6.1 International debris mitigation guidelines (IADC, UN)
5 min read•august 7, 2024
Space debris mitigation guidelines are crucial for ensuring sustainable space activities. International organizations like IADC and UN COPUOS have developed key guidelines to limit debris generation and promote responsible space operations.
These guidelines cover , including the and , as well as operational measures like collision avoidance and debris monitoring. They aim to reduce risks and preserve the space environment for future use.
International Organizations and Guidelines
Inter-Agency Space Debris Coordination Committee (IADC)
IADC is an international forum of space agencies that coordinates activities related to human-made and natural debris in space
Founded in 1993, it consists of 13 member agencies including NASA, ESA, JAXA, and Roscosmos
Aims to exchange information on space debris research activities between member agencies, facilitate opportunities for cooperation, and identify debris mitigation options
Develops and publishes guidelines for the mitigation of space debris, which have been used as the foundation for space debris mitigation standards adopted by other organizations (UN COPUOS)
United Nations Committee on the Peaceful Uses of Outer Space (COPUOS)
COPUOS is a committee within the United Nations that governs the exploration and use of space for the benefit of all humanity
Established in 1959 to review international cooperation in peaceful uses of outer space, encourage space research programs, and study legal problems arising from the exploration of outer space
Consists of 95 member states and is the primary international forum for the development of laws and principles governing space-related activities
In 2007, COPUOS adopted the Space Debris Mitigation Guidelines, which are based on the and provide a framework for space debris mitigation measures to be implemented by individual countries and international organizations
Space Debris Mitigation Guidelines
A set of internationally recognized guidelines for the mitigation of space debris, developed by the IADC and adopted by the UN COPUOS
Aim to limit the generation of space debris in the near-Earth environment by promoting responsible space operations and design practices
Key measures include limiting debris released during normal operations, minimizing the potential for on-orbit breakups, post-mission disposal, and prevention of on-orbit collisions
Guidelines are voluntary and non-binding, but have been widely adopted by space agencies and satellite operators worldwide as a standard for mitigating space debris
Post-Mission Disposal
25-year rule
Guideline stating that spacecraft and orbital stages should be designed to ensure their post-mission orbital lifetime is less than 25 years
Aims to limit the long-term presence of non-functional objects in low Earth orbit (LEO) and reduce the risk of collisions with active satellites
Achieved through various methods such as propulsive maneuvers, drag enhancement devices, or disposal orbits
Applies to objects in LEO, as objects in higher orbits (MEO, GEO) have much longer orbital lifetimes and require different disposal strategies
Passivation
The process of removing stored energy from a spacecraft or orbital stage at the end of its mission to reduce the risk of explosive breakup
Involves depleting propellants, discharging batteries, and venting pressurized systems
Helps prevent the creation of new debris fragments due to accidental explosions of defunct spacecraft
Required by most space debris mitigation guidelines and is considered a critical step in the post-mission disposal process
Orbital lifetime reduction
Techniques used to reduce the time a spacecraft or orbital stage remains in orbit after the end of its mission
Includes methods such as lowering the orbit to accelerate atmospheric drag decay, using propulsive maneuvers to move the object to a disposal orbit, or deploying drag enhancement devices (balloons, sails)
Aim is to comply with the 25-year rule and minimize the long-term presence of debris in heavily used orbital regions
Choice of method depends on factors such as the object's size, orbit, and available on-board resources (propellant, power)
Re-entry risk
The potential for a spacecraft or orbital stage to cause damage or injury during its uncontrolled re-entry into Earth's atmosphere
Determined by factors such as the object's size, material composition, and re-entry trajectory
Space debris mitigation guidelines require that the risk of human casualty from re-entering debris be less than 1 in 10,000
Controlled re-entries, where the object's trajectory and impact location can be predicted, are preferred for large or high-risk objects to minimize potential damage on the ground
Operational Mitigation Measures
Collision avoidance
The process of monitoring the trajectories of space objects and maneuvering active spacecraft to avoid potential collisions
Involves using ground-based and space-based surveillance networks to track objects and predict close approaches (conjunctions)
When a high-risk conjunction is identified, satellite operators can perform to adjust the spacecraft's orbit and reduce the probability of a collision
Requires accurate orbital data, timely conjunction assessments, and efficient decision-making processes to be effective in preventing collisions and the creation of new debris
Orbital debris monitoring
The continuous observation and tracking of space debris to maintain situational awareness and support collision avoidance activities
Conducted using a combination of ground-based radar, optical telescopes, and space-based sensors
Provides data on the size, shape, orbit, and material composition of debris objects, which is used to characterize the debris environment and assess collision risks
Major debris monitoring systems include the U.S. Space Surveillance Network (SSN), the European Space Surveillance and Tracking (EU SST) program, and the observation campaigns
Spacecraft shielding
The use of protective materials and structures to reduce the damage caused by impacts with small debris objects
Includes Whipple shields (thin outer bumper and spaced rear wall), multi-shock shields, and advanced materials such as Kevlar and ceramic composites
Designed to break up and disperse the impacting debris, reducing the penetration depth and damage to the spacecraft's critical components
Effective against small debris (millimeter to centimeter-sized) but cannot protect against impacts with larger objects, which require collision avoidance measures
Redundancy systems
The incorporation of backup components and subsystems in spacecraft design to maintain functionality in the event of a debris impact or other failure
Includes redundant power supplies, communication systems, on-board computers, and control actuators
Allows the spacecraft to continue its mission even if some components are damaged or lost due to debris impacts
Increases the overall reliability and resilience of the spacecraft, reducing the risk of mission failure and the creation of new debris from on-orbit breakups
Key Terms to Review (23)
25-year rule: The 25-year rule is a guideline established to mitigate space debris by requiring that objects in low Earth orbit (LEO) should not remain in orbit for more than 25 years after their mission has ended. This rule aims to reduce the risk of collisions and the creation of additional debris by ensuring that defunct satellites and rocket stages re-enter the Earth's atmosphere within this time frame, thus contributing to a sustainable space environment.
Active Debris Removal: Active debris removal refers to the set of technologies and missions designed to remove space debris from Earth's orbit actively. This process involves using various methods, such as robotic arms, nets, or harpoons, to capture and deorbit defunct satellites and fragments, thereby reducing the risk of collisions and ensuring the long-term sustainability of space activities.
Collision avoidance maneuvers: Collision avoidance maneuvers are strategic adjustments made by spacecraft to prevent potential collisions with space debris or other operational satellites. These maneuvers are crucial in maintaining the safety and integrity of spacecraft, ensuring they can continue their missions without the risk of damage from unexpected encounters in space.
Collision risk assessment: Collision risk assessment is the process of evaluating the likelihood of two or more space objects, such as satellites or debris, colliding in orbit. This assessment involves analyzing various factors, including the objects' trajectories, velocities, and any potential changes to their paths, to predict and mitigate the risk of collisions that can cause damage to space assets and increase debris.
Conjunction Assessment: Conjunction assessment is the process of evaluating potential collisions between space objects, including satellites and debris, to determine the risk of close approaches. This assessment is crucial for maintaining the safety of operations in orbit, as it involves tracking the trajectories of various objects and predicting their paths to identify potential conjunctions or close encounters. By analyzing these risks, stakeholders can take necessary actions to mitigate potential impacts on space assets.
Debris population models: Debris population models are analytical frameworks used to estimate and predict the amount, distribution, and behavior of space debris in Earth's orbit. These models are essential for understanding the risks posed by space debris to operational satellites and manned missions, as well as for informing guidelines aimed at mitigating debris generation and enhancing space safety.
Deorbiting: Deorbiting refers to the process of intentionally bringing a satellite or spacecraft back into the Earth's atmosphere, where it ultimately burns up or falls to the surface. This action is crucial for effective space debris mitigation, as it reduces the risk of space collisions and ensures that defunct objects do not remain in orbit, contributing to the growing problem of space debris. By managing deorbiting effectively, stakeholders can help protect both active satellites and the safety of future space missions.
Design for Demise: Design for demise refers to engineering practices that ensure spacecraft and satellites will burn up upon re-entry into the Earth's atmosphere, minimizing the risk of space debris creation. This concept emphasizes the importance of materials, structural design, and mission planning to facilitate safe disposal at the end of a spacecraft's operational life, thus addressing broader concerns about space debris and environmental sustainability in outer space.
End-of-life disposal: End-of-life disposal refers to the processes and methods used to manage spacecraft and satellite systems when they reach the end of their operational lifespan. This includes strategies to ensure that defunct satellites do not contribute to space debris, which can pose risks to active spacecraft and the sustainability of space activities.
IADC Guidelines: The IADC Guidelines refer to a set of international recommendations developed by the Inter-Agency Space Debris Coordination Committee aimed at mitigating space debris. These guidelines provide a framework for space-faring nations and organizations to reduce the creation of new debris and enhance the long-term sustainability of space activities. By promoting best practices in satellite design, operation, and end-of-life disposal, the IADC Guidelines play a crucial role in addressing the growing concern of space debris and its impact on orbital environments.
Inter-Agency Space Debris Coordination Committee (IADC): The Inter-Agency Space Debris Coordination Committee (IADC) is an international forum for space agencies to coordinate efforts in the area of space debris mitigation and research. It facilitates collaboration among member organizations to develop guidelines and strategies aimed at minimizing space debris, ensuring safe operations in space, and promoting sustainable practices in outer space activities.
International treaties on space debris: International treaties on space debris are agreements established among nations to manage and mitigate the growing issue of space debris in Earth's orbit. These treaties aim to provide guidelines for the responsible use of outer space, ensuring that space activities do not contribute to the increase of debris and that existing debris is effectively managed, thus promoting sustainable space exploration and utilization.
National space legislation: National space legislation refers to the legal frameworks established by individual countries to govern their activities in outer space, ensuring compliance with international treaties and addressing issues like liability, registration, and environmental protection. This type of legislation is crucial for promoting responsible behavior in space operations and aligns with international debris mitigation guidelines while also considering the procedures for safely decommissioning spacecraft and managing end-of-life considerations.
Orbital debris monitoring: Orbital debris monitoring refers to the systematic observation and tracking of space debris, which includes defunct satellites, spent rocket stages, and fragments from collisions or explosions in orbit. This process is crucial for assessing the risk posed by orbital debris to active satellites and human spaceflight, and it supports effective debris mitigation strategies outlined by international guidelines.
Orbital Lifetime Reduction: Orbital lifetime reduction refers to the process of decreasing the time that space debris remains in orbit around the Earth before re-entering the atmosphere. This is an important aspect of space debris mitigation, as shorter orbital lifetimes help minimize the risk of collisions and reduce the amount of debris that can accumulate in various orbits, thereby protecting both operational satellites and future missions.
Passivation: Passivation refers to the process of making a spacecraft component inactive or inert after its operational lifetime to minimize the potential for creating space debris. This involves depleting remaining fuel, discharging batteries, and ensuring that no unintentional explosions or fragmentation can occur, thereby contributing to efforts aimed at responsible space debris management.
Post-mission disposal: Post-mission disposal refers to the practices and strategies employed to safely deorbit or remove spacecraft and their components from orbit after their operational life has ended. This process is critical in preventing space debris, as it ensures that defunct satellites and other remnants do not contribute to the growing population of space debris that poses risks to active spacecraft and future missions.
Re-entry risk: Re-entry risk refers to the potential danger posed by space debris or defunct satellites re-entering Earth's atmosphere and impacting the surface. This phenomenon is critical to consider as it can result in property damage, injuries, or loss of life, highlighting the need for effective space debris mitigation strategies and compliance with international guidelines.
Redundancy Systems: Redundancy systems refer to backup components or processes incorporated into spacecraft to ensure continued operation in case of failure of primary systems. This strategy is critical for maintaining the reliability and safety of operational spacecraft, especially when considering the harsh environment of space and potential hazards from space debris. The implementation of redundancy can take various forms, such as duplicate systems or alternative pathways for data and power, which collectively enhance the resilience of spacecraft against unexpected failures.
Spacecraft design for debris mitigation: Spacecraft design for debris mitigation refers to the engineering practices and design principles aimed at reducing the creation and accumulation of space debris during and after the operational life of a spacecraft. This involves incorporating strategies that minimize the risk of collision, ensure safe deorbiting, and enhance the longevity of spacecraft components to limit their fragmentation, thereby contributing to the overall sustainability of the space environment.
Spacecraft shielding: Spacecraft shielding refers to the protective materials and designs used to safeguard spacecraft and their occupants from harmful space debris, radiation, and other hazards encountered in space. Effective shielding is essential for ensuring the longevity of satellites and human-rated vehicles, while also adhering to international guidelines that aim to mitigate space debris.
UN space debris mitigation guidelines: The UN space debris mitigation guidelines are a set of international recommendations aimed at minimizing the creation of space debris and ensuring the sustainable use of outer space. These guidelines help countries and organizations manage their activities in space, addressing issues such as satellite end-of-life disposal, collision avoidance, and the long-term sustainability of space operations.
United Nations Office for Outer Space Affairs (UNOOSA): The United Nations Office for Outer Space Affairs (UNOOSA) is a specialized agency of the United Nations responsible for promoting international cooperation in the peaceful use of outer space. UNOOSA plays a key role in the development and implementation of international space law and guidelines, including the International Debris Mitigation Guidelines aimed at reducing space debris and ensuring sustainable space activities.