NASA recently made the decision to deactivate one of Voyager 2’s five remaining instruments, signaling a potential nearing end to the historic mission of the space probes. In an announcement on October 1, the agency explained that the plasma science instrument on Voyager 2 was turned off to conserve the spacecraft’s remaining power supplies.
Voyager 1 and 2 are designed to explore deep space further than any other human-made object, but maintaining their functionality requires a sufficient power source. Both spacecraft use three radioisotope thermoelectric generators fueled by decaying plutonium-238. Over the years, the power supply has decreased due to the plutonium’s half-life, with the spacecraft currently operating on an estimated two-thirds of their original power.
The plasma science instrument on Voyager 2, designed to study the Sun’s particle emissions, consists of four cup-like tools. While it was crucial in determining Voyager 2’s exit from the heliosphere in 2018, its usefulness has diminished since then. The decision to power off this instrument was made after considering its decreasing utility.
Shutting down the plasma science instrument on Voyager 2 was a lengthy process, given the distance of the spacecraft from Earth. The signal to power off the instrument took 19 hours to reach Voyager 2, located over 12.9 billion miles away, and another 19 hours for the confirmation signal to return.
Despite the deactivation of certain instruments, both Voyager probes continue to push boundaries by venturing into deep space. With proper maintenance, Voyager 1 and 2 could potentially transmit data from at least one operating instrument into the 2030s. NASA’s engineers are diligently working to extend the lifespan of these iconic spacecraft.
