A comparative assessment of different deviation strategies for dangerous NEO
- Paper number
IAC-06-A3.5.08
- Author
Ms. Camilla Colombo, University of Glasgow, United Kingdom
- Coauthor
Dr. Massimiliano Vasile, University of Glasgow, United Kingdom
- Coauthor
Mr. Joan Pau Sanchez Cuartielles, University of Glasgow, United Kingdom
- Coauthor
Dr. Gianmarco Radice, University of Glasgow, United Kingdom
- Year
2006
- Abstract
On average, every 26-30 million years a 10 km sized asteroid will strike the Earth, while every 100 years a Tunguska class (100 m in size) asteroid will hit. Each of these impacts permanently alters the characteristics of our planet to varying degrees. These events, and risks associated to our fragile ecosystem, have made the space community turn their attention to Near Earth Objects (NEO) [see the outcome of the ESA Long Term Space committee, in May 1999]. Moreover recent astronomical observations, advances in orbit determination of asteroids and theoretical studies on hazard characterization have increased our capabilities of predicting potential impacts. The result of these studies has urged the scientific community to look into possible mitigation strategies. During these last few decades many deviation methods involving numerous physical interactions with the asteroid have been analyzed. These strategies can be organized in four main groups: kinetic impactors, i.e. methods modelled as inelastic impacts [W. J. Tedeschi, 1995; McInnes, 2004]; attached propulsion devices [Ivashkin and Smirnov, 1995] (e.g. electric/chemical engines, solar sails); induced thermo-optical changes on the asteroid surface [J.N.Spitale, 2002] (e.g. induced Yarkovsky effect, paints) and ablation methods [Melosh H.J, 2004] (e.g. lasers, solar mirrors). More recently, other advanced concepts have been considered such as gravitational tractors and technologies that act on the magnetic field or the rotational properties of the asteroid. Only a few authors have performed a partial comparative assessment of the numerous proposed mitigation strategies. Some of these emphasise a classification system based on NEO/spacecraft coupling [Christopher et al., 1997], other systems are based on technology readiness and a third category on time to impact and/or intervention of the asteroid [Canavan et al., 1992]. This paper presents a more exhaustive comparison of deflection methods according to different criteria. After a taxonomical classification of NEO physical characteristics (i.e. size, mass, shape and spin properties), composition (i.e. surface composition and heterogeneity, gas and dust emission) and orbital parameters (including inclination and eccentricity), the principal mitigation strategies have been evaluated in terms of several figures of merit: achieved miss distance at the Earth, anticipating time, total mass into orbit, estimated total cost of the mission and technology readiness (estimated time to develop the required technology). The miss distance, due to the variation in the orbital parameters given by each strategy, has been computed by means of proximal motion equations for elliptical orbits and projected onto the b-plane at the Earth. The anticipating time has been defined as the time difference between the impact epoch and the time a given strategy is applied. Finally the paper presents a multi-criteria optimization which provides a relative measure of the effectiveness of the different mitigation approaches.
- Abstract document
- Manuscript document
IAC-06-A3.5.08.pdf (🔒 authorized access only).
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