If the dreams of space agencies and private companies come to fruition, within a couple of decades we’ll have orbiting hotels and lunar mining colonies, and the first human visitors will be en route to the Red Planet. But astrophysicist Erika Nesvold argues that the shape of tomorrow’s space expeditions and conflicts could depend on ethical choices people make today. Nesvold is coeditor of the book Reclaiming Space, which was published today, and the author of Off-Earth, due out on March 7. She’s also a cofounder of JustSpace Alliance, a nonprofit organization that advocates for a more inclusive and ethical future in space, and a developer for Universe Sandbox, a physics-based space simulator.