Both Voyager 1 and its twin, Voyager 2, have been bopping along for nearly a half-century, far beyond their original life expectancy. Launched in 1977, the pair was originally intended to study Jupiter and Saturn, their moons, and Saturn's rings.

Nasa scientists are celebrating as, after a period of silence, the craft recently called home again using a bit of kit that it hasn't used for more than forty years.

The 47-year-old NASA Voyager 1 fell back on a radio transmitter it hadn’t used since 1981 to ping home base after a technical issue caused a days-long communication stall between Earth and the farthest-ever recorded spacecraft.