A pair of Sydney PhD students helped sharpen the view of humanity’s most powerful space observatory – without leaving Earth. As an indelible reminder of this thrilling result, Louis Desdoigts, now a postdoctoral researcher at Leiden in the Netherlands, and his colleague Max Charles had tattoos of the instrument their work repaired inked on their arms.
This remarkable technical breakthrough saw University of Sydney researchers develop a software fix that corrected blurring in images made by NASA’s multibillion-dollar James Webb Space Telescope (JWST), restoring crisp performance to one of its vital scientific instruments – all without the need for a space mission or astronaut repair.
The achievement builds on the only piece of Australian-designed hardware on the JWST – the Aperture Masking Interferometer (AMI) – created by Professor Peter Tuthill from the University of Sydney’s School of Physics and the Sydney Institute for Astronomy. The AMI lets astronomers take ultra-high-resolution images of stars and exoplanets by combining light from multiple patches on the telescope’s main mirror, a technique known as interferometry.
However, after JWST began operations, scientists discovered that AMI’s performance was being degraded by subtle electronic distortions in its infrared camera detector. These were injecting fuzziness into recovered images – a problem reminiscent of the predecessor to JWST, the Hubble Space Telescope’s early “blurry vision” after launch, which famously required a space shuttle mission and astronaut spacewalks to correct.
Rather than designing a new lens or mounting such a costly rescue mission, PhD students Louis Desdoigts and Max Charles from Professor Tuthill’s group, also working with Associate Professor Ben Pope (at Macquarie University), created a data-driven, software-only calibration system that fixed the focus from the ground.
Their system, called AMIGO (Aperture Masking Interferometry Generative Observations), uses advanced simulations and neural networks to model how the telescope’s optics and electronics behave in space. By understanding an imperfection in which electrical charge bleeds over into neighbouring pixels, a process known as the brighter-fatter effect, the team developed algorithms that “de-blurred” the images and restored AMI’s full sensitivity.
“Instead of sending astronauts to bolt on new parts, they managed to fix things with code,” Professor Tuthill said. “It’s a brilliant example of how Australian innovation can make a global impact in space science.”
The fix has produced spectacular results. With AMIGO, the James Webb Space Telescope has achieved sharper-than-ever detections of faint celestial objects – including the direct imaging of a dim exoplanet and a red-brown dwarf orbiting the nearby star HD 206893, about 133 light-years from Earth.
A companion study led by Max Charles, a PhD student at Sydney, has demonstrated AMI’s renewed focus by capturing high-resolution images of a black hole jet, the volcanic surface of one of Jupiter’s moons (Io), and the dusty stellar winds of WR 137 – pushing the boundaries of JWST’s capabilities.
“This work brings JWST’s vision into even sharper focus,” Dr Desdoigts said.
“It’s incredibly rewarding to see a software solution extend the telescope’s scientific reach – and to know it was possible without ever leaving the lab.”
Dr Desdoigts has now landed a prestigious postdoctoral research position at Leiden University in the Netherlands. Both studies have been published on the pre-press server arXiv. Dr Desdoigts’ paper has been peer-reviewed and will shortly be published in the Publications of the Astronomical Society of Australia.
Associate Professor Benjamin Pope, who presented these findings at SXSW Sydney in October, said the research team was keen to get the new code into the hands of researchers working on JWST as soon as possible.
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Declaration: The researchers declare no competing interests. Funding was received from the Australian Research Council, Big Questions Institute, Natural Sciences and Engineering Research Council of Canada, National Research Council Canada, National Science Foundation (USA) and NASA.
