NASA has shut down one of the last remaining science instruments of the Voyager 1 spacecraft, the Low-Energy Charged Particle (LECP) experiment, in an attempt to preserve power. The decision comes ahead of a potentially risky 'Big Bang' maneuver that mission managers hope will boost the two probes' lives later this summer. Voyager 1, which launched in 1977, is running low on nuclear power after a planned roll maneuver on Feb. 27 created an unexpected power drop. Only two of Voyager 1's 10 science instruments remain powered, while three instruments are currently running on Voyager 2. The plan involves replacing several powered devices with lower-power alternatives to keep the spacecraft warm enough to continue gathering science data.