A critical challenge for future space missions

Before any extravehicular activity (EVA), astronauts must eliminate dissolved nitrogen from their bodies in order to prevent the risk of decompression sickness. This denitrogenation phase currently relies on long and demanding protocols, requiring several hours of uninterrupted breathing of pure oxygen.

While these procedures have proven effective aboard the International Space Station, they reveal their limitations in the context of future Lunar and Martian exploration missions, where EVAs will be more frequent and available resources more constrained. NASA is therefore working on the development of new denitrogenation protocols, notably based on reduced-pressure, high-oxygen atmospheres, with the aim of improving both the safety and efficiency of extravehicular activities.

Why NASA selected COMEX

To validate these new protocols, NASA conducted a benchmark of European test centers capable of carrying out complex hypobaric experiments involving multiple subjects simultaneously. COMEX stood out as the only laboratory combining all of the following capabilities:

• ✓a large-volume hypobaric chamber capable of accommodating up to five people,
• ✓highly qualified teams specializing in hyperbaric and aerospace medicine,
• ✓regulatory approval from health authorities to conduct human subject testing.

These unique capabilities led NASA to select COMEX to replicate and complement the tests conducted at the Johnson Space Center in the United States.

Hypobaric testing closely replicating real xEVA conditions

The tests conducted at COMEX consist of a six-hour denitrogenation phase during which participants breathe 100% oxygen, followed by physical exercise sessions performed in a hypobaric chamber simulating an altitude of 9,200 meters (approximately 30,200 feet), still under pure oxygen, corresponding to the operating pressure typically used in the Extravehicular Mobility Unit (EVA) suit, approximately 4.3 psi (0.3 atm).

Volunteers perform a range of effort scenarios representative of extravehicular activity constraints, including stair climbing at varying paces, arm ergometer exercises, object handling, and fine motor skills tasks. An ultrasound station is also used to detect in real time the possible formation of nitrogen bubbles within the body.

Numerous parameters are continuously monitored, including pressure (altitude), breathing gas composition and concentration levels, phase durations, temperature, and humidity, in order to collect essential biomedical data for protocol validation.

Close collaboration with NASA teams

The collaboration between COMEX and NASA was built on a foundation of transparency and scientific rigor. NASA teams visited the COMEX site on multiple occasions to prepare the test campaigns and ensure that the protocols applied were strictly identical to those used at the Johnson Space Center.

In parallel, COMEX teams were trained on-site at the Johnson Space Center in Houston in both equipment operations and test protocol implementation.

Data are shared with NASA in real time and subsequently analyzed jointly. At the end of each test campaign, a detailed report is delivered within short timeframes, contributing to the rapid advancement of ongoing research efforts.

International recognition and strategic perspectives

This first series of tests enabled NASA to officially validate COMEX as a test laboratory for xEVA simulation. COMEX is also the first of the selected centers to have successfully completed this campaign in its entirety, demonstrating its ability to meet the requirements of such a prestigious and demanding client.

Building on these results, NASA has already scheduled a second large-scale test campaign, with several dozen tests planned for 2026, aimed at identifying the most suitable denitrogenation protocol for astronauts involved in future exploration missions.

Profiles selection that meets spatial requirements

The conduct of these hypobaric trials relies on the participation of volunteers whose physiological characteristics are comparable to those of astronauts involved in NASA’s human spaceflight programs. The medical criteria applied are particularly stringent and include, in particular, excellent cardiovascular fitness, high aerobic capacity, the absence of cardiac or respiratory contraindications, and proven tolerance to confined environments.

These scientific requirements, which are essential to ensuring both the safety of the trials and the validity of the data collected, naturally limit the number of suitable profiles and represent one of the major challenges of this type of research involving human subjects. The trials are carried out within a rigorous ethical and regulatory framework, with continuous medical monitoring and real-time measurement of key physiological parameters such as pressure and respiratory gases.

COMEX continues its research activities in this field and remains available to respond to any institutional or scientific requests for information.

An exceptional scientific and human adventure

Beyond its scientific outcomes, this project is a great source of pride for COMEX teams. The mobilization of physicians, engineers, technicians, and project managers with a shared passion for space exploration made it possible to meet a complex challenge within tight timelines, in service of human space exploration.

Through this strategic partnership, COMEX once again confirms its ability to leverage its longstanding expertise in extreme environments to address the most ambitious challenges of international research.

Hypoxia Risk Prevention: Training now available to all aeronautical professionals and high-altitude specialists.

Hypoxia remains one of the most underestimated risks in altitude environments, whether in civil aviation, flight testing, or high-mountain activities. Insidious, progressive, and sometimes difficult to detect, it rapidly impairs cognitive and decision-making abilities, to the point of jeopardizing operational safety

Drawing on its expertise in extreme environments, COMEX is now expanding access to its “Hypoxia Risk Awareness“ training course, initially developed in collaboration with EPNER, the French military test pilot school.
The training is now open to private pilots, airlines, commercial flight crews, instructors, as well as professionals exposed to altitude, particularly in the fields of mountaineering and high-altitude expeditions.

A major issue for aviation safety and high-altitude activities

In both the cockpit and high-altitude environments, the drop in partial oxygen pressure can trigger physiological effects that are often difficult to detect:

• ✓Impaired judgment
• ✓Reduced coordination
• ✓Slower reaction times
• ✓Decreased vision
• ✓A misleading sense of well-being

Each individual reacts differently to hypoxia, making it essential to recognize one’s own early symptoms, a critical factor for aviation safety and risk management.

The training offered by COMEX provides exactly this opportunity, enabling participants to identify their personal warning signs in a controlled and secure environment, supervised by medical specialists.

A realistic training approach combining theory and controlled exposure in a hypobaric chamber

The one-day course follows a comprehensive structure, alternating theoretical instruction with real-world simulations.

The instructional team is composed of COMEX staff for the technical components, and specialists from the Institute of Medicine and Physiology in Maritime and Extreme Environments (Phyrmarex) for the medical aspects.

1. Compréhension du phénomène hypoxique

Participants receive a structured lesson covering:

• ✓The effects of reduced oxygen levels
• ✓Physiological responses,
• ✓LOperational risks in aviation or high-altitude environments
• ✓Prevention procedures and safety guidelines.



2. Practical session in a hypoxic chamber




The practical module is the core of the training. Trainees are exposed to a simulated altitude of 9,300 ft (~2,850 m) with a hypoxic gas mixture containing 12% O₂, in an environment that reproduces in-flight conditions.




Under the supervision of a specialized medical team:



• ✓Physiological parameters are continuously monitored (SpO₂, ECG, heart rate)
• ✓Individual symptoms are observed, identified, and analyzed
• ✓The session can be stopped at any time to ensure safety



This immersive experience enables participants to accurately recognize their own warning signs and develop the correct reflexes for real-life situations.

A training program now accessible to a wide range of professionals

COMEX and PHYMAREX are expanding access to this strategic training program to multiple categories of professionals.

Civil and private aviation

• ✓Private pilots (PPL, CPL, ATPL)
• ✓Airline pilots,
• ✓Instructors and examiners
• ✓Commercial flight crews (cabin crew),
• ✓Technical or maintenance teams required to work at altitude

Airlines and aviation organizations

• ✓Internal awareness training
• ✓Strengthening of aviation safety programs
• ✓Complement to CRM and Human Factors programs

High-altitude activities

• ✓Mountaineers and mountain guides
• ✓Scientific or sporting expeditions
• ✓Professionals exposed to altitude as part of their missions

The objective: to provide each participant with personal mastery of the risk, regardless of their operational context.

Strengthening safety through knowledge

Early recognition of hypoxia is an essential skill, both for aviation safety and for any activity exposed to altitude. Thanks to its expertise, unique facilities, and specialized supervision, COMEX and Phymarex offer immersive training that enables each participant to better protect themselves and act effectively to support collective safety.

To request a quote or schedule a dedicated session for your organization, our training team is at your disposal

Practical Information

• ✓Duration: 1 day (7 hours)
• ✓Location: COMEX Hypobaric Center – Marseille – France
• ✓roup size: up to 8 trainees (10 upon request)
• ✓Prerequisites: medical clearance for hypobaric exposure or a valid pilot/aircrew medical certificate
• ✓Pricing: quotation provided based on company requirements

Training contact:

Ms Anaïs Wackers – contact@comex.fr

A certificate of completion is issued at the end of the session.

COMEX and the Space Sector: A Historic Collaboration for the Future of Life Support in Extreme Environments

For over 60 years, COMEX has been a key player in exploring and mastering extreme environments, thanks to its unique expertise in life support systems under hypo- and hyperbaric conditions. Today, this experience translates into a fruitful collaboration with the space sector. Partnering with agencies such as CNES, ESA, and NASA, COMEX is contributing to the development of life support technologies for habitats designed for upcoming missions, including lunar exploration in the coming years.

Unparalleled Expertise in Pressure Management

Rooted in decades of research and innovation, COMEX’s expertise in pressure management initially emerged in the context of saturation diving, with landmark projects like HYDRA 9 and HYDRA 10. COMEX divers reached record depths of up to 701 meters at the COMEX Hyperbaric Testing Center (CEH), demonstrating the reliability and safety of its confined environments. These technological advancements now form a cornerstone for research into survival systems in extreme environments, including tests on human endurance and simulations of intra- and extravehicular space activities.

Testing Environments for Future Exploration

Today, COMEX’s expertise is embodied in cutting-edge facilities such as the Hyperbaric Testing Center (CEH), a unique European simulator for confined environment testing. The CEH enables the reproduction of hypobaric conditions (a few hundred mBar) similar to those faced by astronauts in space. This capability allows COMEX to collaborate closely with the space sector to develop and validate survival protocols for challenging environments like the Moon and Mars, where life support challenges are significant.

Towards Air and Water Self-Sufficiency: COMEX Purification Projects

To support international space ambitions, COMEX has also developed advanced air and water purification systems. These essential technologies for space missions integrate coupled processes (plasma, photocatalysis, and fine particle filtration) to effectively remove chemical and biological pollutants in confined environments. For instance, the EPURA project focuses on sustainable water recycling, a priority for long-duration missions. Simultaneously, the MINERVE project aims to miniaturize purification equipment for use in space, adapting to specific constraints for intravehicular (IVA) activities.

2025: New Test Campaigns for the Space Sectorl

The collaboration between COMEX and the space sector continues to grow to meet the increasing demands of exploration missions. In 2025, specific test campaigns are planned at the CEH, particularly to validate oxygen pre-breathing protocols, essential for preventing decompression accidents during extravehicular (EVA) activities. These tests represent a crucial step before operational implementation, reaffirming COMEX’s role as a leading innovator in ensuring crew safety and well-being in space.

A Vision for Future Space Collaboration

With its historical experience and advanced technical capabilities, COMEX is ready to tackle the challenges of the future. The company continues to position itself as a strategic partner for space agencies by developing life support solutions tailored to the extreme conditions of space. COMEX’s vision for the future is clear: leveraging its expertise in pressure management and purification systems, the company is helping push the boundaries of human exploration beyond our planet.

Development of the V-Care system for autonomous astronaut training.

The MEDES-COMEX consortium has developed on behalf of ESA a new tracking system for the crew’s physical exercises: Visual Controlled Bodytracking for Advanced Resistive Exercise (V-CARE).

Optimizing real-time body movement tracking

Context :

The International Space Station (ISS) plays a crucial role in facilitating in-depth research into the consequences of prolonged exposure to weightlessness on human health. These studies have identified significant issues such as bone deterioration, muscle atrophy, and the decline of cardiovascular function, among other detrimental effects. The need for resistive exercise as a countermeasure to these impacts of microgravity is now well established, thanks to decades of human experience in space. Indeed, scientific publications, such as those in the Journal of Bone and Mineral Research, have demonstrated the benefits of resistive exercise on bone health.

Therefore, performing physical exercises is essential to maintain optimal physical condition and limit these deconditioning effects. However, when carrying out these exercises, especially when they involve high loads, the risk of injuries, such as muscle pains, cannot be overlooked. A key study published in the Spine Journal in August 2017 notably highlighted the modifications of the spine and muscle atrophy suffered by astronauts, underscoring the importance of a preventative and adaptive approach in the development of physical training programs in space.

Necessity of Innovation in the Space Context:

Currently, once or twice for a 6-month mission (often in the middle of the mission), a real-time teleconference (audio and video) is organized between the astronaut exercising on the ARED (Advanced Resistive Exercise Device) and the team of physical trainers located at a flight control center. The trainers can react in real time when inappropriate positions are observed. This procedure is not sufficient, and it is also restrictive because it requires a real-time connection and does not support the autonomy of the crew, which is an important element to consider. The implementation of a bodytracking system that displays in real time to astronauts when they are exercising at high intensity on ARED is perfectly justified and necessary from a safety perspective. To address this, the idea was to provide ESA with a markerless video capture system of movements allowing self-monitoring (by real-time video feedback) to the subject himself (the astronaut) during resistive exercise on the ISS’s ARED and also compatible with future exercise devices anticipated for upcoming exploration missions.

Presentation of the V-Care System:

To prevent injuries during countermeasure exercise sessions, the V-Care system, developed by COMEX, represents an advanced solution aimed at perfecting resistive exercises in space, particularly aboard the International Space Station (ISS). Utilizing Microsoft Azure Kinect technology, V-Care ensures 3D tracking of body movements without the need for markers. This feature not only facilitates its implementation and use but also allows real-time guidance of the astronaut through visual feedback during exercises.

Faced with technical challenges, including the impact of the participants’ clothing and environmental interferences on the quality of the capture, solutions have been developed to ensure the reliability of the data. For example, it is recommended that participants wear tight, light-colored clothing to minimize infrared signal disturbances and optimize motion capture. Moreover, the optimal positioning of participants relative to the Azure Kinect camera is crucial to maintaining the accuracy of the measurements. Its innovative architecture ensures seamless integration with equipment like the ARED, providing real-time feedback to astronauts to optimize the safety and efficiency of their training. This system represents a significant advancement in the physical preparation of space crews, offering a crucial tool for managing the risks associated with microgravity exercises, while overcoming technical challenges to maintain high quality of movement tracking.

Evaluation and Results:

The thorough evaluation of V-Care, focused on simulations of resistive exercises on a representation of ARED with 11 participants, employed a specific methodology to test the effectiveness and accuracy of the system under conditions mimicking the space environment. This evaluation phase included setting up several success criteria and performance measures, such as the accuracy of movement capture, the stability of the curves generated by the system, and the system’s ability to provide real-time feedback. Participants were invited to perform resistive exercises while wearing outfits optimized for motion capture, thus highlighting the importance of physical preparation and appropriate equipment. The analysis of the results revealed that 56 out of 66 tests were successful, demonstrating the effectiveness of the graphical user interface (GUI), currently based on oscillations, for precise and real-time tracking, and validating V-Care’s capability to provide accurate feedback for adapting and correcting posture and exercise execution.

Impact on Astronaut Training:

The impact of V-Care on astronaut training marks a significant evolution in physical preparation for space missions. By integrating an advanced real-time bodytracking system, V-Care enables better adaptation of resistive exercises, crucial for countering the adverse effects of microgravity on the human body. This technology not only enhances safety by reducing the risk of injuries through immediate posture corrections but also optimizes the efficiency of each training session, ensuring that astronauts maintain optimal physical condition throughout their mission.

Outlook:

The integration of V-Care into training routines on the ISS represents a significant advance in the physical preparation of space crews, offering a crucial tool for managing risks associated with exercises in microgravity. As part of the project’s continuation, a major update of the graphical user interface (GUI) is planned to include body tracking with a 3D representation of the astronaut, their avatar, currently based on oscillations. This development would allow for greater immersion and interaction, thereby facilitating more accurate and personalized feedback. Moreover, the V-Care system could be used on ESA’s “E4D” device for trials aboard the ISS in 2025, marking a step forward in space training technology.

Looking to the future, V-Care could be adapted for missions to Mars, offering a compact and efficient solution for maintaining the musculoskeletal health of astronauts during extended space missions. Studies on the effectiveness of feedback in physical training support the idea that accurate and real-time feedback can significantly improve the quality of exercises by helping to maintain correct body alignment, prevent injuries, and optimize muscle recovery, which is crucial for long space missions where access to full medical facilities is limited. V-Care’s ability to adapt to various training needs and provide detailed performance analyses could transform the way astronauts train, enhancing their health and overall performance in space.

Partner: MEDES has unique expertise in space medicine and in the evaluation/research involving human subjects as well as in the operational implementation of European life sciences experiments conducted aboard the ISS (MARES & SARCOLAB 1 & 2 experiments).