NASA and SpaceX are preparing to carry out the first medical evacuation of astronauts from the International Space Station, a mission that will test how well two decades of planning translate into action when a crew member’s health is on the line.

SpaceX early Sunday morning launched its first Twilight rideshare flight from California, launching satellites for NASA, an Internet-of-Things services company and an experiment to 3-D print a boom in space.

Leroy Chiao, a retired NASA astronaut and ISS commander, joins "CBS News 24/7" to discuss NASA astronauts returning early due to a medical concern for a crew member at the International Space Station.