Voyager 1, launched in September 1977, crossed over into interstellar space in 2012. (Image credit: NASA) The pioneering Voyager probes might only have a few years left to explore interstellar space, and that's assuming a planned, risky maneuver in 2026 goes well. NASA's twin Voyager 1 and Voyager 2 spacecraft, both running on nuclear power, now have access to just a portion of the 470 watts of energy that they generated immediately after their 1977 launches. Originally tasked with exploring the giant planets in our solar system, the pair have long passed their expected lifespans and are still transmitting data, far from home. What's running? What's not? Both Voyager probes launched with the same 10 operational instruments. Voyager 1 turned off its subsystem to look at cosmic rays (high-energy particles) in February, then did the same with its Low-Energy Charged Particles (LECP) instrument in April .…