Approaches to the orbital debris problem so far have focused on minimizing the creation of new debris from launch and spacecraft operations, and on tracking what is already in orbit. Eventually, active debris removal will be employed as a result of advancing capabilities and increasing hazards. Researchers at NASA and elsewhere have found that the debris population, particularly in low Earth orbit, would continue to grow due to on-orbit collisions even in the absence of future launches.
The researchers calculate that the only way to stabilize the debris population is through a combination of strong adherence to existing mitigation guidelines (which has not been achieved yet) and active removal of at least five objects per year that have relatively large mass and high probability of collision. Modeling techniques have been used to create a list of hundreds of objects among the existing population that would be priority targets for retrieval. But even if we overcome the technical and economic challenges of debris removal, there are still law and policy issues that present obstacles.
Government and commercial entities contemplating debris retrieval can’t undertake salvage operations comparable to those performed in the oceans because the Outer Space Treaty of 1967 grants perpetual ownership of space objects to the launching state, even after the objects are deactivated and become uncontrolled junk. This makes it extraordinarily difficult to orchestrate a campaign to target the removal of high-priority objectives because permission must be obtained on a case-by-case basis from multiple foreign governments. This would be an expensive and time-consuming process that could undermine the feasibility and effectiveness of such a project. If the parties to the Outer Space Treaty are unwilling to update its language, as most of them seem to be, then this will remain a hindrance to a modern approach to salvage in space.
Fortunately, a remedy may be available under another multilateral space treaty: the Registration Convention of 1975. Article 4 requires signatories to provide a basic set of information to a U.N. registry after the launch of a space object. It also requires notification when an object has deorbited. There is no requirement to report anything about the object during its time on orbit. But although it’s not required, signatories may provide input during the on-orbit life of a space object. Article 4 states, in part, “Each State of registry may, from time to time, provide the Secretary-General of the United Nations with additional information concerning a space object carried on its registry.”
The nature of the “additional information” is not specified in the convention. One possibility would be notification of a change of ownership through a commercial or intergovernmental transaction, transferring the responsibility for a satellite to a different nation. Another possibility, one that would be very helpful to debris remediation planning, would be notification that an object, though still in orbit, is no longer in use and is not expected to be reactivated by its operator.
If the convention’s signatories agree that action is needed to enable debris cleanup, they could create a separate category in the registry for expired satellites and rocket bodies, labeling them “available for salvage.” As remediation techniques become available, signatories could be encouraged to put their space objects on the “available for salvage” list as they expire. In doing so, they would signal that “if you haul it away, it’s yours” but would retain ownership responsibilities until a successful retrieval mission was performed. If an object is salvaged, then the original owner is relieved of responsibility (and potential liability) for that object; if no retrieval is attempted, the outcome is no different from the current situation.
More detailed considerations would need to be worked out as this process is established, such as: At what point is ownership and liability transferred to the salvager and its host nation (e.g., first contact in orbit or completion of retrieval mission)? Is this accomplished by prior arrangement between countries, or specified in a license and/or contract if a private entity is involved?
All interested parties should have access to the salvage list. Governments and commercial entities willing and able to attempt retrievals should be encouraged to report in advance to the U.N. registry any intended retrievals to avoid conflicts between pursuers of the same object. Salvage targets should not be reserved for a particular operator — at least, not until a retrieval mission is under way — because this could lead to a situation similar to the “paper satellites” problem at the International Telecommunication Union, in which reservations are granted for actions that will never be completed.
Launching states would be under no obligation to put their satellites on the salvage list. Sensitive national security assets, or satellites that the launching state intends to retrieve or service itself, would retain the traditional space object ownership status. However, launching states that have assets on a high-priority retrieval list (objects that have relatively high mass and high probability of collision) should be encouraged by treaty adherents to make them available for salvage.
If the signatories of the Registration Convention support this new procedure in the interest of promoting debris cleanup, and experienced spacefaring nations like the U.S. and Russia set an example by making their expired satellites available, then salvage in space can be enabled without amending the Outer Space Treaty. Informal discussions with U.S. State Department colleagues have identified no obvious showstoppers to this approach, although it is clear that it would take several years to initiate. Therefore, we should start the process soon, not wait until retrieval missions are ready to be launched.
If the salvage list procedure is employed, the practice of satellite retrieval can become accepted as the norm and be added to the business plans of organizations contemplating satellite repair and refueling services. Companies can remove debris hazards from orbit as a service to governments and commercial operators. Eventually, they can expand the market for used satellites by performing on-orbit refurbishment and offering bargain-priced pre-owned spacecraft to customers who may not be prepared to purchase or wait for new ones.
Overcoming the space salvage legal hurdle is only part of the problem. Another key concern is the proliferation of proximity operations in space. Civil and commercial operators worry that proximity ops could accidentally damage or destroy valuable space assets. National security operators worry that damage or destruction could be intentional, and would prefer that no one else had the ability to conduct precision tracking, rendezvous and grappling of their satellites.
Such concerns are understandable, but let’s face the facts. The spacefaring community is growing in size and capabilities. If space development is to advance beyond the very basic operations that have been developed over the past half-century, it will be essential for active spacefarers to deploy manned and/or robotic systems that can approach, capture, repair, refuel, assemble, dismantle, reboost or deorbit a wide variety of hardware throughout cislunar space. If that doesn’t happen — if we try to prevent it from happening — then we have decided, in effect, to halt the further development of space. In contrast, if we want to move ahead, the global community must recognize the essential role of proximity ops and establish behavioral norms that dispel fears and tensions. Just as with aircraft, ships and ground vehicles that transit the globe, it would be unwise to ban or excessively restrict these activities just because they have the potential to function as weapons.
An important step would be the development of guidelines for proximity ops in space analogous to the orbital debris mitigation guidelines that are widely accepted today. Like the debris mitigation guidelines, this would be a years-long process that could start with the U.S. and other experienced spacefarers and from there seek general acceptance through a forum such as the U.N. Committee on the Peaceful Uses of Outer Space, or as an addendum to the European Union’s proposed space code of conduct. If successful, the effort could prove its value in promoting growth in commercial space activities, reducing the debris threat and easing tensions regarding international behavior in space.
The U.S. could initiate this process by crafting its own guidelines and incorporating them in licenses issued to U.S. private-sector entities planning proximity operations — a first step toward establishing a global norm. At a minimum, the guidelines could include:
- Prohibition against interference with satellites that have not been offered up for salvage.
- Prior public notification of launch or orbital maneuvers to initiate satellite servicing and retrieval missions.
- Prior notification to satellite owners of proximity operations within a specified distance (such as a few kilometers) of their space assets.
- Immediate alert of any servicing or retrieval mission that does not go as planned and may create a hazard for others.
The benefits of debris cleanup — and all the other capabilities that the same technologies bring — outweigh the risks of proximity ops. As more nations become spacefarers and orbital traffic increases, emerging players will not tolerate it if the established players try to limit their activities because their on-orbit operations are not trusted or because the orbits are deemed too full of debris. Rather, the space lanes will need to be tended by a conscientious global community in a coordinated effort to keep them safe for operations, in the best interests of all players. Active removal of derelict spacecraft and other debris will have to be part of that effort in the not-too-distant future. Responsibility for coordination of the retrieval efforts may reside with existing international organizations, but also could be managed by an international business collective akin to the Satellite Data Association, which has proved that critical operational issues affecting both government and nongovernment actors can be addressed through cooperation among competitor-colleagues.
James A. Vedda is a senior policy analyst at The Aerospace Corp. in Arlington, Va., and author of “Choice, Not Fate: Shaping a Sustainable Future in the Space Age.” The opinions expressed here are his own.