France’s space agency CNES is mobilizing its CADMOS center in Toulouse to prepare and operate a new suite of microgravity experiments for ESA astronaut Sophie Adenot’s Epsilon mission to the International Space Station (ISS). The work extends a three-decade track record supporting European human spaceflight, from Mir and the Space Shuttle to long-duration ISS research campaigns. CNES outlined the program and the role CADMOS plays across development and operations in an update published on 6 October 2025.
What CADMOS does
CADMOS, the Center for the Development of Microgravity Applications and Space Operations, was established in 1993 at CNES’s Toulouse Space Centre to structure France’s human spaceflight activities. Uniquely in Europe, it combines end-to-end capabilities: designing and preparing experiments with laboratories and industry, qualifying hardware for flight, and conducting real-time operations with the ISS crew and ground systems. This integrated model spans the full value chain from requirements definition to post-flight data delivery.
How experiments are selected
CNES prioritizes two objectives when selecting ISS investigations:
- Support for the French and European scientific community that requires access to microgravity for advanced research.
- Development of technologies that pave the way for future crewed exploration missions.
Projects may be national or conducted in partnership with other agencies such as ESA or NASA, guided by a CNES roadmap that aligns scientific goals and exploration needs.
Why microgravity matters
Microgravity suppresses the effects of weight, thermal convection, buoyancy, sedimentation and hydrostatic pressure, enabling phenomena to be observed that are masked on Earth. Key research domains include:
- Materials and fluid physics: studies of fluids, plasma, solidification and evaporation.
- Life sciences: plant and animal biology, exobiology and human physiology, including cardiovascular, neuroscience and organoid research. Space medicine leverages accelerated but reversible physiological changes to advance understanding and countermeasures.
- Fundamental physics: niche areas such as cold atoms.
From lab concept to in-orbit results
CADMOS converts scientific requirements into flight-ready experiments and mission procedures, then oversees execution and data return. The typical lifecycle involves:
- Co-design with research teams and manufacturers to define hardware and protocols compatible with ISS constraints.
- Qualification and certification for flight safety and integration.
- Launch and installation via cargo resupply missions.
- Commissioning and operations from the CADMOS control center, with astronauts acting as subjects or operators as needed.
- Ground-controlled investigations when possible, minimizing crew time and maximizing efficiency.
- External payloads mounted outside the station when required, as demonstrated by programs such as ACES and Euro Material Ageing.
- Data distribution to principal investigators for analysis and publication.
Support for the Epsilon mission
While the ISS is an international laboratory where experiments are typically conducted by any trained crew member, CNES assembles a cohesive national contribution when a French ESA astronaut is on board. For Sophie Adenot’s Epsilon mission, CADMOS is preparing a portfolio spanning science, technology and education to advance programmatic objectives and highlight French expertise. Training and operational support are designed to ensure efficient execution on orbit and rapid science return.
European context and continuity
CADMOS is part of a network of European centers that operate on behalf of ESA. Its integrated development-and-operations role supports Europe’s sustained contribution to the ISS program, ensuring continuity in microgravity research whether or not a French astronaut is currently assigned. The approach is intended to benefit the broader community while maturing capabilities relevant to future human exploration.
