Future spacecraft may be able to detect and repair their own structural damage in orbit, a capability that could make long-duration missions and reusable launch vehicles more resilient.
Self-healing materials for spacecraft have been studied for years as engineers look for ways to detect and repair damage that occurs after launch. Now, new work supported by European Space Agency (ESA) aims to move the concept further by combining damage detection and repair in a single structural system.
“Implementing this technology in our systems could have enormous benefits for space transport,” Bernard Decotignie of ESA said in the statement. “It will help to develop reusable space infrastructure and reduce assignment costs. This really proves what European innovation can do for the space sector.”
The technology, called Project Cassandra (short for “Composite Autonomous Sensing And Repair”), uses a composite material known as HealTech, which contains a special healing agent embedded in the carbon fiber layers.
Carbon fiber composites are widely used in spacecraft because they are light and strong. However, over time they can develop microscopic cracks from launch vibrations, structural stresses or extremes temperature fluctuations. When heated, the HealTech material softens and allows the built-in healing agent to flow into small cracks, bonding damaged areas back together and restoring structural strength, according to the statement.
To detect damage, engineers embedded fiber optic sensors into the composite layers. These sensors continuously monitor the structure and can locate the location of cracks or other defects. Once the damage is detected, a network of small heating elements – arranged in a light weight 3D printed aluminum grilles — heats the affected area to about 212 to 284 degrees Fahrenheit (100 to 140 degrees Celsius), which activates the healing process and allows the material to repair itself.
Scientists have already tested prototype structures ranging from small samples to panels about 40 centimeters wide. Early tests show the system can detect cracks, distribute heat precisely to damaged areas and restore structural strength after repairs. Next, the team plans to test adapting the material to a larger form, such as a complete cryogenic fuel tank.
The development of HealTech is a collaboration between the Swiss companies CompPair and CSEM and the Belgian company Com&Sens, through ESA’s Future Innovation Research in Space Transportation programme.
A potential application is reusable space transport systems, where vehicles must withstand repeated launch and reentry cycles. Self-repairing structures can reduce inspection time and maintenance costs between flights while extending the life of spacecraft components. The technology could also prove useful for parts that are exposed to extreme conditions, such as cryogenic propellant tanks that experience dramatic temperature swings.
“I am delighted that we have demonstrated that HealTech composites with health monitoring and heating systems exhibit autonomous damage detection and healing and high resistance to microcracks,” Cecilia Scazzoli, head of research and development for CompPair, said in the statement.
“This makes them suitable for the demanding requirements of propellant tanks and reusable space structures and paves the way for lighter, more maintainable spacecraft components,” Scazzoli added.
