Somewhere over the Atlantic on a clear Florida evening, a Falcon 9 rocket lifted four people off the planet. Two were NASA astronauts, one was a Russian cosmonaut, and one was a Canadian astronaut whose wife, back on Earth, is expecting their third child. By the time the baby arrives, roughly two months from now, its father will still be circling the planet every 90 minutes, watching continents slide past the window of the International Space Station. It sounds like the plot of a science fiction film, but it has happened only three times before in the entire history of human spaceflight.

If all goes as planned, this will be the fourth. Pregnancy and childbirth are complicated enough without one parent being, quite literally, out of this world. Yet space agencies have learned to treat such moments almost matter-of-factly now, scheduling video calls and medical check-ins around orbital mechanics as easily as they once scheduled them around time zones. Getting off the ground was not simple this time.

The launch had originally been planned for mid-September, but engineers delayed it after discovering a faulty valve in the Crew Dragon capsule's propulsion system. Nobody wanted to take chances with a vessel meant to carry humans. Once the valve was replaced and tested, the mission finally proceeded, with the crew expected to dock at the station after a seven-hour, fifty-minute journey. Once aboard, the astronauts will spend months running experiments designed to prepare humanity for journeys to the Moon and, eventually, Mars.