On June 13, 2021, at the G7 summit in Carbis Bay, Cornwall, delegates from Canada, France, Germany, Italy, Japan, the United States of America, the United Kingdom and the European Union (EU) pledged to combat the increasing amount of space debris crowding Earth’s orbits. This is a powerful political stance, as international attention was given to a phenomenon that is becoming more and more real and could potentially jeopardize current and future space programs.
During the summit, the importance of following international guidelines governing the mitigation of this phenomenon was highlighted. In this sense, depending on the type of orbit, the Inter-Agency Space Debris Coordination Committee (IADC) has indicated different standards to be followed. If the orbital altitude is below two thousand kilometers (LEO), it is recommended that satellites be re-entered to the Earth’s atmosphere within twenty-five years of mission completion. For GEO satellites, after completion of the mission, they should be re-orbed into a graveyard orbit, located about three hundred kilometers above geostationary orbit to prevent any interference with operational satellites.
Finally, satellites located in Lagrangian points are required to clear the area as soon as possible at the end of their mission, so that it can then be used again by new satellites.
There are also some technical measures that, if followed, can limit the damage caused by wreckage and space debris. One of these is passivation, which involves dispersing a satellite’s fuel in order to avoid accidental explosions at the end of the mission.
It should be noted that, although mitigation measures are effective in containing debris growth, some removal systems must be put in place. This is for two reasons: first, the creation of new space debris due to malfunctions or collisions between space objects cannot be entirely avoided. Secondly, one has to deal with the debris that has accumulated over the last sixty years. The American satellite Vanguard I, launched in 1958, is still in orbit. It has been estimated that the population of debris larger than ten centimeters could increase by seventy-five percent in the next two hundred years.
The need to actively counter the build-up of space debris (which was also discussed at the G7) can be met by Active Debris Removal (ADR) measures. Actually, there are actual space missions aimed at dropping space debris into the atmosphere to cause its destruction by friction. The most promising and technologically advanced (but at the same time overly expensive) ADR programs include the use of space lasers or the deployment of wire ropes and slings to drag objects. In this sense, the European Space Agency (ESA) has already committed itself to promote further initiatives: the first concerns a project carried out by CleanSpace, consisting in the examination of technologies for advanced image processing, complex guidance, navigation and control and innovative robotics, aimed at capturing debris in orbit. The second initiative is a controlled deorbit action, called eDeorbit, which could be the first ESA-led ADR mission to remove large space debris from occupied orbit for controlled re-entry into the atmosphere.
Although space debris removal measures are useful to ensure the sustainability of space activities, they may not always be entirely lawful. Article VIII of the 1967 Outer Space Treaty (OST) states that the State of registry has exclusive jurisdiction over space objects; thus, States retain both jurisdiction and control over objects launched into space.
Conversely, no treaty has ever stipulated that control and jurisdiction disappear if space objects cease to function or are destroyed; the States of registry, therefore, continue to exercise their powers of control and jurisdiction over space debris.
The same applies to the ownership of space debris. One might wonder whether the State of registration might really be interested in maintaining ownership over these objects. In this respect, it has to be taken into account that even inactive space objects, such as space debris itself, may contain sensitive information or technologies whose intellectual property is to be preserved.
Having referred to space debris mitigation and removal measures, let us now consider the hypothesis in which a State is not interested in implementing them. Surely, in such a case, one or more third States might be concerned that the unremoved space debris might cause some harm to their own space activities. What alternatives would there be when faced with the presence of one or more hazardous space debris? The third States could try to obtain prior consent for the removal of space debris from the State registry. Another option would be to request the transfer of the registration of the satellite from which the debris originated.
If these options are not feasible, could the removal of this dangerous space debris finally proceed? In order to avoid incurring any kind of international responsibility, anyone who has reasonable grounds to believe that satellites they have launched into orbit may be adversely affected by a satellite that is no longer operational or by portions of it (space debris) may have recourse to the instrument of prior international consultations provided for in Article IX of the OST. The purpose of these consultations would be to convince the State of registry of the hazardous debris to implement appropriate removal measures. However, the long timeframe of such an international confrontation could exponentially increase the probability of a collision; therefore, if the risk of immediate damage or destruction proves to be well-founded, the State of registration of the hazardous satellite would be entitled to invoke the state of necessity and proceed to the immediate removal of the hazardous debris, proceeding in self-defense of its own interests. It should be borne in mind that this applies only to debris demonstrably from a registered satellite. Therefore, especially for smaller space debris, anyone would be entitled to proceed to the removal.
It also follows from the current legal regime for space activities that States are obliged both to provide for the disposal of the space debris produced and to verify that private companies do the same (Article VI of the OST). If this were not the case, the State of registration would be internationally responsible for any damage caused.
Despite the increasing size of satellite constellations and the resulting risks for space debris mitigation and removal, a new market opportunity for service provision is emerging. This is demonstrated by the investments of the Space Alliance (Thales Alenia Space and Telespazio) in the Canadian NorthStar Earth and Space project for a satellite constellation with dual function: Earth observation and space debris tracking directly from orbit. Moreover, D-Orbit is developing commercial debris activities as well as propulsion solutions for satellites and in-orbit services. This company aims to ensure safe and sustainable access to space by studying and developing in-orbit services and expanding in this specific area.
Where space debris clearly represents a critical issue to be kept monitored and controlled with the support of soft law instruments, it also represents an excellent investment and market opportunity, which will lead to the development of technologies and the implementation of innovative ways to safeguard space activities.