Butch Wilmore and Suni Williams were barely known outside space circles when they strapped in for what was supposed to be a quick test flight last June. Nine months later, they’ve captured the world’s attention and hearts as NASA’s stuck astronauts.

Their return caps a protracted space mission that was fraught with uncertainty and technical troubles and turned a rare instance of NASA's contingency planning - and the latest failures of Boeing's Starliner - into a global spectacle.

A four-member crew, including NASA astronauts Sunita "Suni" Williams and Barry "Butch" Wilmore, left the ISS early Tuesday on a SpaceX Dragon spacecraft.