A simulated image of space debris and satellites in Earth's space environment. Photo courtesy of Marek Möckel, SERC

Gravity. It’s probably the theory best known to man, thanks to Albert Einstein’s genius a century ago, but can modern-day mathematician Joe O’Leary build on this theory to avert a potential disaster in space?

The UniSA PhD candidate is hoping to do just that to more accurately predict the location of satellites orbiting the Earth.

O’Leary has developed some original, “truly terrifying” sets of equations to give new insights into how satellites move around in space and their precise locations.

Given there are now more than 4000 satellites and 750,000 pieces of sizable space debris orbiting the Earth, the chances of a collision are quite high – and rising every day, he says.

The doctoral researcher, who was a finalist in UniSA’s recent Three Minute Thesis competition, says his gravity equations are providing more accurate information about the energy, mechanics and general shape of satellite orbits.

“Space is becoming so densely populated and it is now more important than ever to know exactly where each satellite is,” he says.

“All of us rely on satellite technology on some scale and the most prevalent system – a global positioning system (GPS) – is now embedded in our lives, whether we want to find our way home, watch a movie on Netflix or track the stock market.

“GPS is also heavily relied upon in the telecommunications, defence, emergency services and agricultural sectors.

“Bearing this in mind, if the GPS is so good at telling us where we are here on Earth, we need to determine where the GPS is in space, hence this research,” O’Leary says.

The repercussions of satellites colliding are huge. According to statistical models published by the European Space Agency, there are 29,000 bits of space debris larger than 10 centimetres in the solar system; 750,000 objects between one and ten centimetres and 166 million objects smaller than one centimetre.

“To put those numbers in perspective, if an object of 10 centimetres or greater collided with a satellite it would completely destroy it and be considered catastrophic,” O’Leary says.

“Collisions with objects around one centimetre or less in size would either disable a satellite or damage some of its subsystems.”

As part of his PhD, O’Leary is partnering with the Space Environment Research Centre in Canberra, focusing on ways that relativity can be incorporated into orbit determination software.

He is due to finish his thesis in July 2019.