A new paper under peer review by the Chinese-language Journal of Deep Space Exploration lays out an ambitious plan to crash a spacecraft at Mach 26, or 20,000 mph, into a near-Earth asteroid to test new planetary defenses. The South China Morning Post reports that a team led by Li Mingtao, chief scientist for planetary defense at the China National Space Administration, is planning a mission even more ambitious than NASA’s Double Asteroid Redirection Test (DART). That mission would slam a spacecraft into 2015 XF261, an asteroid estimated to be about 30 meters wide, in either 2029 or 2030. It would deploy a small probe to monitor the collision and measure changes to the asteroid's orbit, shape, surface, and internal structure. It will help scientists better understand how – and when – a kinetic impactor spacecraft could be used to deflect an Earth-bound asteroid.