As global space activity increases, more space infrastructure is returning to Earth, creating risks for people, property and the environment.
In response, researchers from the University of Southern Queensland (UniSQ) are leading efforts to improve understanding of how satellites and rocket bodies break apart during atmospheric re-entry.
Supported by funding from the Australia–Germany Joint Research Cooperation Scheme, a new project will bring UniSQ researchers together with counterparts at the University of Stuttgart to advance understanding of satellite and rocket break-up.
The research aims to improve predictive tools used to understand how spacecraft behave as they descend through the atmosphere and how different materials and structures interact during the intense heating and aerodynamic forces of re‑entry.
While space infrastructure underpins modern life, up to 40 per cent of the mass of large objects can survive re-entry, highlighting the importance of improving safety and environmental outcomes.
Current prediction methods often rely on simplified models that carry large uncertainties and may overlook important physical processes.
"One common assumption is that once material melts, it plays no further role," Dr Byrenn Birch said.
"But recovered debris suggests that molten metal from one part of a satellite or rocket can affect other pieces as they break up, altering how the object falls back to Earth.
"This could have significant consequences. Around 98 per cent of rocket bodies weighing more than 500kg fly over Australia during their orbit, which makes it critical to improve predictions of how debris behaves as it falls back to Earth."
Because no single facility in the world can fully replicate the extreme heat and airflow of atmospheric re-entry, the project will rely on specialised experiments in two unique research facilities in Australia and Germany.
At UniSQ, researchers will use the hypersonic wind tunnel facility operated by the HypR group to simulate the aerodynamics experienced by spacecraft as they re-enter Earth's atmosphere, helping them understand how objects behave and interact as they fall back to Earth.
In Germany, the University of Stuttgart's PWK4 plasma wind tunnel, operated by HEFDiG, will be used to reproduce the intense heat of re-entry, revealing how spacecraft materials melt under these conditions.
By combining results from both facilities, the team aims to generate new experimental data to improve simulations of how melting materials interact during break-up and better understand the environmental impacts of re-entry.
"UniSQ has a world-recognised hypersonics research program, including observations of real re-entries, and this project strengthens that capability through international collaboration and new experimental data," Dr Birch said.
The Australia–Germany Joint Research Cooperation Scheme is an initiative of Universities Australia and the German Academic Exchange Service (DAAD), supporting the development of early career researchers through collaboration between partner institutions – an essential step in building Australia's growing space industry.
The UniSQ team includes Dr Byrenn Birch and Professor David Buttsworth, along with two early career researchers.
