• Mr. Geoff Patterson
  • University of Hawaii
  • Holden Auditorium (Room 112)
  • 4:00 p.m.
  • Faculty Host: Dr. Craig Woolsey

Temporarily-captured Natural Earth Satellites (NES) are near Earth asteroids that get temporarily caught in orbit around Earth. These objects intuitively make appealing targets for space missions because they are very close to home. In order to determine just how appealing they are, fuel-minimal asteroid rendezvous missions are investigated using a catalogue of over sixteen-thousand simulated NES. The spacecraft is assumed to start at the Earth-Moon L2 Lagrangian point, with specifications comparable to a chemical propulsion system. The Circular Restricted Four Body Problem is used to model the gravitational effects of the Earth, Moon, and Sun. Indirect methods of optimal control based on the Pontryagin Maximum Principle are employed to identify fuel-optimal transfers, and a foliation technique is used to overcome the well-known difficulty of initializing such algorithms. Our methods produce rendezvous missions for a significant percentage of the simulated asteroids, with delta-v values as low as 44 meters per second. 


Mr. Patterson is completing his doctorate in mathematics at the University of Hawaii at Manoa under the mentorship of Dr. Monique Chyba.