USQ to Study Space Junk Re-entry

An international team of researchers led by the University of Southern Queensland (USQ) have been awarded a grant worth over half a million dollars by the Australian Research Council (ARC) Discovery Projects scheme to study space junk. ARC Discovery Projects scheme grant recipients are selected based on the scheme’s objectives which include supporting excellent collaborative research within fields prioritised by the Australian government. 

As first investigator on the project, Professor David Buttsworth said the $551,000 grant provided a great research opportunity to make a global difference.

“I was very pleased to learn we were recipients – it was a significant outcome for us,” Professor Buttsworth said.

“And in saying that, we’re really excited to be able to use it to make a genuine contribution to the development of improved safety management for spacecraft.” 

The grant will see the international research team, including USQ researchers Professor Buttsworth and Dr Fabian Zander, explore how space junk breaks up as it re-enters Earth’s atmosphere. 

“Capsules carrying astronauts are obviously not intended to break up on re-entry, but some spacecraft, principally satellites, need to be disposed of when they reach their end of life,” Professor Buttsworth said.

“A few decades ago, people would leave them up there in low Earth orbit and eventually, the satellites will re-enter.

“But given the amount of material that's up there now, and the potential for accidental collisions between spacecraft, there's a growing concern about where these broken pieces are going to end up on the Earth – and that is where we come in.” 

While there have been calls to clean up space junk, a key issue with space debris is that it is hard to track and control. However, this could become easier if the mechanisms of space junk break up are better understood. Using USQ’s hypersonic wind tunnel, researchers will be able to test the effects of hypersonic flow on the separation of objects. 

“How spacecraft break up is not currently well known to us,” he said.

“So for our experiment, we’ll place objects that represent components of spacecraft in the hypersonic wind tunnel and then analyse how these objects separate from one another by simulating re-entry conditions.”

“We are also looking to determine the width of debris fields since the items don’t entirely burn up in the atmosphere as they come back to Earth.”

“Instead of falling in a single line, the debris fields are generally elliptical in shape and it’s important for us to establish models for these dimensions for hazard management purposes.”

The study of the break up of space junk as it re-enters Earth’s atmosphere is important in preventing unpredictable and potentially dangerous scenarios.

“Ideally, there is an area in the South Pacific ocean where these things are disposed of,” Professor Buttsworth said.

“However, if your spacecraft ends up being uncontrolled, or you don’t have the fuel reserves, and there’s a danger of it ending up on land, you need to be able to predict and manage this.”

“Hopefully, our findings will improve our management of these re-entry processes, which in turn will protect people and stop damage being done to the Earth.”