The Russian cargo spacecraft Progress M-20M, which undocked from the International Space Station on February 3, has ended its free flight and is to be sunk in the unnavigated part of the Pacific Ocean on February 11 around 8 pm MSK.

On board the spacecraft there is about a ton of garbage and decommissioned equipment taken from the ISS. Scientists have not come up with ways of utilizing other types of space debris. However, space debris poses a great threat to satellites and astronauts.

The era of active space exploration began 56 years ago. On October 4, 1957 Soviet scientists launched the first artificial satellite from the Earth. One cannot count how many satellites and piloted missions have been launched since then, each one leaving behind a trace in space - a booster, an apparatus that got out of control or a piece of the spacecraft coating.

Such garbage poses a serious threat, Andrei Ionin, a member of the Russian Tsiolkovsky Academy of Cosmonautics and specialist in space policy, points out.

"One must not be fooled by the fact that the size of most parts of that space debris is not big. Because in space particles move at a great speed and one must take into account relative speeds as well," he says.

There have been several instances when debris approaching the ISS presented a threat to the station. Astronauts then put on their space suits and moved to the Soyuz capsules so that they had an opportunity to start moving towards the Earth if needed. So far the ISS has been lucky.

The coating of the American shuttle spacecraft has been damaged twice. In 2006, a tiny space fragment collided with a satellite in its orbit, as a result of which residents of the Far East were left without a TV signal for a while. Taking into account that the planet's technologies are increasingly linked to space, orbital debris can at any moment interrupt the usual course of life for any of us, Igor Marynyn, editor-in-chief of the News of Cosmonautics magazine, notes.

"Currently neither Russia nor any other country has any reasonable solution as to how to clean the space debris. Some propose to use a net. It is an absolutely unrealistic project. Because all the debris fly in different directions at speed of 10-12 km per second. That is faster that a bullet. It is impossible to catch such debris with a net. Some propose to use a magnet. That is also unrealistic as most metals satellites are made of are not influenced by a magnetic field as they are made of duralumin," Marynyn adds.

There have been fantasy ideas to burn the debris with a laser beam from the Earth or launch a cleaning robot into space. But so far the only effective solution is to clean after yourself. For example, a booster block that launches satellites from a low orbit into a high one as a rule is left drifting in space.

If their design includes more fuel and an opportunity of control, then at a certain moment the booster can be sent back into the atmosphere to be burned down. But that makes the project more expensive, that is why not everyone likes that idea, the expert Igor Marynyn asserts.

"There is a great problem with nano- and micro-satellites, which have grown popular lately. They are inexpensive. With a bunch of such satellites one can perform tasks that otherwise are performed by an expensive large satellite. Of course, that is good. But, as a rule, these satellites have a short lifecycle, break down quickly and have no chance to exit the orbit.

Thus by launching nano- or micro-satellites, we add garbage in space. And it is unrealistic to force various institutes and universities, which work with such small satellites, to make engines that would remain in control after the expiration of their lifecycle and would leave the orbit by command from the Earth. That would make such satellites more expensive thus rendering them unprofitable".

According to various sources, currently there are 300-600,000 objects of various sizes freely drifting in space. Half of them are old satellites and their parts. It has been calculated that most of the debris in space is of Chinese (40%), American (27.5%) and Russian (25.5%) origin.

Source: Voice of Russia