A SpaceX capsule carrying four astronauts has returned to Earth earlier than planned, splashing down safely in the Pacific Ocean off California. NASA says the mission was cut short due to a serious medical concern affecting one crew member. This marks the first medical evacuation in the history of the International Space Station — so what exactly happened in space?

<p>A SpaceX capsule carrying four astronauts has returned to Earth earlier than planned, splashing down safely in the Pacific Ocean off California. NASA says the mission was cut short due to a serious medical concern affecting one crew member. This marks the first medical evacuation in the history of the International Space Station &mdash; so what exactly happened in space?</p>

Welcome to the Daily News Dose Podcast by Onmanorama. Tune in to get updated about the major news stories of the day.

<p>Welcome to the Daily News Dose Podcast by Onmanorama. Tune in to get updated about the major news stories of the day.</p>

Daily News Dose

Welcome to the Daily News Dose Podcast by Onmanorama. Tune in to get updated about the major news stories of the day.04:09 PM