Silicones in space, an interview with the European Space Agency
Space exploration is one of humanity’s most exciting and ambitious pursuits, constantly pushing the limits of what we know and what we can achieve. Behind every successful mission lies a combination of cutting-edge technology and materials designed to withstand the extreme conditions of space. Behind these, silicones have proven to be indispensable, offering unique properties that make them vital for everything from astronaut safety to spacecraft performance.
We asked Premysl Janik, a chemist and material & process engineer at the European Space Agency (ESA), some questions on how silicones are supporting space exploration and some of its most critical challenges. Here’s what he had to say.
What role do silicones play in life-support technologies in space habitats?
Silicones play a crucial role in life-support technologies within space habitats by providing reliable seals in piping, water filtration systems, and gas lines, ensuring the proper functioning of essential systems like air purification and water circulation. Their low toxicity also makes them suitable for use in medical devices aboard spacecraft.
Which are the properties required for materials used in space exploration, especially during human space flight?
Materials used in spacecraft, probes, and structural elements must meet demanding requirements such as durability, stability, flexibility or stiffness, thermal vacuum compatibility, and radiation resistance. These requirements vary depending on whether the materials are exposed to external conditions, like outer space, or used internally in inhabited areas like the International Space Station (ISS). For internal use, additional considerations include sterility, cleanability, resistance to bioburden, fungi, and residual toxicity.
How indispensable are silicones in aerospace applications, and could the industry function effectively without them?
Silicones are indispensable in aerospace applications with currently no suitable replacements for many of them. The space industry has evolved alongside modern synthetic chemistry, and it can take over a decade to develop, industrialise, and qualify materials like silicone elastomers for use in space. Losing access to silicones would significantly impact the industry’s ability to function effectively.
What role do silicones play in ensuring the safety and comfort of astronauts during missions?
Silicone elastomers are widely used in space hardware, including spacecraft, the ISS, and space suits. In pure form, they are ideal for seals, gloves, and other components requiring flexibility, tear resistance, and thermal stability. They also serve as heat- and cryogenic-resistant paints, adhesive tapes, and other practical tools that enhance astronauts’ daily operations.
Are there any new developments in silicone technology that could enhance future space missions or enable longer-duration human spaceflight?
Yes, advancements in silicone technology, particularly in combining silicone elastomers with fluorine chemistries, offer enhanced durability and flexibility, even in cryogenic conditions. Other synergistic formulations are also being explored to target specific property enhancements. Additionally, robust thermal insulation, critical for the successful re-entry of manned or unmanned capsules, often relies on silicone adhesives specifically designed to withstand high temperatures. These innovations could play a key role in enabling longer-duration human spaceflight and advancing missions.
Has ESA collaborated with material scientists or manufacturers to develop new silicone-based solutions for space exploration?
Yes, these include silicone-based black and white paints with extreme solar absorptance properties, adhesive tapes designed for low temperatures, and specialised resins, adhesives, potting compounds, and conformal coatings. While many developments are driven by national space agencies or broader industrial applications, they are frequently adapted for ESA missions, showcasing the versatility and critical role of low-volatility, space-grade silicones.
What message would you like to share with the public about the importance of human space flight?
Human spaceflight is an inspiring field with immense potential and countless discoveries yet to be. However, it’s important to remember that the space sector offers much more than manned missions. ESA science missions, or strategic initiatives such as Earth observation, navigation, telecommunications, and planetary protection, play equally vital roles. Central to these advancements are materials like silicones, which play a critical role in space innovation. For instance, without silicone elastomers, modern space launch vehicles as we know them today would not be possible.
Shaping the future of space
As we look ahead to more missions, it’s clear that advanced materials like silicones will continue to be key for the future of space exploration. ESA’s insights remind us that materials like silicones are essential to achieving new possibilities in space while also benefiting life on Earth.