The Journal of the Astronautical Sciences has a special issue, “Navigating Asteroid Impact Hazards: Astronautics Strategies for Planetary Defense” (link.springer.com/collections/didcicgjgf), which I’ve written about before. The special “issue” keeps going into April (vol. 73 #2):
McMillan, R. S. Brucker, M. J. Lejoly, C. et al. SPACEWATCH Astrometry of Near-Earth Asteroids for Planetary Defense 34 s40295-026-00575-1
Barbee, B. W. Vavrina, M. A., Bull, R. et al. Space Mission Options for Reconnaissance and Mitigation of Asteroid 2024 YR4 35 s40295-026-00578-y
Spacewatch started as an asteroid search program. Given the improvements in other search programs, Spacewatch has since dedicated itself to follow-up (brightness and tracking) asteroid observations instead. Here, McMillan et al. brief us all on their follow-up program.
Brent Barbee is an experienced researcher on asteroid celestial mechanics and space mission planning, and quite handsome. Now, Barbee et al. give a paper on space mission options regarding asteroid 2024 YR4, once ranked a top threat among near-Earth asteroids. Numerous mission plans are judged on their feasibility: reconnaissance missions (both new builds, and diverting existing craft), and defense flights. If a reconnaissance probe had determined 2024 YR4 to be, in fact, a threat to Earth (both in trajectory, and in size), then a mission to deal with it would be called for. Barbee et al. ponder multiple types of those missions, too. Deflection missions (of multiple types) would nudge the body off its Earth-intersect course. And since the object is ~60 meters in size, it’s within our technology to also try a “robust disruption” mission (also known as PI- “pulverize it”).