It launched 35 years ago today, but the most distant spacecraft from Earth is stubbornly refusing to leave home turf. NASA's Voyager 1 has seemed on the verge of exiting our solar system for years, but new results suggest that it still has a way to go before it enters interstellar space. The latest readings from one of the spacecraft's instruments show that charged particles around Voyager 1 aren't changing direction the way they should at the heliopause, the boundary between the sun's sphere of influence and the rest of the galaxy. This could be a sign that the craft won't leave the solar system for up to 15 years, by which time it is expected to have run out of the power needed to communicate with Earth. The solar system sits in a huge magnetic bubble. Solar wind containing charged particles flows outwards from the sun, only to get bent around by the magnetic field, at the heliopause.