Human exploration of near-earth asteroids

Due to a number of factors, including a recent U.S. presidential directive, the successful return of an asteroid sample by the Japanese spacecraft Hayabusa in 2010, and the high-visibility airburst impact event over Chelyabinsk, Russia, in 2013, scientific and exploration interest in near-Earth asteroids (NEAs) has never been greater. In particular, NASA and the Japanese and European space agencies have begun expending serious effort to discover and identify appropriate NEA targets for a wide variety of spaceflight activities, including both robotic and human missions. These missions are particularly attractive as they will yield an unprecedented amount of knowledge about the formation of the solar system, provide a stepping-stone approach for future human exploration missions to Mars and beyond, identify materials for in situ resource utilization (ISRU), and test techniques for deflecting potentially hazardous objects that threaten Earth.