First quantum computer operated in space, despite a rough ride to orbit

[Cheeky Kernel]

Scientists at the University of Vienna have managed something nobody had done before, running a quantum computer in space. Their small photonic quantum processor went up on a SpaceX Falcon 9 in June 2025 and has now been shown to work in orbit. The results are in a preprint on arXiv, so they have not been peer reviewed yet. Even so, it is a nice milestone for a field that usually lives in carefully controlled labs

The main test was whether photons travelling through the device's circuits stayed indistinguishable from one another, which is a basic quantum property the whole approach relies on. They did, and at 32.5 degrees Celsius, which matched what the team had predicted on the ground. The device uses crystalline photon sources and silicon single photon avalanche diodes, known as SPADs, to detect the light

What I found most interesting is how much went wrong along the way. Only three of the six detectors survived the vibration of the launch. Sunlight created so much background noise that measurements could only be taken during the roughly 30 minute periods when the satellite was in Earth's shadow. Radiation from the Van Allen belts degraded the detectors despite aluminium shielding, and glue breaking down in the vacuum cut the laser output from 20 milliwatts to just 4. That is a lot of problems for one small instrument

Despite all that, the team showed that quantum processors can be shrunk down, launched and still function in orbit. That matters for future ideas like quantum links between satellites and ground stations, and possibly processing quantum data in space. The full analysis of the satellite data is not finished yet, so there may be more to come

It is a proof of concept rather than anything practical right now. But every space technology starts somewhere, and the list of failures is exactly what the next mission needs to learn from. What would you use a quantum computer in orbit for, if the technology matures?

Quantum Boldly Spacephys.org