Graphic depiction of Swarming Proxima Centauri: Coherent Picospacecraft Swarms Over Interstellar Distances Thomas Eubanks Tiny gram-scale interstellar probes pushed by laser light are likely to be the only technology capable of reaching another star this century. We presuppose availability by mid-century of a laser beamer powerful enough (~100-GW) to boost a few grams to relativistic speed, lasersails robust enough to survive launch, and terrestrial light buckets (~1-sq.km) big enough to catch o...