  This paper presents the design of a multi-spacecraft system for the
deflection of asteroids. Each spacecraft is equipped with a fibre laser and a
solar concentrator. The laser induces the sublimation of a portion of the
surface of the asteroid. The jet of gas and debris thrusts the asteroid off its
natural course. The main idea is to have a swarm of spacecraft flying in the
proximity of the asteroid with all the spacecraft beaming to the same location
to achieve the required deflection thrust. The paper presents the design of the
formation orbits and the multi-objective optimization of the swarm in order to
minimize the total mass in space and maximize the deflection of the asteroid.
The paper demonstrates how significant deflections can be obtained with
relatively small sized, easy-to-control spacecraft.
