Journey to the centre of the component

ESA engineers investigate the components to be used within space missions down to the most exacting of scales, as shown by this detailed flythrough a pressure transducer, used in satellite propulsion systems.

This fly-through was made possible by the part being put through a medical-style CT scan – short for ‘computed tomography’ – inside a massive X-ray tomography machine based at ESA’s Materials and Electrical Components Lab at its ESTEC technical centre in the Netherlands. This giant item weighs in at 7.5 tonnes, including its internal lead screens. When it was installed, its sheer weight sunk the floor of the Lab by about 4.5 mm.

The machine reveals the details of the interior of a test item without destroying it in the process. The test part is slowly moved around as a thousand X-ray images are taken. Then specialised software stacks these individual images into a detailed 3D model. Total acquisition time depends on the size of the part – it might be completed in six to seven hours. For a larger part multiple acquisitions might need to be performed across different sections of the part, then merged.

The resulting 3D model has a spatial resolution down to around 0.03 mm, portraying not only its surface but also its interior features, so that the engineers can perform a detailed flythrough around – and deep inside – the test part.