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 ensure that space can be used safely and responsibly by everyone. It is important that all countries and individuals agree to use space peacefully, protect it from harm, and make the best use of it without causing damage. These ideas help guide how we explore and benefit from space while keeping it safe for the future.

Agreeing on these ideas can be difficult. When countries discuss how to keep space sustainable, they often focus more on technical solutions, like ways to clean up space junk, rather than creating new laws. Learning more 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 is full of old, broken pieces of satellites and spacecraft. These pieces, called orbital debris, can crash into working satellites and cause more pieces to form. This makes it harder and more dangerous to use space for things like communication and weather monitoring.

There are also problems from space weather, like solar storms, which can damage satellites. Too many satellites in the same area, called overcrowding, increases the chance of collisions. Currently, when satellites stop working, they are either moved to a special "graveyard orbit" far from active space paths or left in low orbits where they will eventually burn up when they fall back to Earth. However, these old satellites can stay in space for many years, adding to 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. Although there are some guidelines from the United Nations to help manage this debris, there are still no strong laws to make sure everyone follows them.

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

Regulations

Current efforts to keep space safe rely on rules set in agreements from the 1900s. A key agreement is the Outer Space Treaty of 1963, created by the United Nations to guide how countries use space.

Before this treaty, people worried that exploring space might harm other planets or Earth. Groups like the International Astronautical Federation and the United Nations Committee on the Peaceful Uses of Outer Space worked to study these worries and create plans to protect space. These efforts helped create the Committee on Space Research (COSPAR), which still works on space research today.

The Outer Space Treaty includes rules to prevent harmful contamination of space and planets. It also states that space should be used fairly by all countries and that each country is responsible for any damage caused by its space objects. Later agreements, like the 1972 Liability Convention, helped clarify these rules, making sure countries are responsible for damages from their space objects.

Attitudes

Countries and international groups are working to create better rules for keeping space safe for everyone. For example, 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, efforts to work together are still facing challenges.

The Committee on the Peaceful Uses of Outer Space encourages countries to include guidelines 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 included these rules in their laws. Some say this is because managing space debris depends a lot 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, which added special protection to increase its chances of success. 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

The lack of rules about space debris and rocket emissions is harming Earth's atmosphere and making it riskier for satellites. 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 lots of space debris that is still floating around.

When rockets launch, some of their fuel goes into Earth's atmosphere. This fuel 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 isn't just about the area near Earth called Low Earth Orbit (LEO). Other places, like geostationary orbital space and lunar orbit, also need care. Geostationary orbit has limited space, so managing it properly is important. As we think about space debris in LEO, we also wonder about debris in lunar orbit and discuss ways to keep that space safe too.