Astronauts aboard the International Space Station have successfully controlled a computer interface using only brain signals during the PhotonGrav experiment, part of Poland’s IGNIS mission. Despite physiological changes caused by microgravity, the system achieved an average control accuracy exceeding 80 percent.
The PhotonGrav experiment was conducted under the IGNIS technological and scientific mission to test whether a brain–computer interface (BCI) can function reliably in orbit. BCIs enable users to communicate with and control software directly through brain activity, bypassing muscular movement.
The research team used a proprietary functional near-infrared spectroscopy (fNIRS) device developed by Cortivision. The technology operates similarly to consumer pulse oximeters but is applied to the skull. It emits near-infrared light through the skull to the cerebral cortex and measures changes in blood oxygenation in specific brain regions.
When a region of the brain becomes more active, for example, during mental arithmetic, its oxygen demand increases. The device detects these changes in oxygenation patterns and translates them into signals that can be interpreted by control algorithms.
Researchers were uncertain how the system would perform in orbit.
“We did not know how the signal from the device would behave in space; firstly, due to interference in the station's modules, and secondly, because blood is a fluid that behaves differently in microgravity than on Earth. However, our analyses showed that the quality of the data collected in space was no different from that on Earth,” Dariusz Zapała of Cortivision told the Polish Press Agency (PAP).
Two astronauts participated in the in-orbit study: Sławosz Uznański-Wiśniewski and another, unnamed crew member of the Ax-4 mission. Each astronaut completed three sessions aboard the ISS, with each session lasting about 30 minutes.
In the first phase of each session, the system’s algorithm learned the astronaut’s individual brain activity patterns. In the second phase, participants were instructed to move a colored bar displayed on a screen using only their mental state — by intentionally entering states of focus or relaxation.
According to the researchers, signals recorded in microgravity were stronger than comparable measurements taken on Earth. In orbit, body fluids shift toward the upper body and head, increasing cranial blood volume and bringing the brain slightly closer to sensors positioned on the scalp.
Zapała said these changes were noticeable during preparation.
“We observed this in the experiment: the team had to provide sensor caps in various sizes because the astronaut's head volume actually increased. Caps perfectly fitted on Earth became too tight in orbit,” he said.
The fluid shift effect was also visible in facial appearance, with astronauts showing subtle changes compared to pre-flight images.
The research team defined operational success as at least 70 percent accuracy in recognizing the astronaut’s intended mental state. Results exceeded that benchmark.
“The accuracy of the predictions in the case of the astronauts was significantly above this threshold, averaging 82%. This means they were able to effectively control the object's movement without using muscles. This was the first time this type of study was been conducted in space,” Zapała said.
The next phase of the project will attempt to reproduce the findings under simulated microgravity conditions on Earth. Participants will use the device while lying down with their legs elevated above the head, a position that shifts body fluids upward and mimics some effects of spaceflight.
Researchers say the technology could support autonomous monitoring of neurological health in extreme environments. If effective without direct medical supervision, fNIRS-based systems could improve safety for individuals working in isolation.
“This technology could save the life of a polar explorer or diver by informing the base if they are overloaded or their health is deteriorating,” Zapała said.
He added that the work also contributes to studying brain function in naturalistic, operational settings rather than strictly controlled laboratory conditions.
“We are currently the only company in the world that can boast such a 'Flight Heritage' (space flight experience) in the field of near-infrared spectroscopy in space. Our support services for experiments on the ISS are already part of Axiom Space's core offerings,” Zapała said.
PAP - Science in Poland, Ludwika Tomala
lt/ zan/
tr. RL
