Space exploration has pushed the boundaries of technology for decades, leading to the creation of innovative materials, manufacturing processes and systems.
Composite materials have been used for space applications dating right back to the United States’ Apollo missions from 1961-1972, where they were used for ablative and other high temperature components.
With advances in composite material technologies, the number of composite material applications for the space sector has expanded, encompassing everything from spaceflight vehicles, satellites, payloads, solar array panels, launch vehicles, and even the rotor blades of NASA's Ingenuity Mars helicopter.
Their low weight, environmental stability and high temperature properties make composites ideal for space applications, including the high modulus carbon fibre reinforced laminates that have become a standard material for many space vehicles. Composite panels are used to support thermal protection systems (TPS) for re-entry, where their low thermal expansion and temperature capabilities mean that less TPS is required, reducing the mass of the vehicle further.
Carbon fibre laminates are also used for satellites and payload support structures and can be found in bus structures, optical benches and RF reflectors. These applications take advantage of the materials’ dimensional stability, low moisture absorption, and ability to withstand both high and low temperatures and the vacuum of space.
With the requirement for larger structures, there have been developments in manufacturing processes such as advances in out-of-autoclave composite fabrication systems. Filament winding is now commonly used to create carbon fibre composite components for the space sector, and high-temperature composites are used for rocket nozzles and re-entry heat shields. These high temperature materials are typically either ablative or ceramic matrix composites.
Fibre-reinforced composites provide low density, high stiffness, strength and toughness, which is making them the next generation of materials for space applications. Because of their light weight, these materials can help reduce the overall mass of a space vehicle or structure, which is vital in an industry where each kilogram added to a launch can cost thousands.
Space Sector Material Requirements
To operate in space, composite materials need to be able to withstand the vacuum environment, radiation and thermal cycling. This means that they need to have a low outgassing rate, be resistant to micro-cracking that can occur as a result of micrometeoroid impact, have good dimensional stability at high and low temperatures, and be able to resist gamma radiation, atomic currents, and UV and Vacuum-UV light. Materials used for space engineering applications should also be able to withstand static and dynamic loads including static acceleration, low frequency dynamic response, high frequency random vibration environment, high frequency acoustic pressure environment, and shock events.
Composite Materials and the Third Space Race
As we enter what some are calling the ‘third space race’, composite materials look set to play an important role. The UK Government sees composite materials as strategically important as innovation drives advancements in a number of industry sectors, including space.
However, to continue this growth, there is a need for cooperation among different organisations to build innovation. As ESA Technology Brokers for the UK, we can help foster an environment that helps companies access the market for composite materials in space, which is expected to reach an estimated £4 billion by 2035.