Velocity Web Site - Aussies track celestial garbage


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An artist's impression of the amount of space junk currently circling the Earth
Credit: NASA

Bits & pieces

In 1965, Edward White lost a glove during the first American space walk. Travelling at 28 000 kilometres per hour, it became the most dangerous garment in history

The Mir space station released more than 200 objects during its first 10 years of operation

In 1997, the space shuttle Discovery fled to a safer, higher orbit to avoid a piece of space junk the size of a football

Space junk is increasing by about 5 percent per year

NASA data shows a current risk of a 'catastrophic' debris strike to the Space Shuttle of one in 200

Flight controllers had to move the International Space Station out of the way in October 1999 when a spent rocket casing came too close.

Aussies track celestial garbage

Don't look now, but there's about two million kilograms of garbage floating above your head. It's been there for over 30 years and it's got a fancy name - space junk! And an Aussie company has come up with a solution.

Experts believe there are more than 200 000 objects floating around up there forming an orbiting garbage dump around Earth. A hazard to spacecraft, some of those bits and pieces scream along at 28 000 kilometres per hour - that's ten times the speed of a bullet!

Objects from one to 10 centimetres in size cause real worry. These are too small and numerous to be individually tracked but could cripple or kill an astronaut in orbit. As an example of the hazard, in 1983 a tiny speck of paint from a US satellite gouged a pea-sized pit in the window of the space shuttle.

A paint fleck might sound trivial, but as every high school physics student knows, a mere speck carries a lethal punch when it's flying at several kilometres per second.

But, wait a minute, why should I worry, if it's in space it can't fall on me, right? Wrong! It can fall and it has. In fact, pieces of space junk enter the atmosphere almost every week.

Most junk burns up in the atmosphere, but if it's big enough they it can come down with a mighty thud - remember the orbiting U.S. space station Skylab? Launched in 1973, it crashed to Earth six years later with the biggest part of it ending up in Australia. That's space junk.

Private enterprise is adding to the congestion. Believe it or not, you can even be buried in space now in lipstick sized containers.

An American company, Celestis Incorporated, conducted its first 'space funeral flight' in 1997 with the ashes of Star Trek creator Gene Roddenberry and 23 other people from all walks of life. In 2008 another US company, Masten Space Systems are offering to send any of your mementos into orbit in a soft drink sized container for a mere $9.95. More space junk.

Seriously, this is a major problem. Some of the objects, tennis ball-sized and bigger, could threaten the lives of astronauts or the International Space Station, and they need to be tracked. That's where the new technology of an Australian engineering company is showing the world how.

NASA and other space agencies world-wide could soon be using space tracking data from Electro Optic Systems (EOS) in the ACT.

Previously space junk was tracked by radar, but this is limited to objects larger than 10 cm, so 90% of lethal junk cannot be tracked or categorized. Radar is also more expensive, slower and less accurate than the EOS system.

The EOS laser ranging system can keep track of thousands of pieces of space junk. Orbiting targets are usually optically acquired and then accurately laser-ranged. Then there is a window of seconds to accurately lock high powered lasers onto the target to assess its speed and direction.

EOS Space Systems has recently demonstrated its laser-based refuse tracking system to the US military. Chief Executive Officer, Dr Craig Smith, said with a facility already operational in Canberra, it could potentially be up and running as a world-wide network within three years.

EOS started in 1983 and its equipment is now used around the world. With it international focus, EOS may not be well known in Australia, but is an outstanding example of how Australian engineering innovation can lead the world.