Guest Blog: Saving Earth Orbit, One Piece of Junk at a Time


A decade ago, the notion of actively removing debris from Earth orbit (as opposed to natural atmospheric decay) was squarely in the science fiction category.  Conventional wisdom labeled it as too expensive and too difficult to bother with, mainly because space was big and it would never get “too crowded.”  It’s funny how events conspire to change our perception of things.  In late June of this year, the Obama administration released the new U.S. National Space Policy which states:

“The now ubiquitous and interconnected nature of space capabilities and the world’s growing dependence on them mean that irresponsible acts in space can have damaging consequences for all of us. For example, decades of space activity have littered Earth’s orbit with debris; and as the world’s space-faring nations continue to increase activities in space, the chance for a collision increases correspondingly.”

As with most human-created messes, a few very smart people saw this one coming.  In the late 1970’s, two influential NASA scientists, John Gabbard and Donald Kessler, laid the scientific groundwork for what became to be known as the “Kessler syndrome.”  They predicted that at some point in the future the population of human-generated space debris would hit a critical point where it would pose a greater risk to spacecraft than the natural debris population of meteoroids.  According to their models, large pieces of space debris would get hit by smaller pieces of debris, creating hundreds or thousands of new pieces of small debris which would then collide with other large pieces.  This “collisional cascading” process would increase the population of space debris at an exponential rate. 

Although it would not become the bleak scenario shown in the movie Wall-E, the Kessler Syndrome meant that space debris would significantly increase the risks and costs of operating in space and could make certain missions no longer profitable or safe.  At the time, the work of Kessler and Gabbard was seen as interesting, but only one possible future and not predestined.  The prevailing sentiment within the space community was that we wouldn’t let things get that bad, and there would be plenty of time to prevent the Kessler Syndrome.

The events of the last few years have shattered what remained of that naiveté.  A series of intentional and unintentional events, including the 2007 Chinese ASAT test and the 2009 Iridium-Cosmos collision, have brought the harsh reality into focus:  the Kessler Syndrome is real, it is happening, and if we haven’t hit the point of no return by now, we will soon.  Although new spacecraft are being built and operated in a more responsible fashion, especially with regard to proper end-of-life disposal, there is a huge legacy burden of five decades of satellites and rocket bodies to deal with.  Many of these rocket bodies have a tendency to explode years after they are placed in orbit.  Massive satellites, such as ESA’s Envisat, were not designed to be de-orbited.  And even maneuverable satellites like Galaxy 15 can still fail unexpectedly and become a hazard.

At the 5th European Space Debris Conference in spring 2009, scientists and debris researchers concluded that simply reducing the amount of space debris we create, known as debris mitigation, is not going to solve the problem. There is enough existing debris that even with no new launches, debris-on-debris collisions will continue to create more debris. The researchers concluded that active debris removal is necessary to ensure the long-term sustainability of Earth orbit, and that removing a few as five or ten of the most massive debris objects each year might be enough to stabilize the growth in debris population.

These conclusions prompted DARPA and NASA to jointly sponsor the first International Conference on Orbital Debris Removal, held in Virginia in December 2009.  This was followed by a similar conference in Russia in April 2010 and another at the headquarters of the French National Space Agency (CNES) in Paris in June 2010.  As an attendee at both the DARPA and CNES events, I can say that there were a lot of very interesting and promising techniques proposed for actively removing debris from orbit.  And there is a growing amount of interest from the private sector for what they see as a potentially lucrative business enterprise.

However, much of the discussion about active debris removal so far has been about physics and engineering, and very little discussion has taken place with regard to the policy, legal, and economic challenges.  Usually these challenges are mentioned only in passing by the scientists and engineers.  But these are extremely important aspects of orbital debris removal, and could make or break the whole enterprise.
I was one of the few who did talk about the legal, policy, and economic issues at the DARPA conference.  In my presentation, I highlighted a number of the most vexing non-technical issues:

-    What is space debris, as legally separate from valuable space objects?
-    Who decides which objects should be removed?
-    Who is allowed to remove what objects?
-    Who pays for the debris removal?
-    What are the intellectual property rights and restrictions?
-    Is that spacecraft headed towards my satellite an orbital debris removal vehicle or an anti-satellite weapon?

That last question is perhaps the most important.  While active debris removal is not an anti-satellite or “space weapons” activity, some of the same technologies being considered for removing debris also have anti-satellite applications.  Moreover, development of active debris removal technologies could be interpreted as an ASAT development program.

The new U.S. National Space Policy also states that “it is the shared interest of all nations to act responsibly in space to help prevent mishaps, misperceptions, and mistrust.”  Active debris removal is certainly an activity which, if done without proper communication, coordination, and transparency, could create mishaps, misperceptions, and mistrust.  And while the engineers and scientists have seized on the importance of this issue and are dutifully working on solutions, the same cannot be said of the policymaking and legal communities, many of whom still consider the concept of actively removing objects from orbit science fiction.  Thus the question remains: when will the non-technical communities get engaged, and will the non-technical issues prove more challenging than the engineering and physics?

Brian Weeden is the Technical Advisor for Secure World Foundation (SWF).  Brian has extensive experience in the technical and operations aspects of national security space, specializing on the integration and application of technical aspects of space to policy and law formulation.  As Technical Advisor, Mr. Weeden conducts research on global space situational awareness, space traffic management, protection of space assets, and preventing conflict in space.  Mr. Weeden’s research and analysis have been featured in numerous news articles, academic journals, presentations to the United Nations, and testimony before the U.S. Congress.  Before joining the Foundation, he served nine years on active duty as an officer in the United States Air Force working in space and ICBM operations.

From 2004 through 2007 he directed the U.S. Strategic Command’s Joint Space Operations Center (JSpOC) orbital analyst training program and developed tactics, techniques and procedures for improving space situational awareness.