Astrophys. Space Sci. Trans., 6, 41-48, 2010
www.astrophys-space-sci-trans.net/6/41/2010/
doi:10.5194/astra-6-41-2010
© Author(s) 2010. This work is distributed
under the Creative Commons Attribution 3.0 License.
 
07 Dec 2010
Moving an asteroid with electric solar wind sail
S. Merikallio and P. Janhunen
Finnish Meteorological Institute, Po. Box. 503, FIN-00101, Helsinki, Finland

Abstract. The electric solar wind sail (E-Sail) is a new propulsion method for interplanetary travel which was invented in 2006 and is currently under development. The E-Sail uses charged tethers to extract momentum from the solar wind particles to obtain propulsive thrust. According to current estimates, the E-Sail is 2-3 orders of magnitude better than traditional propulsion methods (chemical rockets and ion engines) in terms of produced lifetime-integrated impulse per propulsion system mass. Here we analyze the problem of using the E-Sail for directly deflecting an Earth-threatening asteroid. The problem then culminates into how to attach the E-Sail device to the asteroid. We assess alternative attachment strategies, namely straightforward direct towing with a cable and the gravity tractor method which works for a wider variety of situations. We also consider possible techniques to scale up the E-Sail force beyond the baseline one Newton level to deal with more imminent or larger asteroid or cometary threats. As a baseline case we consider an asteroid of effective diameter of 140 m and mass of 3 million tons, which can be deflected with a baseline 1 N E-Sail within 10 years. With a 5 N E-Sail the deflection could be achieved in 5 years. Once developed, the E-Sail would appear to provide a safe and reasonably low-cost way of deflecting dangerous asteroids and other heavenly bodies in cases where the collision threat becomes known several years in advance.

Citation: Merikallio, S. and Janhunen, P.: Moving an asteroid with electric solar wind sail, Astrophys. Space Sci. Trans., 6, 41-48, doi:10.5194/astra-6-41-2010, 2010.
 
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