Optimal Solutions to Deflect Earth Crossing Objects Using Laser
Abstract
This paper solves and analyzes a trajectory optimization problem to deflect Earth-crossing objects (ECOs) employing continuous thrust obtained using a laser ablative system. The optimal control is determined for various initial ECO-Earth configurations to achieve the desired miss distance. The formulation incorporates the gravitational effect on the object due to the Earth using the patched-conic method. The constrained trajectory optimization problem is solved using Non-Linear Programming (NLP). First, the continuous control problem is solved, assuming both constant and variable power consumption, followed by a detailed comparison between the continuous control schemes. Subsequently, the work extends to studying sub-optimal solutions that can accommodate power fluctuations in the controller. The optimal control offers a range of alternative operational methods for asteroid deflection missions with trade-offs in power consumption and the total mission time. For impulsive deflection, the existing work reports two optimal solutions. One of the solutions is found to be better as it leads to a final ECO orbit that has its next Earth passage later than the other solution. Finally, the Moon's gravitational effect on the orbit of an ECO is studied. The reported results provide a comprehensive understanding of various scenarios in the process of ECO deflection.