A successful deep-space optical communications demonstration on the AAT
Published in the RSAA Lunations
Vol1 Issue63 1–30 June 2025
Secluded in the deepest recesses of AITC2, the laser communication team have been hard at work designing and building systems to squeeze data out of photons from the Moon and beyond. Funded by the Australian Space Agency through the Moon to Mars Mission Demonstrator program RSAA is building capabilities to support space science missions in bringing their data back to Earth. Radio-frequency communications no longer meets the needs of larger and more capable space instrumentation, necessitating the move from radio waves for communication into the near-infrared wavelengths.
A successful demonstration of this deep-space optical communication technology took place on Tuesday 10 June 2025 using the Anglo-Australian Telescope (AAT) at Siding Spring Observatory and the 70 cm Quantum Optical Ground Station at Mt Stromlo. At the time, NASA's Psyche spacecraft was located 1.565 astronomical units away—between Mars and Jupiter—with a one-way light time of 780 seconds. This event marked a significant milestone for the project and constituted a world first.
The team assisted with the instrument change on the AAT, installed their equipment, and aligned it on sky without issue. The AAT staff were extremely supportive, and the team expressed gratitude for their assistance and for the interest and enthusiasm shown for the project. Michelle was a generous and gracious host at the lodge as always, providing a welcoming atmosphere that made the lodge an excellent place to stay.
Despite facing considerable cloud cover during the demonstration, the team successfully observed the laser with the AAT and, with expert support from Jack on telescope operations, moved the laser spot toward the fibre-optic cable. Although clear skies would have made for a perfect demonstration, all program goals were nonetheless achieved. For NASA/JPL, this was particularly significant as it was the first time such a risk had been taken with one of their spacecraft. The success of the demonstration gave NASA/JPL the confidence to consider expanded operating options, including an upcoming demonstration with an ESA telescope in August. The Australian team’s contribution was instrumental in mitigating risk for this future activity.
An additional achievement on the day came from Mt Stromlo, where conditions were perfectly clear. Team members based there operated the Quantum Optical Ground Station to successfully capture and record laser light from the Psyche spacecraft. NASA/JPL were delighted by this result, which will inform further refinements in their operations. Michale, Doris, and Marcus played key roles in operating the telescope and collecting this data, currently being processed by Jamie.
Crucially, the demonstration achieved fibre-optic coupling of starlight onto the highly specialised detector required for such long distance communication—an important result, as a major unknown in deep-space optical communication is the coupling efficiency under atmospheric turbulence. NASA provided models to help predict expected light levels, and the team’s measurements, which showed better-than-expected coupling performance, will feed back into NASA’s link budget calculations for future missions. Tony and Jackie were instrumental in setting up the RINGSS instrument and conducting simultaneous turbulence profile measurements, which will provide essential data to support improved fibre coupling models.
Special thanks to Jamie and Elisa, who organised the AAT time, and managed the packing, transportation, installation, and operation of more than $1 million worth of equipment—more than three cubic metres in volume. The project’s official title, “Australian Deep-Space Optical Ground Station Network,” has now been realised in full. This demonstration is a world first: with NASA/JPL uplinking laser communications from California and the spacecraft downlinking to Australia, it is the first known instance of intercontinental optical communication links involving both uplink and downlink.
It is hoped that this demonstration will support the continued scientific use of the AAT, highlighting not only the technical capabilities of the Australian team and facilities but also providing assurance to future space missions that optical communications is viable even across interplanetary distances.
Mt Stromlo team: Michael Copeland; Doris Grosse; Marcus Birch
SSO team: Francis Bennet; Elisa Jager; Jackie Scholes; Jamie Soon; Tony Travouillon
Francis Bennet
Image: (L-R) Jackie Scholes, Francis Bennet, Elisa Jager and Jamie Soon at the AAT.
