Description: The tyranny of the rocket equation dictates that to increase velocity linearly, we need exponentially more fuel. This scaling applies to all propulsion mechanisms that carry onboard fuel with profound implications: for example, it took the Voyager probes over 30 years to reach the outskirts of our Solar System, and with current technology any mission to deep space would require decades. Directed energy laser-driven sails offer enormous opportunities to overcome this limitation, using the radiation force of light for acceleration. To advance the potential of directed energy propulsion, we propose to develop nanostructured photonic lightsails, where light-sail interactions are deliberately engineered from nano to macro scales to enable lightweight, stable, and high-thrust lightsails. This approach aims to advance the ultimate vision of directed energy propulsion for fast, frequent, and scalable space exploration missions within and beyond our Solar System.