These are the goals of the Breakthrough Propulsion Physics program:
(1) Eliminate or dramatically reduce the need for rocket propellant. This implies discovering fundamentally new ways to create motion, presumably by manipulating inertia, gravity, or by any other interactions between matter, fields, and spacetime.

(2) Dramatically reduce trip time to make deep space travel practical. This implies discovering a means to move a vehicle at or near the actual maximum speed limit for motion through space or through the motion of spacetime itself. If possible, this means circumventing the light speed limit.

(3) Discover fundamentally new on-board energy production methods to power propulsion devices. This third goal is included in the program since the first two breakthroughs could require breakthroughs in energy generation to power them, and since the physics underlying the propulsion goals is closely linked to energy physics.