Ever want to play a game of cosmic billiards? That's commonly how the DART mission was described when it successfully changed the orbit of a near-Earth asteroid last year. If you want an idea of how it works, just Google it and an Easter egg from the search giant will give you a general idea. But DART was more like trying to brute force a billiards break—there are many other things you can do with a set of asteroids and impactors on the galactic stage. One of the more interesting is to try to force two asteroids together to form a "contact binary"—the goal of a mission design put forward by a group of scientists from Cornell in a recent paper in Acta Astronautica.

Colby Merill and his colleagues at Cornell's Mechanical and Aerospace Engineering department first explain why such a mission would be a good idea.