T. Maindl,  C. TraxlerT. Ortner,  G. Paar,  C. Schäfer (2020)

Momentum Enhancement and 3D Visualization of the DARTKinetic Impact

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Lunar and Planetary Science Conference (LPSC) 2020


We study deflecting sub-kilometer sized potentially hazardous asteroids that may collide with Earth by deploying a kinetic impactor. The momentum delivered by theimpact of a spacecraft may sufficiently alter the asteroid’s orbit and henceforth avoid an impact with our home world.While near-Earth asteroids of this size are difficult to observe,theyare believed to be very common and to consist of a wide variety of materials with varying bulk densities.Apart from directly transferring momentum from the projectile to the target, post-impact effects of a ki-netic impact will cause material to be ejected from the impact site. This material will carry additional momen-tum and hence increase the target’s momentum after the impact, translating to a momentum transfer efficiency b>1 which is only weakly constraineddue to the un-known target material and porosity.In an effort to con-strain this bfactor, we studythe impact of aspacecraft onto an asteroid similar in size to the secondary body “Didymoon” of the binary near-Earth asteroid (65803) Didymos, the target of NASA’s Double Asteroid Redi-rection Test (DART1) and ESA’s Hera2mission con-cepts.We present results from simulations with our own 3D smooth particle hydrodynamics (SPH) hyperveloc-ity impact code. Depending on the impact angle and tar-get porosity, we find bfactors between 1.15 and 1.93, which is compatible with results obtained in a previous study and by others using various methods.Real-time analysis of the simulated impact process and the result-ing surface features will allow us to align simulation re-sults with observations of the ESA Hera mission, further constraining material and porosity parameters of the mission target.

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