Highly sophisticated materials and engineering are crucial for the success of missions for space exploration and settlement. Here, Tommaso Ghidini, head of the Structures, Mechanisms and Materials Division of the European Space Agency (ESA) guides readers through the extreme properties that materials used for space missions must possess.
In photos snapped by spacewalkers, space looks like the most tranquil environment imaginable: absolute stillness bathed in even sunlight, receding out to endless, star-dotted blackness. That is an illusion. From Earth orbit to deep space and the planetary surfaces beyond, space missions involve exposure to some of the most demanding and hostile operational environments in which human engineering products are required to function.
The scope of a given mission dictates the particular environmental parameters it will face. A low-orbiting Earth observation mission faces very different constraints from a geostationary telecommunications satellite, or an exploration mission out to deep space - or still more a planetary lander. Specialist engineers work to ensure that the materials, mechanical parts and processes used to manufacture a spacecraft or a rocket satisfy both ground and flight functional requirements and constraints of the mission. Their selection must guarantee high reliability despite the extremely aggressive conditions around them while performing very complex and sophisticated tasks.
Materials and processes are chosen by prioritising those already successfully used for identical or very similar applications in other space missions - in terms of environment constraints and mission lifetime - and those for which satisfactory evaluations are obtained in tests that simulate various aspects of space, as well as those included in approved data sources, including ESA and NASA databases.