NASA’s Voyager probes have been coasting in interstellar space after leaving the solar system in the mid-2010s. A recent article in Scientific American said that the spacecraft would be shut down soon. That wasn’t wrong, but a little misleading. It has a few years of life yet.

NASA posted an update on the spacecraft’s Twitter recently saying that the spacecraft is still functioning and will still continue functioning up to the 2030s if possible. Five of the original eleven science instruments are still running, and NASA expects they can continue operating these instruments until 2027.

After that, Voyager will just phone home, sending and receiving data. Its transmitter only uses 23 watts of power, two and a half times less power than the average lightbulb. And that tiny amount of power sent us back thousands and thousands of amazing pictures and scientific data on Jupiter, Saturn, Uranus, and Neptune.

The Voyager spacecraft are extremely simple, with very little software to go wrong. The whole spacecraft has less memory than a key fob, according to Linda Spilker, a JPL scientist quoted in the Scientific American article. Microprocessors weren’t around when the spacecraft was being designed. Most of the vehicle functions are hardwired. The one resource driving how long Voyager can last is its power supply.

Voyager uses Radioisotope Thermoelectric Generators, RTGs, which take the heat produced by small pellets of plutonium-238 and convert that into a trickle of electricity. These were chosen because the spacecraft would be operating in the outer solar system and beyond, so solar panels would be insufficient. RTGs can provide power for decades, but Voyager has been in space for 45 years. So the mission will be coming to an end in a few years… just not right now.

More Information

Record-Breaking Voyager Spacecraft Begin to Power Down (Scientific American)