Cassandra demonstrator diagram

Diagram showing the design of Cassandra demonstrator, from left, the optical fibres connecting the sensors and right, the heating elements.

Healable spacecraft structures could soon be possible thanks to cutting-edge composite technology. Swiss companies CompPair and CSEM with Belgian company Com&Sens have partnered with the European Space Agency (ESA) to modify their self-healing carbon fibre product for use in space transportation.

Project Cassandra (a loose abbreviation of Composite Autonomous SenSing AnD RepAir) includes sensors and a heating element into a composite carbon-fibre material, allowing spacecraft to autonomously repair initial stages of damage .

Cassandra is part of ESA’s Future Innovation Research in Space Transportation (FIRST!) Initiative which is finding and testing innovative technology that will benefit European space transportation.

A prototype of the composite structure was created by integrating a network of fibre-optic sensors into HealTech’s resin-imbued fibres. The sensors pinpoint any damage to the structure. Once spotted, the material is heated through integrated 3D-printed aluminium grids to 100–140°C.

Various samples of the material ranging from 2x10 cm to 40x40 cm have undergone testing. The tests focused on the efficacy of the material’s damage monitoring, homogenous heating and self-repair abilities. Additionally, thermal shock tests were conducted to monitor the response of the material to the typical conditions of a cryogenic tank.

[Image description: three grey squares with black and red lines on them denoting the optical fibres, metallic heaters and sensors. Scale indicators show the squares are 440 mm wide and the grid lines are spaced between 10 and 20 mm.]