NASA has shut down one of Voyager 1's science instruments to conserve power and keep the nearly 49-year-old spacecraft operating. The move comes as Voyager 1, which is now over 15 billion miles from Earth, loses about 4 watts of power each year. The Jet Propulsion Laboratory (JPL) in Southern California has sent commands to turn off Voyager 1’s Low-Energy Charged Particles (LECP) experiment, a long-running instrument since the spacecraft launched in 1977. The remaining LECP instrument will remain powered because it uses only about half a watt. The decision to shut off LECPs underscores the delicate balancing act facing the Voyager team as both spacecraft age beyond their original mission plans.