On Tuesday night, Nov. 23, NASA launched its Double Asteroid Redirection Test (DART) mission on a SpaceX Falcon 9 rocket. This first-ever mission focused specifically on planetary defense is designed to work out technologies for countering dangerous space objects. The spacecraft will travel millions of miles to smash into an asteroid, changing its orbit. Dimorphos, a football stadium-sized “moonlet” of the larger asteroid Didymos, is the target of the fall 2022 kinetic impact. It is expected that the impact will alter by several minutes the orbital period of Dimorphos around Didymos.
Although there are no currently known threats, most near-Earth objects have not had their orbits determined (or even been detected), although 90% of those of a size comparable to the one that ended the reign of the dinosaurs are believed to have been identified.
When it comes to menacing asteroids, time is of the essence. This test mission will take nearly a year to reach its target, and the change to the target’s orbit is puny. Nuclear explosives could be repurposed for planetary-defense missions, but what is really needed is a program for nuclear-powered rockets, capable of reaching locations within the asteroid belt within weeks, rather than a year.
International cooperation on such a mission for the common defense of humanity is essential to ensure the long-term healthy survival of the human species.
