A Gravitational Tractor for Towing Asteroids

Astrophysics, abstract
Date: Tue, 20 Sep 2005
A Gravitational Tractor for Towing Asteroids
Authors: Edward T. Lu, Stanley G. Love

We present a concept for a spacecraft that can controllably alter the trajectory of an Earth threatening asteroid using gravity as a towline. The spacecraft hovers near the asteroid with thrusters angled outward so the exhaust does not impinge on the surface. This deflection method is insensitive to the structure, surface properties, and rotation state of the asteroid.

http://arxiv.org/ftp/astro-ph/papers/0509/0509595.pdf