As our lives become more reliant on satellite technology, the more we are likely to be affected by their costly collisions with one of the million pieces of debris littering our space environment.
RMIT researchers are playing their part in helping satellites work out a safe orbit to avoid the collisions that create at least some of the debris.
Professor Kefei Zhang and his team from the SPACE Research Centre have joined with researchers from Electro Optic Systems and Japan’s National Institute of Information and Communications Technology as part of the Australian Government-funded Space Environment Research Centre (SERC).
Other members of SERC, looking at aspects of the problem such as tracking and manoeuvring, are the Australian National University, Optus and Lockheed Martin Australia.
RMIT’s role in the $20 million, five-year project is to develop new tools to improve the accuracy and reliability of predictions about the behaviour of space debris in relation to the orbit of satellites.
This includes a new model for predicting how the debris will be affected by space weather, atmosphere drag and the Earth’s gravitational field.
Zhang, from the School of Mathematical and Geospatial Sciences, said while humans had only been in space for 57 years, before too long our planet would be surrounded by an impenetrable layer of junk and rubbish – and each piece, no matter how small, posed a threat to satellites.
“Each collision results in what is known as Kessler syndrome – where more junk and debris is created and it has a cascading effect,” he said.
“Satellites cost around $AUS700 million each, and we rely on them for everything from the GPS in our cars, to getting cash from an ATM in another part of the world, and from TV to weather prediction.
“But even a 1cm piece of debris can cause major damage and disruption to services.”
Zhang said his group was looking at both laser and optical measurements and getting reliable and accurate information about debris to enable their behaviour and movement to be predicted.
“This is a very big issue. Space is now polluted with more than a million pieces of debris,” he said.
“Billions of dollars have been spent on the International Space Station and in 2012-13 alone there were four emergency evacuations because of unpredicted debris that required the ISS crew to retreat temporarily to their Soyuz spacecraft.
“You can see the dents in the structure that this debris causes.”
A collision between US and Russian satellites in 2009 accelerated the need for solutions to be found to the problem, when it resulted in 3000 new pieces of space debris.
With enough warning, this kind of incident can be avoided – and that is where Zhang and his team come in.
“We need to be able to work out where and when a collision might occur and provide a safe path for the satellite to be moved to so it can avoid it, away from other debris in the area,” he said.
“There are many near misses with man-made things such as defunct and active satellites, rockets, things dropped by astronauts on their space walks and fuel cells.
“It’s a big, expensive and very challenging problem, but it’s great that Australia has taken the lead.”
SERC is providing students with generous postgraduate research top-up scholarships, which give them the chance to spend time in Tokyo and California as a part of their studies.