the drawback of such studies is that they fail to address geometrically complex or irregularly shaped objects - characteristic of most space debris - and do not account for the random orientation of those objects in space.

"Our work constitutes the transition from laboratory experiments with idealised flat targets and optimum laser alignment towards simulations of the real world scenario with arbitrarily shaped debris and limited laser pointing accuracy," researchers said.
The research was published in the journal Optical Engineering.