Presentation #409.01 in the session Planetary Defense! (iPosters).
A near-Earth object (NEO) that poses a threat to Earth must be characterized to understand the severity and consequences of the threat and to determine a course of action. Constraining asteroid properties such as orbit, mass, presence of binary objects, shape, rotational state, composition, internal structure, material properties, surface topology, and presence of dust/coma can help inform mitigation strategies. Flyby characterizations have several schedule and operational benefits for planetary defense, e.g., flexible launch windows, reduced propellant, less complexity. But questions remain about how well a flyby can measure planetary-defense-related quantities versus a rendezvous. This knowledge gap must be filled in order to mount the best response in the case of a real threat to Earth.
We created simulated spacecraft images to assess the ability of a flyby mission to characterize asteroid properties key to planetary defense. A half-size Bennu shape model was used as the target asteroid; additional asteroid shape models will be used in future assessments. Images were simulated for a range of spacecraft encounters that sampled a range of phase angles, closest approach distances, flyby speeds, and camera capabilities. With these synthetic image sets, we created shape models to calculate the asteroid’s size/volume, and assessed how well we could constrain the asteroid’s mass using flown and in-development gravity science methods. We conducted image analyses in the Small Body Mapping Tool (SBMT) to characterize surface properties of the synthetic NEO, including boulder distribution. The results from our simulated flyby datasets will then be compared to the published findings from rendezvous missions to identify whether the information gathered from our simulated flybys are sufficient to characterize an NEO threat for the purpose of exploring future mitigation techniques.