Radio. Voyager is nuclear powered (Thought not in the sense you're probably thinking. It's a nuclear source and a thermoelectric cell.), and many (most?) of the

Radio. Voyager is nuclear powered (Thought not in the sense you're probably thinking. It's a nuclear source and a thermoelectric cell.), and many (most?) of the instruments are still functioning and sending signals back. It really is quite astounding when you think about it! Launched in 1977, traveled through the solar system, and still functioning!