Free Space Debris and Other Threats From Outer Space by Joseph N. Pelton

weapons.
    Adhesives
    Technology
    In this approach very sticky adhesive balls composed of substances such as resins or aerogels would be “shot” on to large space debris so as to alter their orbits and to bring them down over time [21].
    Level of Readiness and Feasibility
    This system would be less expensive than many of the other approaches but requires actual in-orbit tests.
    Policy and Legal Concerns
    This approach probably does not raise specific space weapons concerns, but the international community would still likely wish spacecraft that would spray the aerogels to be deployed via a global sanctioned organization than have a particular country (even a civil space agency) carry out these operations.
    Ion Beam Shepherd Concepts
    Technology
    The concept would have a precisely focused hyper-velocity ion beam applied to a piece of space debris that would then “shepherd” the space debris to a controlled de-orbit [22].
    Level of Readiness and Feasibility
    This is still largely a theoretical concept that has been identified as a possible solution to the space debris problem by JAXA, ESA and academic researchers. It is 3–5 years away from in-orbit tests.
    Policy and Legal Concerns
    This approach seems to pose few major policy concerns other than the strong need to have international control over these systems and their operation. None of the proposed systems would be totally free of concerns and thus some agreed level of international control over the operations would likely be necessary to alleviate possible use of such systems as space weapons.
    Ways to Approach the Solution of the Space Debris Problem
    Regulatory Approaches
    Clearly any of the various ways forward will include a regulatory component. COPUOS has developed voluntary guidelines for orbital debris control and minimization. These have been developed in conjunction with the IADC that has provided an expert level of technical support. The SDA has also contributed quasi-regulatory concepts to the control of space debris. Nevertheless, there remains a need for better and stricter guidelines to control formation of debris. Certainly the removal of space debris has technical and economical challenges not likely to be solved by regulations alone.
    Vetting the Technological Approaches
    The current wide diversity of ideas about how to remove space debris suggests several things. It suggests that at this stage at least there is no clear “winning idea” about how this could be done and that all of the options now available are unproven and expensive. Many of the removal concepts give rise to a variety of concerns. The idea that there could be several demonstration projects to start the removal of the largest derelict objects thus makes a great deal of sense. Certainly there are particular concerns about the largest defunct space objects that if they were hit by orbital debris of any significant size could generate hundreds if not thousands of new space debris elements. The Galaxy 15 (pictured in Fig.  5.2 below) is just one of the large derelict space objects that might be considered prime targets for removal from geo orbit in addition to the efforts to remove debris from LEO. In this instance a low-thrust ion engine could accomplish such a mission to move the Galaxy to a graveyard orbit.
    Fig. 5.2
    The Galaxy 15 satellite now a major piece of orbiting space debris (Graphic courtesy of Boeing)
    The creation of a single international agency to carry out this task gives rise to a host of concerns. These concerns include: (i) the high likelihood of focusing on a single and perhaps ultimately the wrong technology; (ii) extremely high cost; (iii) and the problem of international agencies not necessarily being the best source of innovation, not likely to produce cost effective solutions, and most likely to seek to be self-sustaining even if their mission has been fulfilled. Today the most “competent” space agencies to deal with space situational awareness and