How can we use outer space more sustainably?

6 May 2021

Image: © Alex Zegrachov/

The long-term sustainability of space is something we need to pay greater attention to, according to the ESA and the UN.

Many of us probably take the vastness of space for granted. But just like our planet, we should be paying close attention to how sustainable it is for future generations.

The European Space Agency (ESA) recently hosted a podcast with the United Nations Office for Outer Space Affairs (UNOOSA) on the topic. During the episode, which you can listen to here, host Rosa Jesse described space debris – one of the biggest threats when it comes to space sustainability – as a concern for all nations.

“Space may seem vast, but orbits around Earth are a limited natural resource,” says the ESA. “Millions of debris fragments now fill these orbits, which threaten any spacecraft that crosses their path.”

UNOOSA’s Tanya Keusen explained during the podcast that orbits are a resource less like sunlight and more like oil or gas. If we exploit them too much, she said, it will render them unusable in future.

According to NASA, space debris is mostly human-generated objects. It includes pieces of spacecrafts and flecks of paint, parts of rockets, satellites that have stopped working and fragments resulting from explosions in orbit.

A rocket recently launched by China, in fact, is currently hurtling back to Earth. The rocket weighs around 22.5 tonnes, which would make it one of the largest pieces of space debris to make an uncontrolled re-entry to Earth.

And paying attention to this space debris is becoming more important, ESA space debris analyst Stijn Lemmens told the podcast, as our reliance on outer space continues to grow with satellites and other technologies.

“It’s very much similar to what is happening on Earth when you’re exploiting a resource which can also be useful,” he said.

The infographic below accompanies the podcast episode. It shares information on the trends that pose challenges to long-term sustainability in outer space, such as increasing space traffic and large constellations, as well as some of the approaches ESA and UNOOSA are taking to deal with them.

Infographic showing how we can ensure the long-term sustainability of space.

Click to enlarge. Infographic: ESA

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Lisa Ardill was careers editor at Silicon Republic until June 2021