Keeping space clean

Are we any closer to solving the increasing problem of space debris, and has there been significant progress since we last discussed the issue?

The growing risk to satellites

Space debris remains a very real and ever-increasing problem in space.  As at December 2023, the European Space Agency (ESA) recorded that about 16,990 satellites have been placed into Earth orbit since 1957.  11,500 of those are still in space but only 9,000 are still functioning.  Experts predict that more than 20,000 satellites will be launched into space during this decade. 

With these growing numbers comes an increased risk of space debris polluting the Lower Earth Orbit (LEO) and, as a consequence, an increased risk of catastrophic collisions happening with functioning satellites.  The issue of sustainable practices in space is therefore being forced to the top of the space agenda.

Why is sustainability in space important?

The threat to satellites is a problem for humankind because the global economy is now increasingly reliant on space services for everyday activity.  Almost every industry and business worldwide relies on satellites and the infrastructure in Earth's orbit for day-to-day operations, including computing, retail, banking, farming, energy, mass media and communication, defence, construction and travel. 

While the Space Surveillance Network is able to track the larger pieces of space debris, meaning that potential collisions can be flagged and averted, the bigger risk lies in smaller, un-tracked space debris.  Those pieces are unpredictable and travelling at extremely high speeds, meaning they can pose more of a threat than the larger tracked pieces.

Fortunately, for now, collisions are rare.  In 2021, a Chinese satellite was hit by a piece of a Russian rocket that launched several years earlier.  That was the first recorded orbital collision since 2009, when a defunct Russian military spacecraft crashed into an operational communications satellite.  That collision resulted in 1,800 trackable pieces of debris – and no doubt a vast number of smaller, un-trackable objects too. 

Where does space debris come from and how do we get rid of it?

Space debris comes from a variety of sources.  The most obvious is the launching of satellites into LEO.  The process of deploying a spacecraft involves discarding spent rocket bodies, protective shields, covers and other incidental hardware items.  Space debris can also be caused by a satellite not completing its original mission lifetime, for example because it has run out of fuel, or there was another problem on board which means its mission was cut short but the satellite remains in orbit.  A more controversial and (fortunately) less common causes of space debris is anti-satellite testing where a country deliberately destroys one of its own satellites. 

In response to the problem, a number of businesses are working on technologies which aim to create a more sustainable space industry. These are some of the frontrunners:

• Astroscale, headquartered in Japan, has created a magnetic docking system to provide end-of-life services called 'Elsa'. The docking mechanism allows defunct satellites to be captured and removed. The vision is that future satellites will have a magnetic docking plate incorporated into their design when they are built on Earth. Astroscale's spacecraft can then latch on to the satellite when it reaches the end of its life and remove it from orbit before it becomes another piece of space junk. The goal is to start working with commercial satellite operators to prepare for end-of-life services by fitting the magnetic plate.
• ClearSpace UK, a UK-based company, it aims to launch CLEAR (Cleaning of the LEO Environment with Active Removal) a satellite grabbing vehicle within the next two years. The CLEAR mission, funded by the UK Space Agency, aims to envelop two derelict satellites which have been inactive for more than ten years then transport and drop them into decaying orbits.
• Orbit Fab, located in Colorado, US, is developing a satellite re-fuelling service which will be available by 2025. Currently, all satellites must carry all the fuel they will ever use from the moment they launch, which means that once a satellite has burnt through its fuel it becomes space junk. Re-fuelling is therefore an important part of removing and/or re-purposing space debris, giving it a new lease of life. Orbit Fab's vision is for a network of fuel depots parked in orbit and a fleet of fuel shuttles to dock with and refuel client satellites. Orbit Fab has developed a refuelling interface which provides a universal way to refuel satellites on the ground or in orbit. By September 2022, Orbit Fab confirmed that the design had been incorporated into more than 100 commercial satellites.

Incentivising a sustainable space practice

While these advances are encouraging, the problem is that (for the most part) they will only make a significant impact on satellites of the future – provided that manufacturers ensure new satellite designs are compatible with the new technologies.  So what motivation, if any, is there for manufacturers to make sure their designs allow for these new technologies and guarantee more sustainable practices in space?

As we explained in our previous article, guidance on managing space debris has been published by several international organisations.  Broadly, the guidance is aimed at reducing the amount of debris that is created and monitoring debris and communication with other spacecraft operators to help avoid collisions.  However, those guidelines are all voluntary with no agreed enforcement mechanism and they don’t deal with the removal of existing space debris.

That said, there has been some progress over the last two years in attempts to incentivise space operators at national and international levels.  Below are just some examples:

In the UK

• In June 2022, the UK announced it would commence work on a Space Sustainability Standard (SSS).The intended aim of the SSS is to incentivise companies to adopt best practice in space sustainability and officially recognise those who take steps to minimise their footprint on the Earth's orbit. The hope is that the publication of the SSS will make the UK a more attractive place to operate and invest and help unlock sustainable private investment. However, at the time of writing it remains unclear when the standard will be published.
• In March 2024, the UK Space Agency closed a consultation on Orbital Liabilities, Insurance, Charging and Space Sustainability. The consultation set out further detail on government-led initiatives on space sustainability, in particular the proposal for a variable limit of liability for orbital operations, which includes a world-first approach to linking liability limits to sustainable operations. The consultation aims to address industry concerns that the UK approach to insurance for satellite operations is uncompetitive compared to some other nations.

In the EU

• On 13 September 2023, the President of the European Commission proposed an EU space law as a key 2024 initiative. The proposed law (expected to be published shortly at the time of writing) is intended to set out rules on space traffic management and infrastructure safety but is also expected to tackle sustainability issues.

In the US

• In September 2023, the American Federal Aviation Administration (FAA) proposed a rule which it hopes will limit the growth of new orbital debris and reduce the potential for collisions with spacecraft and satellites to promote a sustainable space environment. In summary, the rule would require commercial space operators to choose – as part of licensing requirements – from among five options to dispose of the upper stages of launch vehicles. These include things such as conducting a controlled re-entry, or performing an uncontrolled atmospheric disposal. The proposal was open for comments for 90 days, closing at the end of 2023.The outcome of that proposal is currently unknown.

Global initiatives

• In June 2023, the World Economic Forum (WEF) announced the publication of the Space Industry Debris Mitigation Recommendations. The recommendations advance targets the WEF believes all space actors should collectively adhere to and promote in order to drive productivity in space while maintaining a high standard of sustainability and safety in the entire orbital region.
• The Space Sustainability Rating (SSR) was also launched in June 2023 at the initiative of the WEF. The SSR is a non-profit organisation whose mission is to encourage space actors to design and implement sustainable space missions and operations. The idea is to provide a metric by which space actors' sustainability credentials can be measured by third parties. In turn, that could lead to financial advantages; for example, those with a 'gold standard' would be offered preferential insurance terms.
• In November 2023, the Zero Debris Charter was published. The Charter was facilitated by the European Space Agency and co-developed by 40+ space actors. It is not legally binding but sets out guiding principles in the endeavour towards space safety and sustainability. It also provides targets for 2030 including, for example, the timely clearance of end of mission debris, or keeping the probability of collisions and break-ups to below 1 in 1000/object during the entire orbital lifetime.

These initiatives are clearly a step in the right direction towards sustainable space practice.  However, the problem is that none of them have yet led to a legally enforceable regulatory framework – on either a national or international level – which monitors sustainable practices in space.  Satellite manufacturers are consequently left with little incentive to invest more time and money into building satellites that are compatible with new sustainable technologies.  That is particularly true if their competitors in other jurisdictions aren't currently required to do the same.

A growing problem with growing awareness

While the advancement of sustainable technologies in space is encouraging, the obvious problem remains that the vast majority of satellites already in orbit are not compatible with those emerging technologies.  There is also the issue that there are currently no nationally or globally enforceable regulations around space sustainability, and therefore no obvious incentives for satellite manufacturers to incorporate the sustainable technologies into their new satellite designs.

What is clear, however, is that industry players, national and international organisations have a heightened awareness of the growing problem of space debris and the risks it creates.  Sustainability initiatives on a national and international stage are advancing at a pace, and space actors may not need to wait much longer before sustainable practices in space become a mandatory part of the process.