After DART: Using the first full-scale test of a kinetic impactor to inform a future planetary defense mission Articles uri icon



publication date

  • October 2022

start page

  • 1

end page

  • 18


  • 10


  • 3

International Standard Serial Number (ISSN)

  • 2632-3338


  • NASAs Double Asteroid Redirection Test (DART) is the first full-scale test of an asteroid deflection technology. Results from the hypervelocity kinetic impact and Earth-based observations, coupled with LICIACube and the later Hera mission, will result in measurement of the momentum transfer efficiency accurate to 10% and characterization of the Didymos binary system. But DART is a single experiment; how could these results be used in a future planetary defense necessity involving a different asteroid? We examine what aspects of Dimorphos's response to kinetic impact will be constrained by DART results; how these constraints will help refine knowledge of the physical properties of asteroidal materials and predictive power of impact simulations; what information about a potential Earth impactor could be acquired before a deflection effort; and how design of a deflection mission should be informed by this understanding. We generalize the momentum enhancement factor beta, showing that a particular direction-specific beta will be directly determined by the DART results, and that a related direction-specific beta is a figure of merit for a kinetic impact mission. The DART beta determination constrains the ejecta momentum vector, which, with hydrodynamic simulations, constrains the physical properties of Dimorphos's near-surface. In a hypothetical planetary defense exigency, extrapolating these constraints to a newly discovered asteroid will require Earth-based observations and benefit from in situ reconnaissance. We show representative predictions for momentum transfer based on different levels of reconnaissance and discuss strategic targeting to optimize the deflection and reduce the risk of a counterproductive deflection in the wrong direction.


  • Aeronautics
  • Fusion
  • Industrial Engineering
  • Mechanical Engineering
  • Physics


  • asteroids; near-earth objects; asteroid satellites; asteroid surfaces; impact phenomena