Rocket propulsion technology has progressed leaps and bounds since the first weaponized rockets of the Chinese and Mongolian empires. They were nothing more than rocket-powered arrows and spears but they set the foundations for our exploration of space. Liquid propellant, ion engines and solar sails have all hit the headlines as we strive for more efficient methods of travel but a team has taken the next leap with a palm-sized thruster system that could boost future tiny spacecraft across the gulf of space.