Speaker
Description
Deflecting a hazardous near-Earth object (NEO) away from Earth impact may be done using a variety of techniques. Deflections may be categorized according to whether they are designed to be accomplished, in principle, with a single action, or whether they are designed to require multiple actions spread across time.
An NEO might be deflected with a single kinetic impactor (KI) or a single standoff detonation of a nuclear explosive device (NED). Such single-action deflection is possible when the nature of the NEO’s orbit, the amount of warning time, and the NEO’s mass and strength are all such that 1) a single KI or NED is sufficient to give the NEO the velocity change (delta velocity or DV) required for deflection, and 2) the NEO’s mass and/or strength enable it to tolerate that amount of DV without unwanted fragmentation. If those criteria are not met, then a series of smaller DVs may be imparted to the NEO such that their total effect eventually deflects the NEO. There may be some weeks or months in between the applications of those multiple deflection DVs for various reasons, including allowing time to assess the effects of the previous deflection DV, and launch limitations. Such a multi-action KI or NED deflection campaign could span months or even years.
KIs and NEDs are examples of impulsive, or “fast push” deflection techniques that change the NEO’s velocity instantaneously. By contrast, “slow push/pull” deflection techniques apply a very small continuous acceleration to the NEO over a long period of time to accomplish the total deflection of the NEO. Such techniques include the gravity tractor (GT) and ion beam (IB) deflection. Their small accelerations typically require years or even decades to fully deflect an NEO.
Any multi-action deflection (impulsive or slow push/pull) gradually moves the NEO, in a premeditated manner, away from its original natural Earth impact location. This necessarily, in effect, aims the NEO at locations not originally directly threatened by the NEO, as part of the gradual process of fully deflecting the NEO. The newly threatened locations would be known in advance. Should the deflection mission campaign fail to complete the deflection for some reason, then the NEO and all of its destructive energy will be heading towards a particular location that was not originally naturally threatened—and the new location now threatened would have been known in advance rather than unpredictable.
In this paper we present an analysis of the legal and policy issues pertaining to multi-action NEO deflection, considering both impulsive and slow push/pull. Our analysis considers existing bodies of law and treaties, existing legal precedents and analyses, the motivations and intentions of the launching state(s), whether the launching state(s) had a single-action deflection or disruption option available (even if nuclear) but selected a multi-action deflection option anyhow for some reason(s), and more. Findings and conclusions will be discussed, aiming towards articulating an effective and appropriate legal framework for proper handling of multi-action NEO deflection options prior to being confronted with an actual emergency.