The surge in activity in Low Earth Orbit is generating legal and governance challenges

By Dr Rebecca Connolly, Adjunct Senior Lecturer, Space and Technology Law, University of Sydney Law School

We are in a new era for activities in Low Earth Orbit (LEO) – the zone between the lowest sustainable Earth orbit and up to approximately 2,000km above sea level. In addition to the international space station being in LEO, we now have a Chinese space station, private space flights, proposals for two space hotels and debris removal ventures. However, the most prominent development in LEO is the rising number of small satellites. This presents both opportunities and challenges for an effective global governance framework.

Rise of Mega Satellite Constellations in LEO

LEO satellites are smaller, lighter and much less expensive to construct and launch than satellites in higher orbits. Given the lower altitude of LEO satellites it takes less time for a signal to travel to and from the satellite, resulting in faster data transmission. However, because they are closer to Earth and in constant motion, each satellite can only cover a small area of Earth at any given moment. Therefore, a large number of satellites need to be working together in a network to deliver comprehensive coverage. These ‘mega satellite constellations’ can deliver high-speed internet service to locations around the world where ground-based internet is unreliable or expensive.

Space X’s Starlink, launched in 2019, was the first LEO mega satellite constellation. There is now a suite of private space companies planning to launch their own LEO satellite constellations. According to data published by the UN Office for Outer Space Affairs (UNOOSA), the number of satellites launched into orbit each year has increased rapidly; from 210 in 2013 to 1,200 in 2020 and to 2,470 in 2022. There are approximately 7,700 active satellites in orbit, with 84 percent of these in LEO; over 3,500 satellites belong to Starlink alone. The International Telecommunication Union has received registrations from States for radio frequencies for more than 1.7 million non-geostationary satellites that may be launched into orbit by the beginning of 2030.

International competition to build, launch, and operate LEO satellites is fierce. According to a report in 2021 by the Boston Consulting Group, the communications satellite market is estimated to grow to $40 billion by 2030, largely driven by LEO-based ventures. Around 60 to 70 percent of funding of commercial ventures in space is now directed at LEO endeavours. Governments are also investing in LEO satellite technology, with China, the European Union and the US each developing LEO satellite constellations. Similarly, Australia’s Defence Space Command has contracted Fleet Space Technologies to re-purpose its nextgeneration of LEO satellites for military communications.

The rise in LEO space assets raises legal and governance challenges relating to space debris, space traffic management, the dual-use of satellite technology for commercial and military purposes and the impacts on our dark and quiet skies.

Space Debris

According to NASA, LEO is an ‘orbital space junk yard’ containing millions of pieces of debris flying at high speeds. This includes pieces of spacecraft, non-functional satellites, abandoned launch vehicle stages and other small debris such as batteries, paint flakes and fuel. Collisions between these objects exacerbate the problem, generating further debris. The risk to future space operations from collision with debris in LEO is a serious concern, particularly for crewed spacecraft.

International law attempts to balance the right to the free use and exploration of outer space with the need to ensure that space activities cause no harm interference, attaching liability for damage to States. The non-binding UN Committee on the Peaceful Uses of Outer Space (COPUOS) Space Mitigation Guidelines 2007 and Guidelines for the Long-term Sustainability of Outer Space Activities provide a framework for exercising due diligence in space operations to minimise the creation of space debris. However, with the growing number of commercial and military assets in LEO, there is a renewed call to strengthen the international regulation of space debris to clarify who is responsible for mitigation and remediation.

Space Traffic Management

The increase in congestion in LEO raises challenges for safely accessing, operating within, and returning from space. The development of technical and regulatory provisions for ‘Space Traffic Management’ (STM) is on the international agenda. There is no centralized system, equivalent to an air-traffic control service, for outer space. STM is instead left to national authorities, with non-binding standards containing different obligations, practices and definitions. The Outer Space Treaty requires States to conduct all their activities in outer space with due regard to the corresponding interests of other States and to avoid harmful interference with the space activities of others. This principle operates as a limitation on the right of free use of outer space in the Outer Space Treaty. However, in practice, there is little guidance on how to balance free use with the avoidance of harmful interference. Nevertheless, the due regard principle in the Outer Space Treaty recognises the need to avoid deliberate collisions in space and lays a foundation for international co-ordination.

A range of thorny legal issues for STM are yet to be resolved internationally, including the sharing of space situational data, obligations and specific thresholds for issuing collision warnings, minimum safety standards for spacecraft and any onus to undertake collision avoidance manoeuvres. The need for a global STM framework will become more important as the rising number of space assets in LEO increases the risks of accidents and collisions.

Military and Dual-Use LEO Assets

There is growing recognition that satellites in LEO will be important for national security. Governments depend on space assets for rapidly collecting and disseminating intelligence information, supporting military operations and deploying defence capabilities. The disruption of these space assets would have far-reaching implications. LEO space satellites are at risk from both physical and cyberattacks – as demonstrated by anti-satellite missile testing by both Russia and China, and Russia’s cyber-attack on the Ukraine military communications systems one hour prior to launching its invasion. The recent commitment by some States to not carry out destructive anti-satellite missile testing is a positive step towards developing norms of responsible behaviour. However, the ongoing tension on this issue was highlighted in January, when the United States announced that it would consider military retaliation in response to attacks on satellites. The safety of military space objects brings into question the legal threshold for military interference, intervention, counter-measures and use of force in the space domain.

The importance of LEO satellite broadband on the battlefield has been particularly evident in Ukraine. SpaceX, with funding from private investors and the US government, has provided Ukrainian civilians and their military with access to its Starlink internet service. Ukraine swiftly integrated Starlink into its battlefield communications infrastructure. Ukraine has also used Starlink for strategic offensive military purposes such as to operate unmanned aerial surveillance and aerial combat vehicles. In response, Space X unilaterally restricted the use of the technology by Ukraine for offensive military purposes. This is an example of the complexities involved in the supply of private space technology to Governments in times of military conflict.

The dual-use of LEO satellites for civilian and military purposes raises the question of whether commercial satellites could be considered legitimate military targets, and whether States have a legal onus to safeguard commercial satellites. There is a need for careful consideration of, and clarity on, the international law governing the responsible deployment and use of private space assets in times of conflict.

The Dark and Quiet Skies

The presence of thousands of LEO satellites visible to the naked eye has negative impacts for astronomy. According to the American Astronomical Society (AAA) the trails from LEO satellites will be easily visible in astronomical equipment. Mega satellite constellations also causes concern for indigenous communities that have a unique historical, cultural and religious connection with the night sky. Astronomical observation is important for the continuation of the heritage of first nations people and provides a link between generations.

SpaceX has responded to the concerns regarding the impact of its Starlink satellites on the night sky with initiatives to make the satellites less reflective, but there are doubts about the effectiveness of these measures. In a positive step, the National Science Foundation (NSF) and SpaceX have finalised an agreement to work cooperatively to mitigate the impact of Starlink’s satellites on groundbased astronomical facilities.

There is no international law that prescribes a limit on the brightness of satellites in the LEO. However, Article I of the Outer Space Treaty provides that “[t]here shall be freedom of scientific investigation in outer space” and that “States shall facilitate and encourage international co-operation in such investigation.” The NSF, AAA and the International Astronomical Union continue to work on best practice guidelines and have called for international regulation of the satellite constellation industry with a monitoring, compliance and enforcement mechanism. Discussions are ongoing at UNCOPUOS about possible legal solutions to mitigate the impact of LEO mega satellite constellations on astronomical observations and the protection of our dark skies.

Conclusion

International space law needs to support innovation and space activities in the LEO, while balancing this with the different voices of concern. Space is complex and getting the legal framework right is a challenge. As technology and the use of LEO advances, the legal framework also needs to evolve.