For observers watching from the ground, the visual distinction between a suborbital rocket launch and an orbital mission seems almost negligible. Both rely on immense, roaring propulsion systems, both push far past the thickest layers of the atmosphere...

For most of human history, space belonged to astronomers, scientists, national governments, and the unfettered imagination. Then, almost imperceptibly, a tectonic shift occurred. Private enterprises began engineering vehicles capable of carrying non-career astronauts beyond Earth’s atmosphere...