Propulsion systems and methods utilize one or more propellant masses in the form of smart propellant devices to move a spacecraft or other object through outer space and/or substantially airless environments. A spacecraft maneuver, for example, is facilitated by forces imparted on the spacecraft resulting from the ejection of one or more smart propellant devices from the spacecraft and/or the recapture of one or more of the propellant masses at the spacecraft. The smart propellant devices are each programmed to return to the spacecraft along a particular trajectory and to impact the spacecraft at a particular time and place. The spacecraft is provided with ejection devices and recovery devices that eject and recover, respectively, the one or more smart propellant devices. The recovery devices can also be configured to capture kinetic energy from incoming smart propellant devices.