SpaceX has announced the company's mega-project called Starlink, which will consist of thousands of mass-produced satellites in low Earth orbit (LEO) to provide satellite internet access, is ready for beta testers. 540 Starlink satellites are already in orbit and the company hopes that these satellites will form part of a 12,000 constellation by the year 2027. The project's main aim is to deliver accessible, cheaper, and more reliable high-speed broadband internet all over the world. However, the project confronted with a substantial critique, mainly because of the satellites' potential to clutter the sky and the amount of space debris that they may create over the years. According to the company, Starlink satellites will be meeting or exceeding all regulatory and industry standards to keep space free of debris.

The main reason for space debris to be a growing concern is the risk it poses to satellite-based services, which our modern way of life heavily relies on, such as navigation, communications, weather, and climate monitoring. Millions of pieces of space debris that are flying around at up to 18,000 miles per hour currently in the orbit, nearly seven times faster than a bullet, can damage spacecraft and satellites, and even destroy them. Space debris may also cause spaceflights to be more challenging and expensive and put space exploration at risk in the future. Furthermore, if the space object survives Earth’s atmospheric re-entry, there is also the danger of damage to a property or a person on the Earth's surface.

Space debris consists of pieces of spacecraft, flecks of paint, and non-functioning satellites along with others. Since the first satellite was launched in 1957, more than 9000 satellites were launched to the world's orbit, and only around 2000 of them are still functioning. According to the European Space Agency, current statistical models estimate that there are about 130 million debris objects in space and over 900 000 bits are considered dangerous.

The immediate implementation of appropriate debris mitigation measures is therefore considered an essential step towards protecting the outer space environment. Provisions of the Outer Space Treaty of 1967 which set the basic framework of space law, are too general to deal with the complex and relatively new problems of space debris. Thus, there have been efforts to create a legal framework for debris mitigation, such as the space debris mitigation guidelines of the Inter-Agency Space Debris Coordination Committee (IADC) and the UN Committee on the Peaceful Uses of Outer Space (UNCOPUOS). These voluntary space debris mitigation guidelines increased mutual understanding of acceptable activities in space. Yet, the legal framework consists of non-binding instruments and there is no clear mechanism to force states to take appropriate measures. Nevertheless, some states harmonized their legislation with the guidelines, such as the US, where the debris mitigation standard practices are quite similar to these guidelines. To be able to launch in the U.S, SpaceX needed to get a license from the Federal Communications Commission (FCC), and to get a license, the project should demonstrate compliance with the space debris mitigation.

However, as Stijn Lemmens, Senior Space Debris Mitigation Analyst at the European Space Agency (ESA) put it, it's only after launch that we know how responsible their behavior was. He also adds, ‘’The success rates of compliance with the guidelines is 5% to 15% for satellites -launch vehicle orbital stages do notably better- with success rates of 40-70% in low-Earth orbit-... Operators of any type of large satellite constellation would have to behave far better than most current actors in spaceflight have been doing.’’

Even though only soft law governs the space debris issue, it does not necessarily mean that there are no consequences of polluting the space. According to Article VI of the Outer Space Treaty, states are responsible for their national space activities, whether carried out by government bodies or non-governmental entities. It is important to note that responsibility falls on the state even if it is a non-governmental entity's activity. Thus, states need to authorize and continuously supervise the exercises of their non-governmental entities.

An important aspect of the issue is the damage caused by space debris and the liability for such damages. Article VII of the Outer Space Treaty holds a launching state internationally liable to compensate for damage caused by its space object or component to another state party to the Outer Space Treaty or its natural or juridical persons. The Liability Convention elaborated on these provisions by stating that liability to pay compensation is absolute if the damage is caused on the surface of the Earth or to aircraft in flight. For damage caused “elsewhere than on the surface of the Earth to a space object of another launching State or to persons or property on board such a space object”, liability to pay compensation arises if fault can be attributed to the launching State or of persons for whom it is responsible.

Several issues arise concerning liability. Firstly, it is challenging to identify the debris which caused the damage and trace it back to the launching state of the originally launched object. According to ESA, there are about 22 300 debris objects regularly tracked by Space Surveillance Networks and maintained in their catalog; yet, pieces smaller than 10 cm are usually not tracked or cataloged and cannot be identified. 3Consequently, most of the time it is not possible to determine the launching State.

Secondly, even if the debris can be identified, since only voluntary and non-binding standards and guidelines apply to the operation of space objects and mitigation of debris, there are no mandatory international standards regarding debris mitigation to establish a standard of care to be able to assess the fault.

Another issue derives from the definition of the space debris; it is defined as all man-made objects, including fragments and elements thereof, in Earth orbit or re-entering the atmosphere, that is non-functional in Space Debris Mitigation Guidelines of UNCOPUOS.

However, the Liability Convention regulates the damage caused by ‘’space objects’’ and since there is no certain legal definition of space debris, it is not clear if the term space object also includes space debris. Article I(d) of the Liability Convention and Article I(b) of the Registration Convention states that “The term 'space object' includes components of a space object as well as its launch vehicle and parts thereof.” The description of ‘’space objects’’ does not distinguish between functional objects from non-functional ones, therefore, it may be suggested that “space debris”, whether a non-functional or a functional object, falls within the scope of “space object.”

It must be emphasized that a non-functional piece of Soviet satellite, Cosmos 954, was considered to be a space object when it crashed into Canada and gave rise to the liability of the Soviet Union. Consequently, the Soviet Union paid 3 million CAD to Canada for causing damage to Canadian territory.4 Therefore, the debris should be monitored by the launching state to avoid liability to pay compensation for damage caused by it.

Active Space Debris Removal

A theoretical scenario so-called ''Kessler Syndrome'' suggests that once past a certain critical mass, the total amount of space debris will keep on increasing collisions give rise to more debris and lead to more collisions, in a chain reaction.

According to Luisa Innocenti, who is heading European Space Agency's Clean Space initiative, “Even if all space launches were halted tomorrow, projections show that the overall orbital debris population will continue to grow, as collisions between items generate fresh debris in a cascade effect. We need to develop technologies to avoid creating new debris and removing the debris already up there.'' Thus, active space debris removal is needed along with the compliance with the debris mitigation of newly launched space objects.

Even though some companies are working on technologies to make active space debris removal possible, one of the main issues is a legal one — the permanent ownership of objects launched into outer space. According to Article VIII of the Outer Space Treaty, launching states have jurisdiction and control over their registered objects’ components, irrespective of their size or function. Another State, or the private entity of another State, may not touch, interfere with or remove a space object without the launching State’s consent.

Accordingly, before any debris is removed from orbit, consent from the appropriate country will need to be obtained. 6 Otherwise, since states are internationally liable for damages caused by their space objects, the state which removes the space object would be liable under the Liability Convention. Even when the removal operated by a non-governmental entity, it would not be possible to get around this problem of liability, considering in such cases the launching state of the spacecraft which performs the removal would be liable according to Article VI of the Outer Space Treaty.

ClearSpace-1 which will be operated by a consortium led by Swiss startup ClearSpace will be the first mission to remove a piece of debris from orbit. The ClearSpace-1 mission will target the Vespa (Vega Secondary Payload Adapter) upper stage which left in an about 800 km by 660 km altitude orbit after the second flight of ESA’s Vega launcher in 20137 ESA has already identified active removal as a strategic goal. Because of the growing consensus within the space debris society that active removal will be needed, such debris removal projects are expected to increase in the next several decades. Since it is not practical for every state to remove its space objects from the orbit, it is essential to take necessary steps to regulate such missions under space law.