Scientists speaking at the seventh European Conference on Space, warned the international community on the increasing danger posed to space exploration by space debris from over 60 years of exploration.
According to them there are over 150 million small objects which can destroy or degrade a spacecraft if collided with.
The scientists further pleaded for international effort to tackle the issue.
What are space debris?
Space debris include litter constituting of defunct man made objects in the outer space such as, old satellites, disintegrated fragments of satellites and spent rocket stages. They are classified on the basis of their velocity, size and altitude.
How were the debris created?
Scientists note that space debris have doubled in more than a quarter of a century.
Majority of the debris was created during space race between the US and the Soviet Union in the Cold War era often resulting in several failures.
China's Anti-satellite test in 2007 and the 2009 collision between the Iridium Telecom satellite and Russian military's Kosmos-2251 have further accelerated the problem.
Collision with even the tiniest of debris may destroy a satellite. Collision may have a sandblasting effect particularly on solar panels and optical devices which are not protected by the Whipple shield, designed to protect spacecrafts from collision.
Satellites can avoid collision with early warning by shifting position. However, this costs fuel and reduces the operational life of the satellite.
On the scale of danger
While the European Space Agency receives high risk alerts for at least ten satellites per week, with each resorting to one or two avoidance manoeuvres per year, the International Space Station, on collision alert has so far initiated evacuation procedures four times in its history.
What do the scientists say?
Holder Krag, Director, Space Debris at ESA notes, a monitoring radar in 1993 detected around 8000 man-made objects bigger than 10cm, that could inflict catastrophic damage.
The number of objects bigger than 1m, 10cm, 1cm and 1mm currently stand at 5000, 20,000, 7,50,000 and 150 million respectively.
The increase has been termed alarmingly exponential compared to linear trend in the past.
European space conference: Discussions galore!
The yearly conference is the biggest of its kind dedicated solely to space debris. It is scheduled to go on from 18 to 21st April and would deliberate on subjects including measures to mitigate space litter such as de-orbiting satellites when they stop being viable.
Tackling the issue
As number of satellites and debris continue to increase, probability of collision is likely to increase.
As nations including US, China and Russia continue their quest for space domination through acquisition of destructive capabilities such as ASAT, space debris issue could further aggravate.
International efforts and innovative solutions are pre-requisites to solving the problem.