Mission analysis for the ion beam deflection of fictitious asteroid 2015 PDC

• We perform a realistic asteroid deflection mission design.
• We respond to a very interesting “benchmark asteroid deflection problem”.
• We introduce, for the first time, the concept of asteroid impact point retargeting.
• We show that ion beam deflection is applicable to a very difficult asteroid.

Based on a hypothetical asteroid impact scenario proposed during the 2015 IAA Planetary Defense Conference (PDC), we study the deflection of fictitious asteroid 2015 PDC starting from ephemeris data provided by the conference organizers. A realistic mission scenario is investigated that makes use of an ion beam shepherd spacecraft as a primary deflection technique. The article deals with the design of a low-thrust rendezvous trajectory to the asteroid, the estimation of the propagated covariance ellipsoid and the outcome of an ion beam slow-push deflection starting from three worst case scenarios (impacts in New Delhi, Dhaka and Tehran). Displacing the impact point towards an extremely low-populated, easy-to-evacuate region, as opposed to full deflection, is found to be a more effective mitigation approach. Mission design, technical and political aspects are discussed.