Saving satellites from space junk

16.Saving satellites from space junk

Trevor Chappell


(Australian Associated Press)

An Australian company is helping make the world safe from dangerous space junk as small as a fleck of paint to as big as a bus.

A collision between space junk and an operating satellite can result in the loss of equipment worth hundreds of millions of dollars and disrupt businesses and services.

But they can be avoided if someone tracks the junk, predict its path, and warns satellite operators to change orbit.

Collision alerts are already available but are often inaccurate and don’t allow enough time for satellite manoeuvres.

This is because most tracking systems focus on national defence, and provision of space data for general use is secondary.

Canberra-based EOS Space Systems, which is a subsidiary of ASX-listed Electro Optic Systems Holdings, is working with US aerospace giant Lockheed Martin to establish a major tracking network providing more timely information on space junk to commercial and government customers.

“Our business model is to have a responsive network where we can track things with higher accuracy, on demand, that’s actually useful to satellite operators so they can decide on whether or not they’re going to move the satellite,” EOS chief executive Professor Craig Smith told AAP.

The tracking system involves a large telescope equipped with a laser range-finder that sends out a pulse to the object in space. The pulse bounces off the object and comes back again.

EOS has a tracking facility at Mt Stromlo near Canberra and is building another at Learmonth in Western Australia that is due to open in November 2016.

EOS anticipates having six to eight tracking facilities around the world, including three each in Australia and the US.

It has committed more than $US65 million ($A88.68 million) to establishing the tracking network and will invest more as global demand grows.

Prof Smith says collecting space junk is feasible but expensive – about $500 million per object.

EOS is instead considering using high-powered lasers from the ground to push space junk away from other objects to avoid collisions.

Prof Smith says space junk comprises bits and pieces of intact or defunct satellites – such as bolts, hatches or insulation – ranging in size from flecks of paint to a bus.

The objects orbit the earth, out of control, at up to 30,000km/hr.

The US Air Force tracks about 20,000 objects down to 10cm in size, with an estimated 500,000 bits of junk even smaller than that.

Prof Smith says the amount of space junk is growing at an alarming rate as junk collides with other junk.

Even a tiny piece of junk travelling at high velocity can punch a hole right through an operating satellite, rendering it inoperable.

Prof Smith says there are about 1,000 active satellites, with lives ranging from two weeks to 20 years.

Space junk and an operating satellite collide about once a year.


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