410 - What Did We Learn From Crashing Into an Asteroid on Purpose?
Program note: Episode 410 is an update of episode 224, which I recorded in October 2022. Episode 224 is provided below.
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Guests
Dr. Carolyn Ernst is a planetary scientist at the Johns Hopkins Applied Physics Laboratory (APL), specializing in the surface evolution of planets, moons, and small bodies. She has contributed to missions across the solar system and has extensive experience in imaging systems. Dr. Ernst helped NASA impact both a comet and an asteroid, serving as instrument scientist for the DRACO imager and a member of the investigation team on the Double Asteroid Redirection Test (DART) mission. She is currently on the science teams for Europa Clipper, Dragonfly, Hayabusa2, and Martian Moons eXploration (MMX) missions. She is also a member of the European Space Agency’s Hera mission team, which will return to the Didymos system for close-range characterization of the asteroids and the outcome of the DART impact.
Michelle Chen is a software systems engineer and project manager at the Johns Hopkins University Applied Physics Laboratory (APL) in Maryland. Her work centers on developing and integrating advanced technologies for spacecraft and prototype systems. Chen led the SMART Nav team for NASA’s Double Asteroid Redirection Test (DART) mission, where their autonomous navigation algorithm enabled the world’s first spacecraft impact with an asteroid for planetary defense. Her career spans multisector projects, including the development of advanced prosthetic limbs, optical navigation systems, data acquisition platforms, and missile simulations. Chen’s technical expertise includes real-time embedded software, image processing, control systems, and system-level integration.
Summary
The conversation explores the success and implications of NASA’s Double Asteroid Redirection Test (DART), the first mission designed to test whether a spacecraft could intentionally alter an asteroid’s trajectory. Engineers and scientists collaborated to send a kinetic impactor into Dimorphos, a small asteroid orbiting the larger asteroid Didymos, demonstrating planetary defense capabilities.
A key innovation was the spacecraft’s autonomous navigation system, which guided it during the final approach using onboard imaging from the DRACO camera. Because scientists had never seen Dimorphos up close, engineers relied on extensive simulations to prepare for unknown conditions. The mission exceeded expectations: instead of shortening the asteroid’s orbit by 7 seconds, it achieved a 33-second reduction, largely due to unexpected ejecta that amplified the impact force.
The discussion highlights how asteroid detection and tracking systems—coordinated by organizations such as the Minor Planet Center and international networks—identify potential threats, refine orbital predictions, and communicate risks. Early detection remains critical, as effective deflection requires years of preparation.
Beyond the technical achievement, the guests emphasize interdisciplinary teamwork, where engineers and scientists continuously exchanged insights and made compromises to balance navigation precision with scientific data collection. The mission underscores the importance of experimentation over theoretical modeling alone and serves as a powerful example of how collaborative, cross-disciplinary work can address global challenges while inspiring future generations in STEM.
The Essential Point
The mission’s core insight is that planetary defense is not theoretical—it is achievable—but only through early detection, real-world experimentation, and deep collaboration across scientific and engineering disciplines.
Social Media & Referenced
New York Times: NASA Smashes Into an Asteroid, Completing a Mission to Save a Future Day
D.A.R.T. project overview and impact videos