This has really been a wonderful journey that began with the launch of two spacecraft in 1977 to explore Jupiter and Saturn, our journey has expanded deeper and deeper into space. We had no quantitative idea of how big this bubble is that the sun creates around itself with its supersonic solar wind, made of ionized plasma, which is speeding away from the sun in all directions. And we didn't know the spacecraft could live long enough to reach the edge of the bubble, leave it and enter nearby interstellar space.