Voyager 1 will reach one light day (the distance light travels in 24 hours) from the sun in November 2026 after nearly 50 years in space. This milestone matters because it represents an extraordinary distance—about 17 billion miles—and demonstrates the probe's remarkable longevity despite running on extremely limited power. NASA just shut down one of its last remaining science instruments on April 17 to preserve power, leaving only two operational instruments on the spacecraft.