Keeping Voyager alive: NASA’s project scientist faces painful choices as the iconic mission nears its end

NASA's Voyager mission faces difficult power-saving decisions as it nears its end.

: The Voyager spacecraft, launched in 1977, are nearing the end of their missions due to diminishing power from decaying plutonium. Linda Spilker, project scientist for the mission since its inception, details the emotional and technical challenges of managing the aging spacecraft. With only three instruments per spacecraft still operational, the team faces hard decisions as power cuts continue each year. Hopes remain to extend the mission to its 50th anniversary in 2027 with ongoing scientific contributions.

NASA's Voyager mission, consisting of two spacecraft launched in 1977, is nearing its inevitable conclusion as their power sources gradually weaken. The spacecrafts are powered by heat from decaying plutonium, converting it into electricity, losing around 4 watts of power each year. Linda Spilker, Voyager’s project scientist since the mission’s beginning, sheds light on the necessity to turn off non-essential systems and a few scientific instruments to conserve power. Each Voyager started with ten instruments but is now down to three, with more shutdowns potentially happening within the next year.

Spilker reflects on the evolution of the mission, noting the downsizing in team size from planetary days to the current interstellar mission. Initially, there was uncertainty about the heliopause's location, an area marking the boundary where the solar influence ends and interstellar space begins, which Voyage 1 entered in 2012 followed by Voyager 2 in 2018. Since then, these spacecraft have provided invaluable data on particles, cosmic ray abundance, and the magnetic field in interstellar space, exploring dimensions previously unknown.

Emotional connections to the spacecraft arise as the mission wind-down progresses; a sentiment akin to losing a close companion resonates within the Voyager team. On operating such an aged mission, Spilker highlights the challenge—technology from the 1970s with very limited computing memory presents risks of key pieces failing followed by necessity mandates to turn off redundant or backup units, thereby leaving critical components vulnerable.

Contingency measures and the dexterous act of maximizing remaining resources are underscored with anecdotes like a chip failure instance—which necessitated reprogramming efforts pulled from long-retired memos. Specialized knowledge passed on from prior engineers and scientists, aiding in troubleshooting by operating within outdated machine languages, exemplifies the collaborative resolve in optimizing the endurance of the spacefaring giants.

Looking onwards, there’s an aspiration to celebrate the Voyagers' golden anniversary come 2027, possibly extending to the early 2030s with minimal instrumentation functioning. The lasting impact of the mission amplifies hopes for launching new interstellar probes to explore more; an intriguing consequence lingering from unpredictably rich voyages made possible by decades-past technological marvels.

Sources: NASA, Gizmodo, Passant Rabie

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