Optimal trajectories for NEO deflection

This paper presents a semi-analytical solution of the asteroid deviation problem when a low-thrust strategy is adopted, with a tangential acceleration inversely proportional to the square of the distance from the Sun. The displacement of the Near Earth Object at the minimum orbit interception distance is computed straightforward through the proximal motion equations. Gauss' variational equations are averaged over one orbital revolution of the true anomaly to give the secular variation of the keplerian elements, while their periodic component is approximated through a trigonometric expression. The latitude and time formulation are described and their accuracy is assessed, by a comparison to the numerical integration of Gauss equations. The analytical approach allows also for a considerable saving in computational time. Finally a set of mitigation missions are presented, as an application of the algorithm proposed. Copyright IAF/IAA. All rights reserved.