Junkyard in space

The world’s space agencies–which between them launch roughly 120 spacecraft a year–need to find ways of clearing up the space debris

Written by Huma Siddiqui | Published: September 2, 2013 8:21:27 pm

Mankind might have made rapid strides in space research,but space debris accumulated over the years,is becoming a growing headache for rocket-launching nations. To say that space debris is a menace for spacecraft and active satellites would be an understatement. It can cause impacts and generate even more debris once active rockets or satellites and their disused predecessors collide —spreading even more space junk through Earth’s orbit. The debris can include decommissioned satellites,broken spacecraft,spent rocket stages and fragments left from previous impacts of machines.

No wonder,as soon as a rocket carrying satellites makes it way into the sky,scientists monitoring its progress from the ground stations keep their fingers crossed,hoping that their years of hard work will not become the casualty of an accidental mishap in space. An example of a collision is that of the 2009 US satellite Iridium-33 explosion upon impact with the abandoned Russian satellite Cosmos-2251.

Just to give you a glimpse of this growing problem,ground-based radar systems have recorded about 21,000 individual scraps of junk over the years,much of it still up there. US-based National Aeronautics and Space Administration’s Orbital Space Observatory keeps a tab on the distribution of space debris. It estimates that more than 18,000 chunks of junk larger than 10 centimetres across are hurtling around the planet at thousands of kilometres an hour. The fragments of failed spacecraft,redundant satellites and spent booster rockets are accompanied by hundreds of thousands of smaller scraps of man-made space shrapnel,some with the potential to penetrate or destroy a functioning vessel.

The moot point is this: Space has become a giant dumping ground for jettisoned components and derelict spacecraft. And,the world’s space agencies—which between them launch roughly 120 spacecraft a year—need to find ways of clearing up the junk otherwise manned missions to the Moon and Mars,and the robotic exploration of outer space,may be at risk of colliding with space junk.

A new study carried out by Inter-Agency Space Debris Coordination Committee says that there are some satellite orbits which will become extremely hazardous over the next 200 years if space debris is not actively tackled. The agency has also warned that catastrophic space debris collisions would likely occur every five to nine years at the altitudes used principally to observe the Earth.

The space agencies of Europe,the US,Italy,the UK,Japan and India all contributed to the latest research,each one using their own experts and methodology to model the future space environment. A Sydney-based space technology company,Saber Astronautics,has created a yo-yo like instrument,which keeps space junk from building up by safely de-orbiting decommissioned satellites. Its tether deployer,or DragEN for short,unrolls 200 metres of special conductive string,which interacts with the magnetic field of the Earth to create a force to gently pull a redundant satellite back to Earth.

Interestingly,the first DragEN was selected as the science payload for a student satellite from Manipal Institute of Technology in India. At the end of its 1-year mission,the yo-yo shaped DragEN will deploy,unrolling 200 meters of a special conductive string which interacts with the Earth’s magnetic field. This gently pulls the spacecraft back to earth,clearing the area for new satellites.

In the 1980s,the US Air Force (USAF) only knew about roughly 5,000 pieces of space debris orbiting our planet. By 2010,that number had tripled to 15,639 objects. However, current space trash tracking system can’t even detect some of the smaller bits zipping around up there. That’s why the USAF is developing a new iteration of the venerable “Space Fence” that’s both more precise and more cost effective than its predecessor.

The space fence,technically known as the Air Force Space Surveillance System,is a multi-station radar system that detects objects in space as they pass over America. Commanded from the US Air Force Material Command’s Electronic Systems Center at Hanscom Air Force Base in Massachusetts,the Space Fence is a component of the US Space Surveillance Network (SSN),which is charged with spotting,tracking,and warning of trash falling out of the sky.

A clean up effort is definitely needed on the Earth’s final frontier.

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