Gravity Tractor

Gravitational tractor for towing asteroids, Edward T. Lu andStanley G. Love, Nature (subscription required)

“A spacecraft could deflect an Earth-bound asteroid without having to dock to its surface first. We present a design concept for a spacecraft that can controllably alter the trajectory of an Earth-threatening asteroid by using gravity as a towline. The spacecraft hovers near the asteroid, with its thrusters angled outwards so that the exhaust does not impinge on the surface. This proposed deflection method is insensitive to the structure, surface properties and rotation state of the asteroid.”