Voyager probes powered by 1960s nuclear battery technology

NASA's Voyager probes, launched nearly 50 years ago, continue to operate thanks to nuclear batteries called radioisotope thermoelectric generators (RTGs). These RTGs were invented in the 1960s and are crucial for powering missions far from the Sun, where solar panels are ineffective. Solar energy works well for spacecraft near Earth, but as they travel deeper into space, sunlight weakens. This means alternative power sources are necessary for long missions. RTGs use the radioactive decay of plutonium-238 to generate heat and then electricity, allowing the probes to function in the extreme environment of space. RTGs generate power without moving parts, making them reliable and durable. They produce a constant output as plutonium-238 decays over decades. This consistent energy has supported several NASA missions, including Mars rovers and the New Horizons spacecraft. Voyager 1 and Voyager 2 are the most famous missions using RTGs. They were launched in 1977 and have traveled billions of miles from Earth. Even after almost half a century, both probes remain active, sending valuable scientific data back home, showcasing the effectiveness of the technology.