Detection system of near Earth objects based on the axial orbit in the Sun–Earth circular restricted three-body problem

Abstract

L4 and L5 axial orbits provide special locations to monitor and search for near Earth objects (NEOs) due to their offset locations. In this paper, we propose a detection system of NEOs on the axial orbit in the Sun–Earth circular restricted three-body problem. Taking the Sun exclusion zone into consideration, we design an observation strategy for space-based telescopes on axial orbits. Then, an observation accessibility measure for the motionless point is presented to evaluate the performances of the different axial orbits and formations. In addition, the detection performance of axial orbits is compared with the distant retrograde orbits (DROs) and Earth-displaced heliocentric orbits (EDHOs). Numerical simulations indicate that the detection performance of axial orbits for the motionless point is better than that of DROs but is inferior to EDHOs. On the other hand, the axial orbit is dynamical stable, but EDHOs are unstable and their fuel costs for maintenance cannot be ignored with the increase of service time. Furthermore, the detection system on axial orbits is applied to moving objects. For example, the detection system of the EDHOs cannot predict the Chelyabinsk asteroid impact, but it is possible for the DRO and axial orbits. Numerical simulations for 4000 virtual NEOs indicate that due to a better observation geometry, the detection system of axial orbits can find more NEOs than those of the DRO and EDHOs.