A concept of hazardous NEO detection and impact warning system

摘要

In 2013, the well-known Chelyabinsk meteor entered the Earth's atmosphere over Chelyabinsk, Russia. It is estimated that the meteor exploded at altitude near 30 km, which damaged thousands of buildings and injured a thousand of residents. The estimated size of the meteor is approximately 20 m. Because the meteor approached to Earth from Sun direction, no ground-based observatories could not detect until the impact.Considering such situations, the paper proposes a concept to detect Chelyabinsk-class small Near-Earth Objects. The concept addresses a "last-minute" warning system of NEO impact, in the same manner of "Tsunami" warning.To achieve the mission objective, two locations are assumed for the space telescope installation point i.e., Sun-Earth Lagrange point 1, SELL and Artificial Equilibrium Point, AEP. SELL is one of the natural equilibrium points, on the other hand, AEP is artificially equilibrated point by Sun and Earth gravity, centrifugal force and low-thrust acceleration. The magnitude of the acceleration to keep AEP is sufficiently small near 1 au radius orbit around the Sun i.e., the order of mu m/s(2) which can be achieved by solar sail. Through some cases of numerical simulations considering the size of NEOs and detector capability, this paper will show the feasibility of the proposed concept.