If there are multiple asteroids that meet these constraints, a particular object could be selected based on the type of asteroid and science potential. However if there are no asteroids that meet these constraints, one would want to know what is the largest asteroid that can be visited under the same mission constraints. Alternatively, how much additional ΔV is required to reach the desired 1 km-sized asteroid? What are the backup opportunities if there is a launch slip? Another class of mission design questions relate to trajectories for round-trip transfers to Near-Earth Objects (NEOs) for human missions in the next decade.