Speaker
Description
Asteroids are of significant scientific and practical interest, as they represent primordial remnants from the early Solar System. Often referred to as the "building blocks" of planets, these celestial bodies offer unique insights into the processes that governed planetary formation and the evolution of other celestial objects. Additionally, understanding asteroid compositions and orbital dynamics is critical for planetary defense and resource exploration, as many asteroids contain valuable minerals and materials. A promising approach to asteroid exploration involves transferring an asteroid to an Earth satellite orbit using a spacecraft. Capturing an asteroid into a Moon-resonant orbit creates periodic low-energy launch windows, enabling cost-effective spacecraft deployment for prolonged, detailed study. For crewed missions, this trajectory also provides rapid return capabilities in emergencies or during short-duration missions. Furthermore, this method has potential applications for planetary defense, as it allows for altering the trajectory of an asteroid on a potential collision course with Earth, reducing the risk of hazardous impacts.
This paper presents a mission scenario designed to transfer an asteroid with suitable orbital and mass characteristics into a stable Earth satellite orbit. The proposed strategy begins with applying an optimal velocity impulse to modify the asteroid's trajectory for a gravity assist maneuver near Earth. This maneuver places the asteroid into a heliocentric orbit resonant with Earth's orbital period. Key mission parameters are computed to ensure that during each subsequent Earth-Moon encounter, the asteroid's velocity relative to Earth decreases, while its heliocentric velocity remains synchronized with Earth's orbital motion. This synchronization minimizes any velocity increase relative to Earth, ultimately reducing the asteroid’s velocity below Earth's parabolic escape threshold. The mission design involves multiple lunar flybys, which progressively lower the asteroid's velocity and culminate in its capture into a stable Earth satellite orbit. Detailed calculations are presented, including the required initial velocity impulse to redirect the asteroid, the trajectory parameters ensuring resonance between the asteroid and Earth's heliocentric orbit, the sequence of gravity assist maneuvers and their cumulative impact on reducing the asteroid's Earth-relative velocity and the capture conditions and orbital stability following lunar flybys. Additionally, simulation results are presented to demonstrate the feasibility of this method for a sample asteroid with predefined mass and orbital parameters. These results confirm that the asteroid can be safely captured with minimal fuel consumption while maintaining precise trajectory control.
This approach not only advances asteroid science by enabling long-term, close-proximity study but also enhances planetary defense strategies. By redirecting potentially hazardous asteroids away from Earth-crossing orbits, this technique provides a dual benefit: mitigating impact risks and enabling resource utilization.