A quantum computer has run in space for the first time. A small processor built by physicists led by Philip Walther at the University of Vienna spent eight months in low Earth orbit. It created pairs of light particles, steered them through a chip and measured the result, running several programmed operations.
Satellites collect more data than they can send down. Raw images and measurements wait for a link to the ground, and bandwidth slows everything. Processing some of that data in orbit, before it is sent, is the problem the team wants this kind of device to help with.
Light instead of electrons
The processor uses photons, single particles of light. Lasers shine through crystals to make photon pairs. The pairs run through a glass chip with six channels, and six sensitive detectors record where the photons come out.
The device launched on a SpaceX Falcon 9 rocket on June 23, 2025. In orbit it showed two-photon interference, a basic quantum effect that the operations depend on, even in the harsh conditions of space.
Wear and tear
Space was hard on the hardware. Half of the six detectors failed after launch, leaving three. The team also reports that slow wear of the parts lowered how often it caught matching photon pairs over time.
The next step, the authors write, is to feed real Earth-observation data into the chip. The results are in a preprint that has not yet been peer reviewed.
So far, the chip has proved it can survive and compute in orbit.
