Chemical rockets have taken us to the moon and back, but traveling to the stars demands something more powerful. Space X’s Starship can lift extraordinary masses to orbit and send payloads throughout the solar system using its chemical rockets, but it cannot fly to nearby stars at 30% of light speed and land. For missions beyond our local region of space, we need something fundamentally more energetic than chemical combustion, and physics offers, or, in other words, antimatter.