From Henry Blodget – Voyager Is Leaving The Solar System!:
The Voyager 1 space probe, which launched in 1977, has now reached the edge of the solar system Chris Wickham at Reuters reports. It will soon become the first and only man-made object to enter interstellar space.
Voyager is now about 18 billion kilometers from the sun. It's traveling at 17 kilometers per second. It takes 16 hours and 38 minutes for its radio signals to reach earth.
The probe is powered by plutonium, a power source that is designed to last until 2025. After that, Voyager will keep speeding through space, but we'll never hear from it again.
Voyager photo by San Diego Air & Space Museum Archives - http://flic.kr/p/bEhK6C