NEOShield Final Report: A global approach to near-Earth object impact threat mitigation

Abstract

NEOShield was conceived to address realistic options for preventing the collision of a naturally occurring celestial body (near-Earth object, NEO) with the Earth. Three deflection techniques, which appeared to be the most realistic and feasible at the time of the European Commission’s FP7 call in 2010, form the focus of NEOShield efforts: the kinetic impactor, in which a spacecraft transfers momentum to an asteroid by impacting it at a very high velocity; blast deflection, in which an explosive, such as a nuclear device, is detonated near, on, or just beneath the surface of the object; and the gravity tractor, in which a spacecraft hovering under power in close proximity to an asteroid uses the gravitational force between the asteroid and itself to tow the asteroid onto a safe trajectory relative to the Earth. Detailed test-mission designs are a primary product of the NEOShield project, and are intended to enable rapid development of actual test missions at a later stage. The report contains a brief description of highlights from the scientific and technical work packages of the NEOShield project, following the logical structure of the project: starting with scientific results from investigations of NEO physical properties, through target selection for deflection test missions, the monitoring of a deflection attempt, post-deflection orbit evolution, to the results from the technical work packages concerned with the design of feasible deflection test missions, and tools for an international strategy or “roadmap” for responding to an impact threat. A full list of resulting NEOShield scientific and technical documents ("deliverables") is appended to the report.