Quality sleep is the foundation of optimal functioning and achieving top results in any profession, and this rule holds with particular weight for astronauts. In the unique and demanding environment of the International Space Station (ISS), where even the smallest mistake can have serious consequences, the crew's ability to be rested, focused, and ready for action is of crucial importance. Precisely with the aim of deeper understanding and optimizing astronaut rest in orbit, a new technology demonstration has been launched as part of the Axiom Mission 4 (Ax-4) mission. This innovative project will test a wearable device designed to collect key biometric data, such as total sleep time and heart rate variability, providing unprecedented insight into the physiology of sleep in microgravity conditions.

The project, conducted under the auspices of the ISS National Laboratory, represents a fruitful combination of expertise and resources from three leading organizations: the global technology consulting firm Booz Allen, commercial spaceflight pioneer Axiom Space, and the Finnish health technology company Oura. The goal of this collaboration is to leverage the potential of so-called "edge computing" to process and analyze biometric data in near real-time. Such an approach will allow crew members to make informed decisions about their own readiness to perform critical tasks, independent of communication with Earth.

A Revolution in Astronaut Health Monitoring

At the heart of this research is a sophisticated wearable device, the Oura Ring smart ring. While on Earth the data collected by this device is usually sent to the company's corporate cloud for analysis and storage, and then presented to the user via a mobile application, in space a completely different, revolutionary approach will be applied. The collected information will be processed locally, on the space station itself, using a specialized edge computing device. The processed data will be immediately available to the crew member for evaluation. This shift from centralized processing on Earth to local processing in orbit represents a key step towards greater crew autonomy.

Josh Arceneaux, director of human spaceflight at Booz Allen, emphasized the importance of this technological breakthrough. "This technology will provide crew members with detailed insight into the quality of their sleep and overall biometric state. This will help them understand how sleep directly affects their physical readiness and ability to perform their duties the next day at the highest possible level," stated Arceneaux. The success of this demonstration would show the potential to eliminate the need for constant communication with Earth for certain activities, a capability that will become increasingly vital for future long-duration missions.

A Step Towards Autonomy on the Way to Mars

The significance of this project extends far beyond the walls of the International Space Station. The ability to autonomously collect, store, and analyze health data is becoming an absolute imperative for future space exploration, especially for ambitious missions like the journey to Mars. During such long-duration journeys, communication delays with Earth, which can last up to 20 minutes one way, make reliance on ground support impractical and risky. Crews will need to be self-sufficient in monitoring their own health and making decisions. The technology being tested as part of the Ax-4 mission provides the foundation for developing systems that will allow astronauts on Mars to assess for themselves whether they are sufficiently rested for complex tasks such as operating a lander or conducting scientific experiments on the surface of another planet.

"Ultimately, this demonstration will show whether we can collect, store, and analyze this data and empower crew members to make decisions without needing to connect with Earth," Arceneaux added. "This is part of a larger goal of transferring capabilities we are accustomed to on Earth to the spaceflight environment." This project is not an isolated incident, but part of a broader strategy to adapt existing commercial technologies for the unique challenges of the space environment.

The Challenges of Sleeping in Zero Gravity

Sleeping in space is fundamentally different from sleeping on Earth. The absence of gravity causes a series of physiological changes that can significantly disrupt rest. Fluids in the body redistribute, accumulating in the upper body and head, which often leads to a feeling of nasal congestion and headaches. Astronauts do not lie down but float, and they must be secured in sleeping bags to walls or the ceiling so they don't drift uncontrollably and bump into equipment. Although this allows for complete muscle relaxation, as the body does not have to support its own weight, the sensation of floating itself can be disorienting. Furthermore, the circadian rhythm, our internal biological clock, can be disrupted because on the ISS, astronauts experience 16 sunrises and sunsets in a single day. The noise from fans and other life support systems also presents a constant source of distraction. For all these reasons, monitoring sleep quality is not a luxury but a necessity for preserving the health and performance of the crew.

Broader Context and Future of Research

The Ax-4 mission, which was launched from Florida, took off not before June 10, 2025. This project fits perfectly with the mission of the ISS National Laboratory, which acts as a public service enterprise enabling researchers from academia and the private sector to use the unique conditions of microgravity. Research conducted on the station not only advances science and technology for space missions but also often leads to innovations that improve the quality of life on Earth, from the development of new drugs to advanced materials. This technology test with the smart ring is an example of how commercial technology, originally developed for the consumer market, can be adapted to solve specific challenges in extreme environments. Through such projects, the ISS National Lab promotes the development of a sustainable and scalable market in low Earth orbit, laying the foundation for the future commercialization of space.