The Space Debris Problem: A Case for Enforceable International Guidelines Which Protect the Common Heritage of Mankind

Richard Elkind[1]

In 1968, Garrett Hardin, an ecologist, published a highly influential article in Science, entitled “The Tragedy of the Commons.”[2]  This article, building on ideas dating back to ancient Greece and popularized by agrarian reformers since the eighteenth century, described a situation where multiple individuals, acting independently, and rationally consulting their own self-interest, ultimately depleted a shared limited resource despite the fact it was not in everyone’s long-term interest. 

Article I of the Outer Space Treaty boldly claims that the extraterrestrial realms—outer space, including the Moon and other celestial bodies—shall be “free for exploration and use by all States without discrimination of any kind, on a basis of equality,” and that “there shall be free access to all areas of celestial bodies.”[3]  Further, the exploration and use of extraterrestrial realms is declared as being the “province of all mankind.”[4]  This language effectively establishes an open access and free use regime of space, “making it a public good whose owner is everybody and nobody.  Several other tenets of the Outer Space Treaty confirm and elaborate the above regime.”[5]  Indeed, today most actors in space understand the extraterrestrial realms to be res communis.[6]  This means that space is considered open for use by all States, with no discrimination, on a firm basis of equality.[7]  Essentially, space belongs to both everybody and nobody, a massive commons for mankind. 

Not surprisingly, mankind has begun to deplete this shared resource.  Here, I will briefly address one problem in space law, space debris.  “Space debris” is a general term which refers to “all tangible man-made materials in space other than functional space objects.”[8]  Everything launched into outer space has the potential to become space debris.  Debris then includes, “spent satellites themselves, ejected instrument covers, upper stages (orbital transfer stages), fragments thereof, etc., that is objects which originate from what were functional space objects but which no longer serve a useful purpose.”[9]  This broad definition also includes leaking fuel and coolant droplets, paint flakes and microparticulate matter, as well as tools dropped during space walks and garbage dumped in outer space by manned space missions.  Space debris is also called space refuse, space junk, or space trash.[10]

Interestingly, no international legal instrument currently provides a definition for space debris, and none of the UN space treaties expressly mentions the term “debris.” The most likely cause of this omission is because when the space treaties were negotiated the importance of space debris was not recognized.[11]  Space debris, however, has become a very serious problem.  Currently, approximately 9,800 man-made objects are in orbit.[12]  Of this figure, only 600-700 are operational spacecraft, which leaves a staggering ninety-three percent of man-made objects orbiting the Earth as space debris.[13]  The annual rate of increase in space debris is approximately two percent,[14] but, at the 2009 European Air and Space Conference, University of Southampton, UK researcher, Hugh Lewis predicted that the threat from space debris would rise fifty percent in the coming decade and quadruple in the next fifty years.[15] 

The expected lifetime for debris can vary wildly, depending primarily on its location.[16]  In low Earth orbits for example, “the air drag on the upper reaches of the atmosphere will eventually cause the debris to decelerate and heat up so that it breaks up under friction, whereas in higher orbits the atmospheric drag is virtually nil.”[17]  Even if some debris does not remain in orbit very long, it represents a serious danger for spacecraft.  In lower orbits, debris travels at least at seven kilometers per second, so that the kinetic energy of a collision can be considerable.[18]  A collision brings additional risks and fears, as one collision will produce fragments that could trigger other collisions resulting in a “cascade” and the creation of a debris belt that would endanger any space object crossing into that orbit.[19]  For example, “in 2007, the Chinese army used a missile to destroy a defunct weather satellite, and earlier this year an Iridium communications satellite collided with a derelict Russian vehicle.”[20] In both cases “thousands of debris shards” were added to near-Earth space.[21] 

The danger lies mostly in objects moving at orbital velocity around the Earth, as they will circle practically indefinitely if not intentionally removed or redirected.[22]  Due to the extreme velocities debris moves at, a particle no more than one centimeter in diameter can easily incapacitate an entire functional satellite, and an even smaller piece of debris entering the body of an active satellite has the potential to trigger a fatal reaction.[23]

In response to this increasing problem, the UN General Assembly attempted to take action on December 22, 2007, approving a set of voluntary guidelines for the mitigation of space debris.[24]  These voluntary guidelines seek to limit debris released during normal operations, minimize the potential for break-ups during operational phases, limit the probability of accidental collision in orbit, avoid intentional destruction and other harmful activities, minimize potential for post-mission break-ups resulting from stored energy, limit the long-term presence of spacecraft and launch vehicle orbital stages in the low-Earth orbit region after the end of their mission, and limit the long-term interference of spacecraft and launch vehicle orbital stages with the geosynchronous Earth orbit region after the end of their mission.[25]  While this is an important first step, there is currently no enforcement mechanism, and I believe much more needs to be done. 

Enforcement measures would occur under the umbrella of space law.  Space law is a very modern field of regulation that encompasses both national and international law governing activities in outer space.  Arguably, the resources of space are infinite, and limited only by our ability to use them in a manner that is equitable and environmentally ethical to all nations.  To this extent, space law has embraced the common heritage of mankind principle which holds that defined territorial areas and elements of humanity's common heritage (cultural and natural) should be held in trust for future generations and be protected from exploitation by individual nation states or corporations.  The space debris problem, however, has the potential to severely harm the enjoyment future generations would gain from space.  That is, without strong, enforceable international guidelines, the space debris problem will greatly hinder our access to the infinite resources of space which are the “common heritage of mankind.”

To prevent Hardin’s “tragedy of the commons,” additional steps must be taken.  At present, the space-debris problem is a classic tragedy of the commons.  Earth’s orbital space is a common resource, with the benefit of any particular satellite launch going to the user and the cost of space debris being spread across numerous others.  However, this scenario is comparatively manageable, due to the fact that the number of users is small, and most of the behavior involved, e.g., the launching and management of satellites, is easily observed by others.  This suggests that enforceable guidelines are a real possibility.

Such guidelines will likely proceed in multiple stages.  Nations should first address mitigation and traffic control/collision avoidance measures.  More effort should be devoted to ensuring that spacecrafts’ initial orbits are chosen with an eye toward reducing the risk of collision and reducing the production of debris should a collision occur.  Second, space powers should agree to particular standards regarding what conduct is negligent for purposes of compensation under the Liability Convention.  As a good starting point, space powers should create a set of “best practices,” including such practices as boosting expiring satellites into safe orbits.  Even today, satellites can be, and sometimes are, made to vent residual propellant or use such propellant to boost them into safer orbits at the end of their lifetimes.[26]  Creating a “safe harbor” under the Liability Convention through the use of these best practices might encourage launching states to voluntarily adopt such practices. 

Finally, the guidelines should provide a legal framework for space salvage. Under such a framework, international organizations or for-profit enterprises might be empowered to recover debris in exchange for financial awards.  Some scholars have also proposed an international regime that would “tax” countries for debris cleanup based on the amount of material left in orbit.[27]  Under this scenario, a country could pay a certain fee per ton left in orbit, with the money earmarked for cleanup or to recompense those harmed. While such proposals remain purely academic, such an approach, if enforceable, could prove successful.

Solving the space debris problem will not be easy, but strong enforceable international guidelines are an essential component to solving the space debris problem and averting a tragedy of the commons.

[1] Richard Elkind is currently an appellate law clerk to the Honorable Arthur Roy of the Colorado Court of Appeals.  He is a graduate of The George Washington University and Cornell University Law School.

[2] Garrett Hardin, The Tragedy of the Commons, 162 Sci. 1243 (Dec. 13, 1968).

[3] Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies art.1, Jan. 27, 1967, 18 U.S.T. 2410, 610 U.N.T.S. 205.

[4] Id.

[5] Virgiliu Pop, Who Owns the Moon? - Extraterrestrial Aspects of Land and Mineral Resources Ownership 73(Springer 2008).

[6] Id. at 75. 

[7] Id.

[8] Lotta Viikari, The Environmental Element in Space Law: Assessing the Present and Charting the Future 31 (Frans G. von der Dunk ed., Leiden 2008).

[9] Id.  Besides man-made space debris there is, of course, also naturally occurring debris such as meteoroids.  Today though, man-made debris is what dominates our concern. 

[10] Id. at 32.

[11] Lyall, supra note 7, at 303.

[12] Viikari, supra note 8, at 34.

[13] Id.

[14] Id.

[15] Paul Marks, Space Debris Threat to Future Launches, New Sci., Oct. 28, 2009, available at

[16] Viikari, supra note 8, at 36.

[17] Id.

[18] Lyall, supra note 7, at 305.

[19] Id.

[20] Paul Marks, Space Debris Threat to Future Launches, New Sci., Oct. 28, 2009, available at

[21] Id.

[22] Viikari, supra note 8, at 38.

[23] Id.

[24] Lyall, supra note 7, at 301.

[25] Id. at 301–03

[26] See Jennifer M. Seymour, Containing the Cosmic Crisis: A Proposal for Curbing the Perils of Space Debris, 10 Geo. Int’l  Envtl. L. Rev.  891, 904-12 (describing debris removal and mitigation techniques).

[27] See generally GLENN H. REYNOLDS & ROBERT P. MERGES, OUTER SPACE: PROBLEMS OF LAW AND POLICY (2d ed. 1997) (describing international and American space law).