Abstract

Since the launch of Sputnik in 1957, chrome and nickel steel alloys have been widely used for building satellites and launchers for manned and unmanned missions. Their high resistance to extreme temperatures makes them ideal for spacecraft heatshields. The James Webb Space telescope used steel molds to construct its 6.5m primary mirror containing pressed beryllium powder. Steel tubes are also used for building a telescope’s cooling system. Likewise, solar sails use steel booms to ensure proper deployment. Various other sub-systems on board the International Space Station and other spacecraft are made of steel and other high-value materials. These examples give an insight into the application of steel and its unprecedented needs in the booming Space industry.
Although humankind continues to benefit tremendously from advancements in Space Science and Technology, there is a growing concern over space sustainability. Millions of Space debris, large and small, orbiting Earth threaten the space ecosystem. To address this alarming issue, many investors, regulators and insurers have stepped in to support Active Debris Removal missions to clean up Space. However, the current approach is to deorbit space debris, but the remnants returned to Earth are non-biodegradable objects, polluting the oceans and affecting marine lives. Space trash is an immense resource that should be reused for manufacturing newer systems in orbit. The feedstock needed for on-demand manufacturing of new or replacement parts and components can be produced by recycling materials in orbit, including those previously used for packaging or current space debris. This includes the abundance of steel and other metals on the orbiting space debris. However, research on recycling space debris and additive manufacturing in Space is still in its infancy, hindering the goal of achieving an in-space circular economy.
Considering the importance of net-zero manufacturing on the ground and in Space, recycling materials from space debris for on-demand manufacturing in orbit would be environmentally friendly and economically profitable. This paper presents the technological challenges in recovering and reusing steel and other high-value materials floating around the Earth’s orbits. Further, the benefits of in-orbit recycling operations for implementing on-demand design and fabrication services will be introduced. The state-of-the-art additive manufacturing in Space, the technological gaps, and the step towards manufacturing green steel from space debris will be covered. Such capabilities will significantly reduce launch costs and carbon footprint by decreasing the number of launches and the need for ground-based fabrication. The paradigm shift toward in-space manufacturing aligns well with our curiosity to continue to explore the universe and improve lives on Earth whilst achieving a sustainable circular economy on Earth and in Space.