Terrestrial, maritime, and aerial travel have matured dramatically over the past century. National rules and international treaties create clear operational and territorial frameworks to regulate traffic, minimize collisions and ensure efficiency, economy, and sustainability in the movement of people and goods. Outer space is different – it belongs to no one and, therefore, belongs to everyone. Creating and enforcing laws and regulations across countries is difficult.
Space travel was complex and expensive two decades ago, dominated by powerful nation-states like the USA and the USSR. The number of missions was few and trackable, and space congestion was not a problem.
Fast forward to the present – more nation-states that want to explore space are emerging – players like China, India, United Kingdom, Japan, South Korea and European Union countries are launching new missions and satellites for applications ranging from navigation, communications and weather prediction to mapping forests for carbon offset trading. The commercial sector is vibrant – dominant, well-funded players like SpaceX and Amazon are launching constellations of thousands of satellites for communications. Venture-backed companies offering services ranging from refueling and maintenance to debris mapping and removal are emerging and, in many cases, supporting the efforts of national space programs. This expansion has been made possible as space missions’ costs and timeframes have dramatically reduced, primarily due to commercial players entering the fray and the decreasing costs of rockets, satellites, and sensors. Along with this come other challenges. A recent report by the Rand Corporation argues that we have reached a tipping point in space congestion and suggests how the space community can learn to cooperate based on experiences in the maritime, airline, communications, and financial transactions domains.
While larger satellites operate in MEO (Medium Earth Orbit, 2,000-35,786 km from Earth) and GSO (Geosynchronous Orbit, > 35,786 km from Earth), the congestion problem is most acute in LEO (Low Earth Orbit, 100-2,000 km from Earth). Operating in LEO can often be done with smaller payloads and lower launch costs and presents significant business opportunities for communications, mapping, navigation, positioning, manufacturing research and space services. The 3000+ satellites currently comprising the Starlink constellation (operated by SpaceX to deliver data connectivity to over 40 countries) are in LEO. Amazon plans to launch ~3000 satellites in LEO and offer internet connectivity as part of Project Kuiper, starting in 2024. The number of such satellite networks is expected to grow over time as different global players enter the fray. China announced plans in early 2023 to launch a 13,000 satellite network to provide internet connectivity, compete with SpaceX’s Starlink network, and, more recently, a plan to launch a second network of 13,000 satellites.
LEO is getting crowded. Over the past decade, the annual number of satellites launched has increased dramatically from 50 in 2010 to 2.5K in 2022. Figure 2 indicates this acceleration is primarily due to the growth of commercial communication satellites.
Based on planned and funded satellite programs currently, Inmarsat estimates that by the end of this decade, 100,000 satellites will populate LEO orbits. Congestion and risks of collisions are real at this point and magnified due to the absence of mutually agreed upon operational protocols between governments and commercial entities. As satellites reach end-of-life, collisions create ever-increasing levels of space debris (defined as artificial vs. natural objects). Debris is also generated by rocket bodies that launch the satellites and parts that peel away from the main satellite or rocket body due to planned or unplanned events. Based on a recent report by ESA on space debris, as of August 11, 2023:
- # rocket launches since the start of the space age in 1957: ~ 6410 (excluding failures)
- # satellites placed into Earth orbit: ~ 15760, ~10550 still in space, 8400 functioning
- # debris objects regularly tracked by the Space Surveillance Network catalog (operated by the United States Space Force): ~34490. More than 50% of these are in LEO.
- # Space debris objects estimated (based on statistical models) to be in orbit:
> 10 cm in size: 36,500
1-10 cm in size: 1 million
1-10 mm: 130 million
Debris caused on earth due to collisions is tragic in terms of human lives. However, it can be cleared and disposed of effectively without impacting ongoing operations or the environment. Debris in space remains there forever (unless removed) and risks creating more collisions and high-velocity debris that can cause severe damage to operational payloads. The impact on life on Earth is significant since space satellites drive critical activity ranging from positioning and timing to communications and financial transactions. Security on Earth relies on security and sustainability in space.
Secure World Foundation is a non-governmental organization whose mission is to “work with governments, industry, international organizations, and civil society to develop and promote ideas and actions to achieve the secure, sustainable, and peaceful uses of outer space benefitting Earth and all its peoples.” It recently organized the 5th Summit for Space Sustainability (June 13-14, 2023) in Manhattan, New York City. Five hundred attendees spanning government entities (United States, United Kingdom, European Union, Canada, Luxembourg, Nigeria and the United Nations), large business organizations (Amazon, Viasat), space tech investors and start-ups (ClearSpace, Digantara, Leo Labs, Astroscale and others). The themes addressed included the importance of space sustainability, governance models, venture investments, security and business opportunities presented by the increase in space travel and deployments. Dr. Peter Martinez is the Executive Director. A member of the International Academy of Astronautics, the International Institute of Space Law and a Fellow of the Royal Astronomical Society, he has a background in multilateral space diplomacy, policy formulation and regulation. He makes the following important points about space sustainability:
- Space is becoming more congested with active satellites, more contaminated with space debris, and more contested by governmental and non-governmental actors.
- Unlike transportation by cars, ships and planes, space has no internationally agreed rules or protocols for communications between vehicles launched by different entities. Establishing rules of orbit and information exchange is critical.
- The issue of space sustainability is like pollution prevention and mitigation on Earth. In space, debris is the “pollutant” that needs to be managed.
- Mission design should ensure no debris generation and a means to dispose of the payload safely and environmentally friendly at end-of-life. Disposal by burning up in the atmosphere may ultimately not be a sustainable practice as space activities accelerate in the future.
- ESG (Environment, Social and Governance) needs to be designed into missions and their operation. Government agencies should mandate this of players launching from their jurisdictions and looking to exploit business opportunities in their countries.
- Autonomous collision avoidance technology using sensors and propulsion systems exists– however, it consumes energy and reduces useful mission lifetime. In the future, it needs to be part of new mission designs.
- ASAT testing activity that generates debris should be eliminated.
- Continuous position monitoring of payloads and debris is critical.
- Space services have a significant role– from refueling, maintenance and other life-extension services to debris mapping and removal.
ESA (European Space Agency) is an active space player and progressive in space sustainability efforts, including debris management. It has identified ADR (Active Debris Removal) technologies as a strategic goal. Holger Krag leads ESA’s Space Safety Program based in Darmstadt, Germany. He lists two principles espoused by the IADC (The Inter-Agency Space Debris Coordination Committee, an international forum for the worldwide coordination of activities related to the issues of artificial debris in space) related to mission end for space deployments:
- Deplete all energy sources on board safely to avoid explosions that can cause debris.
- Ensure that satellites and launch rockets are disposed of and moved out of densely populated regions in space after the completion of their mission,
According to Mr. Krag, all players try hard to satisfy these conditions. Still, it is difficult to achieve in many cases (for example, if aging failures cut off remote command and control capability). Autonomous de-orbiting technology can be developed and added to satellites before launch. They would provide redundancy for the communication and propulsion systems, making a successful disposal maneuver possible. In addition, ESA believes that ADR is a reasonable measure to activate in cases where self-disposal is unsuccessful. ESA supports commercial ventures to develop ADR and de-orbiting technologies. Mr. Krag believes that if principles of autonomous de-orbiting and ADR become mandatory, insurance companies will have a significant role in providing products that enable the systematic use of such technologies.
JAXA (Japanese Aerospace Exploration Agency) also views space debris as an important issue and is actively working with commercial companies to develop solutions. The United States Space Force is targeting space refueling technology to increase mission life and provide sufficient onboard energy for sustainable disposal at end-of-life. Finally, the FCC (Federal Communications Commission, an agency of the United States) just released a rule that requires sustainable removal via deorbiting of satellites within five years of mission completion, which will “mean more accountability and less risk of costly collisions that increase debris.” Before this rule, the recommendation was to remove defunct satellites within 25 years, a period that is difficult to track and impractical given the growth of space activity.
The commercial focus on outer space is exciting. Innovation in space-based services is accelerating, led by prominent players like Amazon and SpaceX and emerging venture-backed startups. Establishing clear rules of orbit and space travel that ensure sustainability and safety as space traffic accelerates is critical. A proactive mission design that eliminates debris generation and uses debris mapping to plan safe orbital routes is necessary for safe, productive and profitable endeavors. Government agencies, regulators, insurance providers and commercial companies have a role to play as the space economy grows in the next decade.
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