· 4 min read
The space and defence sectors are expanding faster than at any point in history. In 2023 alone, more satellites were launched than in the entire first half-century of space exploration. Billions are being invested in AI-powered defence systems, drones, and advanced communications infrastructure. And it's all for a good reason. Space and defence, which depends heavily on satellites and other forms of space-enabled technology, are crucial to growth.
How crucial? Space systems are key to everything from climate monitoring and agriculture to disaster response and global security. Defence spending, too, reflects a new geopolitical reality. With a world less stable than it was ten years ago, and ‘rules-based international order’ on its knees, governments are rightly redirecting funds towards resilience, deterrence, and technological strength.
However, we have to confront a less glamorous reality: the carbon footprint of these activities is substantial. As we continue to pursue growth in space and defense—which we must— then we have to think about how to bring the carbon-intensity down. After all, a worsening climate crisis would only worsen global safety.
The climate crisis is increasing the risk and deadliness of natural disasters; the terrible fires in Los Angeles are still fresh in our memory. It’s also harming supply chains and threatening livelihoods. Soon it will make parts of the world inhabitable, which will drive people to move in mass, thus creating political and social disorder. We are already fighting for resources such as rare-earth minerals and oil; but if we don’t act now, soon we will have to fight for water or clean air.
Every launch into space involves powerful rocket engines that burn through tonnes of fuel and release emissions into the upper layers of the atmosphere. These emissions behave differently from those at sea level. Some trap heat with greater efficiency. Some destroy ozone. All are harder to remove.
At the same time, rising emissions here on Earth are changing the nature of space itself. Greenhouse gases are thinning the upper atmosphere, reducing drag and making it harder for old satellites to deorbit and burn up. More and more hardware is becoming stranded in low Earth orbit. So we’re facing a feedback loop. More launches mean more emissions. More emissions mean worse conditions in orbit. Worse conditions in orbit mean even more complexity, cost and risk. It is a loop we must break.
The bad news is there’s no silver bullet, although materials science can already play a decisive role. Smarter materials, developed using sophisticated techniques that minimise energy use, make satellites lighter, stronger, and more efficient. They reduce the energy required for launch, extend mission lifespans, and enhance thermal performance in extreme conditions. In defence, the same principles apply. Composites and coatings can make drones fly further on less fuel. They can reduce the maintenance burden on high-performance aircraft. They can extend the operational life of missiles and other guided systems. In a sector where every gram and every joule counts, the right material can tip the scales.
These already exist. Next-generation composites combine low weight with extremely high durability and electromagnetic shielding. They’re designed to meet the twin demands of performance and sustainability. And this is not just about cutting emissions. It’s also about reducing cost, waste, and downtime. Long-term, true sustainability demands that we make items more cheaply than by the conventional method to achieve mass adoption. It is also about making the tools of security and progress cleaner, leaner, and longer-lasting. Retrofitting vehicles and perhaps spacecraft – much more sustainable than building new equipment – is also possible. Advanced materials and composites are capable of upgrading what is already out there. And by doing all this, we maintain the viability of space itself. Yes, space is vast, but it’s still a domain we can’t afford to pollute, congest or abandon. We should be thinking about this now; prevention is always better than cure.
The space and defence industries will continue to grow. The world needs them to. But if we’re to scale responsibly, we need to bake sustainability in at every stage, not as a box-ticking exercise – there’s already enough bureaucracy in the space and defence sectors – but as a core engineering principle. In other words, not as an add-on, but as a foundation. Innovation in materials, and the adoption of high-quality lightweight materials, is one of simplest and most friction-free ways of making these critical fields more sustainable.
We should never apologise for building the future, but we should build it well. However the political winds blow, the climate crisis isn’t going away, and it will make itself felt more than it is already. Given this, we should take the long view now and strive to build technology that is sustainable as well as effective. And here’s a bonus: reducing the energy used during the production process makes that technology cheaper, not more costly.
It’s on people like us, working in advanced materials, to make sure that the materials of the future make that future liveable. We need to focus on keeping down costs and increasing scalability – without compromising on quality.
illuminem Voices is a democratic space presenting the thoughts and opinions of leading Sustainability & Energy writers, their opinions do not necessarily represent those of illuminem.
