NASA has made contact with the "lost" Pioneer 10 probe, which was launched in March 1972 on the first mission to Jupiter. Pioneer 10 - the first spacecraft to leave the solar system - is currently 11.7 billion km (7.26 billion miles) away from Earth travelling at 35,800 km/h. Signals take 21h 45min to make the round trip to Earth and back.
Source: Flight International