Future spacecraft could detect and repair their own structural damage in orbit, a capability that could make long-endurance 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, a new work supported by the European Space Agency (ESA) aims to advance the concept by combining damage detection and repair into a single structural system.
“Implementing this technology in our systems could have enormous benefits for space transportation,” ESA’s Bernard Decotignie said in the statement. “It will help develop reusable space infrastructure and reduce mission costs. This really shows what European innovation can do for the space sector.”
The technology, called Project Cassandra (short for “Composite Autonomous Detection and Repair”), uses a composite material known as HealTech, which contains a special healing agent embedded within layers of carbon fiber.
Carbon fiber composites are widely used in spacecraft because they are lightweight and strong. However, over time they can develop microscopic cracks due to launch vibrations, structural stresses or extreme situations. temperature changes. When heated, the HealTech material softens and allows the embedded healing agent to flow into small cracks, binding damaged areas back together and restoring structural strength, according to the release.
To detect damage, engineers incorporated fiber optic sensors within the composite layers. These sensors continually monitor the structure and can pinpoint the location of cracks or other defects. Once damage is detected, a network of small heating elements, arranged in lightweight materials, is used. 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.
Researchers have already tested prototype structures ranging from small samples to panels about 16 inches (40 centimeters) wide. Early tests show the system can detect cracks, precisely distribute heat 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 firm Com&Sens, through ESA’s Future Innovation Research in Space Transportation program.
One potential application is reusable space transportation systems, in which vehicles must endure repeated launch and reentry cycles. Self-healing structures could reduce inspection time and maintenance costs between flights while extending the life of spacecraft components. The technology may also be useful for parts exposed to extreme conditions, such as cryogenic propellant tanks that experience dramatic temperature changes.
“I am delighted that we have demonstrated that HealTech composites with heating and health monitoring systems show autonomous damage detection and healing and high resistance to microcracks,” Cecilia Scazzoli, head of research and development at CompPair, said in the release.
“This makes them suitable for the demanding requirements of propellant tanks and reusable space structures and paves the way for lighter, easier to maintain spacecraft components,” Scazzoli added.