Voyager 1 keeps hanging on

 

Voyager 1 is way, way, way, way, way out in space. And it's old. And it's cold. And it's radioactive isotope heaters are running out of radioactivity. And it's running with a computer that requires weeks to reprogram.

Yet still it persists.  And what's more, when they ask something on it to work, it still does.

NASA built this one right.

47-year-old Voyager 1 spacecraft just fired up thrusters it hasn’t used in decades

The basic story is that the elderly spacecraft has three sets of thrusters, and only needs one to keep it aligned and communicating with Earth. But as the thrusters are used, they get clogged (somewhat like arteries). One set got so clogged that they decided they had to switch to a different set of thrusters. But that required some extra effort, as described here:

"As Voyager 1 and its twin probe, Voyager 2, have aged, the mission team has slowly turned off nonessential systems on both spacecraft to conserve power, including heaters. As a result, components on Voyager 1 are colder now, and the team knew it couldn’t just send a command to Voyager 1 to switch immediately to one of the attitude propulsion thrusters without doing something to warm them up.

But Voyager 1 doesn’t have enough power to switch any heaters back on without turning something else off, and its scientific instruments are too valuable to shut off in case they don’t come back on, the team said.

After going back to the drawing board, the team realized it could shut off one of the spacecraft’s main heaters for about an hour, which would enable engineers to turn on the thruster heaters and safely make the switch.

This plan worked, and by August 27, Voyager 1 was back to relying on one of its original thruster sets to stay in touch with Earth."

At this time, Voyager 1 is 15 billion miles from Earth, and Voyager 2 is 12 billion miles away. 

Keep in touch a couple more years, V1.