<h2>AAS 99-105</h2>
<h2>Optimal Deflection of Earth Approaching Asteroids                                                                                                </h2>
<h4>B. Conway                                                                                                                                                                           </h4>
University of  Illinois, Urbana, IL                                                                                                                                       
<h2> Abstract </h2>
One method suggested for the prevention of the collision of an asteroid with the Earth is to dfelct it from its course, perhaps using the explosion of a nuclear weapon. Solving the optimal control problem to maximize explicitly the resulting miss distance of the asteroid is problematic. A two-stage approach is used in this work. The time to interception, for a given interceptor launch date, if first minimized and then the direction of the deflecting impulse is optimized to maximize the subsequent deflection. This should in principle yield nearly the optimal deflection. Results are presented for the case of deflection of a real Earth-approaching asteroid, 1991 RB.