On December 6, Japan's Hayabusa2 probe successfully returned a capsule to Earth after a six-year voyage through space. It is believed to contain sub-surface materials collected on Ryugu, an asteroid some 300-million kilometers away. They may shed light on the origins of life on Earth. The mission faced a series of unexpected challenges and NHK went behind the scenes to see how the team achieved the extraordinary feat of two touchdowns on Ryugu and the safe return of the sample container.