Striving towards space sustainability

If space doesn’t remain safe, secure and peaceful, the ability to use it could be denied in the future. Space sustainability involves ensuring that humanity can continue to use outer space for peaceful purposes and socioeconomic benefits now, and in the future.

Space junk

Space junk refers to obsolete satellites, rocket bodies and other fragmented objects in space that no longer serve their intended, useful purpose. There are millions of debris objects in space travelling at high impact speeds.  

To put it into perspective, there are 34,000 objects bigger than 10cm, 900,000 between 1cm and 10cm, and 128 million between 1mm and 1cm.

According to the European Space Agency, the combined mass of debris objects in space is 8,900 metric tons and space junk can travel at up to 29,000km/h. Increasing amounts of space debris therefore threatens active satellites and human spaceflight as orbits become more crowded.

Orbital crowding

The orbits in which satellites travel are a limited natural resource because of the finite amount of space available. The space in Earth’s orbit is therefore limited and is becoming increasingly crowded with satellites and space junk.

Satellite constellations are becoming more common. SpaceX for example has launched 2,335 Starlink satellites, with hope for as many as 42,000 in the future. Starlink provides satellite Internet access coverage to 29 countries on Earth, aiming to extend coverage across the whole globe.

OneWeb’s constellation currently stands at 428 satellites, with plans for a total of 648.

Physical crowding of orbits with satellites and debris can lead to Kessier syndrome, a chain reaction where the density of objects in the Low Earth Orbit is high enough that collisions between objects can create a cascading effect. Here, each collision generates debris that increases the probability of further collisions.

Furthermore, physical congestion and electromagnetic interference from orbital crowding has adverse effects on communication and security in space.

Space security

Militaries use space to support operations with communications, intelligence, navigation and surveillance satellites. These play a vital role in both national and international security.

However, there is an increased risk of satellite interference-based conflict due to more nations integrating space into their security measures. Militaries are therefore developing capabilities to disrupt, degrade or destroy satellites for national security measures.

Solving these issues

These challenges require international cooperation, putting in place policies, practices and technologies designed to ensure that outer space remains safe, secure and peaceful. As global reliance on satellite services and applications increases, so does the importance of such policies as space sustainability is vial for maintaining these benefits for the future.

Technical issues including space debris removal, satellite servicing and traffic management, coupled with policy measures such as space governance, international cooperation, effective regulation and data sharing will ensure space remains safe, secure and peaceful for all.

An initiative is already underway. In 2025 the world’s first debris removal mission is expected to launch. Ensuring space sustainability on a global scale requires policy and technical measures also on a global scale.

It is becoming more important for companies to act and show awareness of space sustainability. SpaceX for example is striving to be the world’s most transparent satellite operator, encouraging others to join it in sharing orbital data and keeping the public and governments updated with detailed information about operations and practices.