Space sustainability

Space sustainability aims to keep the space environment safe and healthy, just like we try to take care of our planet. It focuses especially on areas close to Earth, like Low Earth Orbit, because that's where we launch and use the most satellites and spacecraft.

As more satellites and other objects have been sent into space, they've created a lot of space debris floating around. This junk can damage working satellites and make it harder for us to use space safely. We also have to worry about space weather, which can cause problems for spacecraft.

People and countries around the world are starting to work together to solve these problems. They're creating new rules and plans to help make sure we can keep using space for many years to come, without hurting it for future generations.

Fundamentals

Space sustainability aims to make sure space can be used safely and responsibly by everyone. It is important that all countries and people agree to use space peacefully and protect it from harm. This helps us explore and use space without causing damage, keeping it safe for the future.

Agreeing on these ideas can be hard. When countries talk about keeping space sustainable, they often focus on technical solutions, like ways to clean up space junk, rather than making new laws. Learning about space debris helps us understand its effects and work together to protect space for everyone.

Current state

Space sustainability is important because near-Earth space has lots of old, broken pieces from satellites and spacecraft. These pieces are called orbital debris. They can hit working satellites and create even more pieces. This makes it harder and more dangerous to use space for things like talking to each other and watching the weather.

There are also problems from space weather, like solar storms, which can damage satellites. Having too many satellites in the same spot, called overcrowding, makes collisions more likely. When satellites stop working, they are either moved to a special "graveyard orbit" far from busy space paths or left in low orbits where they will eventually burn up when they fall back to Earth. But these old satellites can stay in space for many years, increasing the risk of more debris and collisions.

Areas

The safety of space is very important for all our space activities. One big problem is orbital debris, which are pieces of old satellites and spacecraft floating around. This debris can damage new satellites and make space more dangerous.

There are some guidelines from the United Nations to help manage this debris, but there are no strong laws to make sure everyone follows them.

It is hard for individuals or groups to help clean up space debris. They need permission from the country that launched the satellite. This process is difficult because cleaning up debris can affect other objects in space. Because of this, many countries believe that cleaning up space needs teamwork from all nations, but it is still hard to agree on the best actions to take.

Regulations

We work to keep space safe with rules made long ago. A big rule book is the Outer Space Treaty of 1963. It was made by the United Nations to help countries use space the right way.

Before this rule book, people were worried that space might get hurt. Groups like the International Astronautical Federation and the United Nations Committee on the Peaceful Uses of Outer Space helped make plans to protect space. They started the Committee on Space Research (COSPAR), which still studies space today.

The Outer Space Treaty has rules to stop space and planets from getting dirty. It says space should be shared fairly and that every country must fix any problems caused by their space tools. Later rules, like the 1972 Liability Convention, helped make these ideas clearer.

Attitudes

Countries and groups are working to create better rules to keep space safe for everyone. In 2016, France, the UK, and other countries signed an agreement called the European Code of Conduct for Space Debris Mitigation to help reduce space junk. Many other countries, like China, Brazil, and Mexico, also have their own plans to support space sustainability. But until all countries agree on what space sustainability means, working together is still hard.

The Committee on the Peaceful Uses of Outer Space encourages countries to include rules for managing space debris in their laws. Some countries, such as Switzerland, the Netherlands, and Spain, have done this. However, others, like Japan and Australia, have not yet added these rules to their laws. Some say this is because managing space debris depends on technology and money, which are always changing.

Scientists believe that the space around Earth should be treated like another important part of our environment, just like the oceans. They say that new policies and rules are needed at both national and international levels to protect space for future generations.

Mitigation

Sustainability efforts in space include designing better spacecraft, creating new rules, and cleaning up old space junk. One way to protect satellites is by adding shielding, like the RADARSAT program. Another idea is to fix old satellites so they can keep working instead of becoming trash in space.

The Space Sustainability Rating (SSR) helps encourage companies to build spacecraft that are better for space. It was created by groups like the European Space Agency, Massachusetts Institute of Technology, and the University of Texas at Austin. The SSR uses ideas from Earth-friendly building standards to make sure space missions think about how they might harm space and other satellites.

Tracking satellites is also important. Tools like the Space Situational Awareness system and the US Space Surveillance Network help watch space to predict where debris might go and avoid crashes. Some missions, like RemoveDEBRIS and ClearSpace-1, are testing ways to clean up old satellites and pieces of trash from space.

Growing urgency

There are no rules about space debris and rocket emissions, and this is hurting Earth's atmosphere. More satellites and space junk in Low Earth Orbit (LEO) could make it hard to use this area in the future, a problem known as the Kessler syndrome.

In 2007, China destroyed an old satellite, creating space debris that is still floating around.

When rockets launch, some of their fuel goes into Earth's atmosphere. This can damage the ozone layer, which protects us from harmful sunlight. New rocket fuels are being tested, but we still need to learn more about how they affect our planet. As more rockets launch, these emissions could become a bigger problem.

Beyond LEO

Space sustainability is important not just near Earth, but also in other places like geostationary orbital space and lunar orbit. Geostationary orbit has limited space, so it's important to manage it well. As we work to keep space safe near Earth, we also need to think about keeping space safe around the Moon.