Sustainable space – for all of mankind

Space sustainability is defined as the ability to maintain the space activities indefinitely long time. This is the key for development of all services associated with space technologies. It is widely recognized nowadays that the space stability is in danger. There are several reasons for that: the spiked number of launches, deployment of low-orbit constellations of tens, hundreds, and even thousands of satellites, the growing threat of chaotic collisions in orbit and the snowballing growth of junk debris.

Space activity is important for the humanity as one of the development factors of emerging and least developed countries because it stimulates their high-tech industry, education projects, digitalization of economy and promotion of modern services. Therefore, such countries should have the ability to pursue space activities today and in relatively distant future. However, if the space is full of junk, they will not have such ability. 

The amount of space junk in low orbit has reached frightening figures: of more than 36,500 space objects larger than 10 cm, only 6,800 are active satellites, and the remaining nearly 30,000 are space debris. There are about 1 million smaller debris objects — the size of 1 cm and larger — in the near-Earth space (see Fig. 1). The European Space Agency (ESA) documented an incident in which a 2-mm shard knocked out about 8 solar panel fragments totalling about 40 cm in size, causing a real deterioration in the spacecraft's power. 

(Fig. 1. Current situation with space debris in orbit, source: Astroscale/ESA/NASA)

Optimistic and pessimistic scenarios

ESA has made a forecast of the Low Earth Orbit (LEO) situation (see Fig. 2).

(Fig. 2. Forecast of the LEO situation, source: ESA)

If no action is taken to reduce space debris (the white line in Fig. 2), even in the absence of new launches, the number of debris in orbit will grow and inevitably there will be the Kessler syndrome – an avalanche-like increase in debris due to uncontrolled collisions, each leading to subsequent ones. If we retain only those measures to combat debris in near-Earth space that are being taken now, the situation will follow a very similar scenario (the red line in Fig. 2), and will still be unmanageable. If we eliminate one of the most serious causes of debris — explosions of objects (most often explosions of fuel residues in the upper stages of launch vehicles and correction propulsion systems, as well as incompletely discharged batteries of spacecrafts), it will be possible to slow the increase in space debris by about half. But still the problem will remain (the blue line in Fig. 2). The growth of the debris amount can be stopped, only if 100% of spacecrafts with expired active life time are removed from orbit, and nearly all (90%) upper stages of launch vehicles are disposed of (the green line in Fig. 2). If we add to this the active removal of already accumulated debris, there is a chance to gradually reduce the amount of junks in low orbits. 

How to regulate space "cleaning"?

Radio frequencies and satellite orbits are considered limited natural resources of space. In recent years, the geostationary and low orbits, which make up a significant portion of near-Earth space, have become especially in demand. While the International Telecommunication Union (ITU) regulates the use of the radio frequency spectrum and associated satellite orbits, there is currently no multilateral international coordination of space traffic in orbits. And it is highly needed, because only over the recent 4 years, the number of spacecrafts has doubled, and the humanity does not intend to reduce the rate of launching new satellites into orbit. But unlike the ITU, international organizations that are trying to address the issue of coordination of space traffic have no real mechanisms to influence the situation or the players. States bear international responsibility for national activities in outer space and liability for possible damage caused by satellites they launch. However, the current international agreements do not provide the obligation to remove inoperable spacecraft from orbit. Each state launches satellites following national rules as well. To ensure sustainable space, it is reasonable for such rules to include a mandatory assessment of the effects of a launched object into space. By monitoring national space activities and foreign players' access to the national market, regulators have the right to filter operators based on their adherence to the principles of sustainable space development. In this regard, it would be helpful for regulators to have a specialized versatile tool for the assessment of satellite systems, which currently does not exist.

The number of countries implementing their own space programs is growing. On the one hand, this is a positive factor — the space economy is starting to play a big role, and such states are particularly value the provision of sustainable space. On the other hand, national space programs do not always have the transparency required for situational awareness in space, especially when it comes to national defence and security systems.

Several UN forums, including the UN Committee on the Peaceful Uses of Outer Space and the Open-Ended Working Group on reducing space threats through norms, rules and principles of responsible behaviours, have been discussing a whole range of issues related to the sustainability of space activities. Intersputnik as an intergovernmental organization participates in discussions on both platforms.

The regulatory framework must have an economic basis

ESA proposes to introduce a special insurance fee for cleaning up space debris. By 2030, ESA intends to achieve neutrality: either all spacecraft will be able to be removed from orbit, or a contract will be signed with a company providing the relevant services. 

Situational awareness of events in space is the key to sustainability of space activities, but it has not yet been fully achieved. Economic measures can help to provide situational awareness. For example, today, a favourable market environment, in which data on the movement of spacecraft would acquire a tangible commercial value, is still partially formed – mostly among individual space actors from one state or countries cooperating in space.

It should be also noted that constant tracking of space objects locations and ensuring that they are fully controllable and manoeuvrable is a serious cost item for the operator. For example, OneWeb, with 450 satellites in orbit, analyses about 50,000 reports of possible collisions per day, and about 8 reports lead to orbital motion modification manoeuvres. Each of such manoeuvres requires some costs expenditures from the operator, ultimately affecting the final cost of services to consumers and the business success of the project as a whole.  Regulators can use economic measures, such as easier access to debt financing, lower rates on loans and insurance products, etc., to support operators in promoting the sustainability of space activities. Working with private and corporate investors to encourage what is called responsible investment – investing in space projects that meet the requirements of space activities – also has a special role to play.

Suggested technology options

In-orbit maintenance of active spacecrafts extending their operational lifetime, including refuelling and recharging, and active removal of expired spacecrafts that have not been deorbited are among the technologies under development that could contribute to improving the situation with space debris. By 2030, the volume of this market may reach $1 trillion if regulators and operators begin to act as one, but there is still no clear economy and no stable legal framework behind this technology. Competitors must learn to work together on a collaborative basis. OneWeb, SpaceX, and Iridium can be seen as an example. Competing in the satellite communications market, these companies are now developing joint principles for coordinated space traffic control. 

Experts point out that many of the rules, in particular the rules of navigation and aviation safety, were introduced after high-profile accidents, which we would like to avoid in space. However, the possibility exists because space debris in LEO can make flights to other orbits, including manned flights, dangerous or inaccessible. 

(Fig. 3. Recommendations for LEO-based systems by national regulators, source: Astroscale)

See recommendations for LEO-based systems by some national regulators in Fig. 3.

A number of experts suggest that each satellite on LEO should have a deadline to be removed from orbit after termination of its operation (e.g., five years) and that each satellite should have an engine or other system to avoid collision and move away from orbit after termination of service. However, in the development and implementation of any new rules, including those of a technical nature, the freedom of exploration and use of space, proclaimed by major international agreements in space, as well as the interests of developing and least developed countries embarking on space exploration, must also be taken into account. The new rules should be a reasonable balance between the interests of all participants in space activity, which is the heritage of all mankind.

It is also worth considering that if the owner of a single spacecraft in low orbit is subject to the same requirements as the owner of a constellation of 5,000 satellites, large constellations will gain a serious regulatory advantage.  Therefore, it is reasonable to calculate the cumulative probability of collision within a single system. If we try to summarize the opinions voiced by experts on the topic of space sustainability over the past year, there are several main points to be made.

First: commercial entities are seriously concerned about this topic, also following the growing trend of social responsibility of private companies and fearing the destruction of their business in low orbit. Government entities are also involved in the space sustainability debate, but the adoption of specific measures at the global level is stalled by the procedural complexities and formalities inherent in international standard-setting.

Second: proponents of strict regulation of the use of near-Earth space are concerned that all participants, without exception, are subject to these rules. They fear that some players may not adhere to the new regulation framework if it is advisory in nature, that could put players in different positions and upset the balance of the market. Proponents of the rejection of new technical restrictions fear that their implementation could become an artificial administrative barrier to access to space and the space business in particular.

The third point comes from the second: the interested entities are hastily looking for both a hypothetical stick and a hypothetical carrot. Under this scenario it will be possible to effectively direct the development of space activities in the direction of sustainability, similar to those that ensure the management of the use of radio frequency spectrum by any means of telecommunications around the world.