How EcosimPro Simulates Survival in Space
The same software used to design life support for the European Space Agency now powers simulations that keep astronauts alive in the void of space.
Imagine a sealed metal container hurling through the vacuum of space, holding fragile human lives entirely dependent on machinery for every breath of air, every drop of water, and every degree of temperature control. The engineering behind these Environmental Control and Life Support Systems (ECLSS) is arguably one of the most complex challenges of manned spaceflight. For decades, the European space industry has relied on a powerful simulation tool—EcosimPro—to design, test, and perfect the intricate systems that make survival in space possible. This is the story of how virtual modeling breathes life into the void.
Originally developed with European Space Agency (ESA) funding starting in 1989, EcosimPro was designed to tackle the multidisciplinary challenge of simulating environmental control and life support systems for crewed spacecraft like the Hermes shuttle 4 .
These systems are a masterpiece of integration, combining fluid dynamics, thermal control, chemistry, and biology to create a closed-loop habitat. The EcosimPro platform provides a specialized toolkit that allows engineers to model everything from the cabin air itself to the crew inside it 2 .
Air Revitalization
Water Recovery
Thermal Control
Waste Management
The cabin is represented not just as an empty volume, but as a dynamic environment where water condenses and evaporates on walls, and air composition constantly changes. The crew members are modeled with remarkable biological fidelity, accounting for their metabolic activity, breathing rates, evaporative heat loss from skin, and even predictions of their thermal comfort 2 . This holistic approach enables engineers to simulate how a system performs throughout an entire mission, responding to everything from routine operations to potential equipment failures.
While ECLSS systems manage and recycle resources, the ultimate goal for long-duration missions to Mars or beyond is the development of Controlled Ecological Life Support Systems (CELSS). These are ecosystems where biological processes work alongside physical ones to create a more self-sustaining environment.
EcosimPro's role in this cutting-edge research is crucial. Within the framework of ESA's Micro-Ecological Life Support System Alternative (MELiSSA) project, the tool has been used to simulate closed-loop biological systems 2 . The aim is nothing short of understanding how to efficiently recycle waste and regenerate oxygen and food through biological processes, moving us closer to systems that can sustain human life indefinitely in space without constant resupply from Earth.
The Micro-Ecological Life Support System Alternative aims to develop a closed ecosystem for space missions using interconnected compartments with specific biological functions.
To understand how engineers use EcosimPro, let's examine a typical experiment: simulating an Air Management System (AMS) for a spacecraft 2 .
Engineers construct their model by integrating components into a single system using EcosimPro's intuitive drag-and-drop interface 2 :
The experiment imposes a realistic daily cycle of crew activity, which determines their metabolic rate and thus their production of CO2, heat, and water vapor. A simulation is then run to observe how the entire system responds to maintain a habitable environment 2 .
The simulation produces critical data on the cabin environment over time. The results clearly demonstrate the system's effectiveness. The CO2 partial pressure rises and falls with crew activity but is consistently maintained within safe limits by the removal system. Similarly, cabin temperature and relative humidity remain stable and comfortable despite the cyclical inputs from the crew, proving the robustness of the control systems 2 .
| Time Period | Activity Level |
|---|---|
| 00:00 - 06:00 | Low (Sleeping) |
| 06:00 - 08:00 | Moderate (Morning) |
| 08:00 - 12:00 | High (Work) |
| 12:00 - 13:00 | Moderate (Lunch) |
| 13:00 - 18:00 | High (Work) |
| 18:00 - 24:00 | Moderate (Leisure) |
| Parameter | Range |
|---|---|
| O₂ Partial Pressure | 20.9 - 21.7 kPa |
| CO₂ Partial Pressure | 0.2 - 0.6 kPa |
| Cabin Temperature | 21.8 - 23.2 °C |
| Relative Humidity | 45 - 55% |
| Component | Function |
|---|---|
| CO₂ Removal | Removes carbon dioxide |
| Temperature Control | Regulates cabin climate |
| Air Controller | Manages O₂/N₂ levels |
| Cabin | Habitable volume |
EcosimPro is more than a single tool; it's a comprehensive modeling and simulation environment. Its power lies in several key features :
Allows engineers to create and customize components using a language similar to conventional programming, but designed for physical systems 4 .
Employs robust solvers like DASSL and Newton-Raphson methods to handle complex differential-algebraic equation systems 4 .
Pre-built libraries contain components for various disciplines that can be mixed to create sophisticated models 4 .
Models can be exported using the Functional Mock-up Interface standard, allowing them to be shared across organizations .
Initial development begins with ESA funding for Hermes shuttle program 4 .
Expansion to model complete ECLSS systems with biological components.
Application to MELiSSA project for closed ecological systems 2 .
Adoption of FMI standard for model interoperability .
The journey of EcosimPro from a specialized ESA tool to a broader simulation platform demonstrates how technologies developed for space often find applications on Earth. Its principles are now being applied to model hydrogen fuel cell systems for clean energy and other complex industrial processes 1 3 .
Tools like EcosimPro provide the digital proving ground where new concepts for living in space can be tested, refined, and validated without risk to human life.
As we set our sights on returning to the Moon and journeying to Mars, the role of high-fidelity simulation will only grow. They allow engineers to run thousands of virtual missions, anticipate failures, and design systems that are not just functional, but resilient and trustworthy. In the grand endeavor of expanding humanity's presence in space, EcosimPro provides a critical bridge between the impossible and the achievable.