Voyager 1 survives clogged thrusters billions of miles away

Forty-Seven Years of Exploration

Launched in 1977, Voyager 1 has defied expectations by continuing its exploration mission for decades longer than anticipated. Its remarkable longevity has presented challenges as its components age in the harsh environment beyond our solar system. However, engineers at NASA’s Jet Propulsion Laboratory have proven their ingenuity in addressing these issues.

Beyond the Heliosphere

Currently, Voyager 1 is approximately 15 billion miles from Earth, operating beyond the heliosphere, a protective bubble of magnetic fields and particles emitted by the Sun. In this uncharted region, Voyager’s instruments directly sample interstellar space.

Clogged Thrusters, Compromised Communication

Earlier this year, engineers detected a critical issue with a fuel tube in one of Voyager’s thrusters, which threatened to disrupt communication with Earth. These thrusters maintain the spacecraft’s orientation, ensuring that its antenna remains pointed towards our planet.

Multiple Thruster Sets

Fortunately, Voyager 1 is equipped with three sets of thrusters: two sets of attitude propulsion thrusters and one set for trajectory correction maneuvers. In the past, the spacecraft has relied on all three sets, but as it now travels on a more stable path, only one set is required for communication stability.

Fuel Tube Clogging

Over time, a byproduct of the fuel tank’s rubber diaphragm has caused the fuel tube to become clogged. This accumulation of silicon dioxide reduces the thrusters’ force-generating capacity.

Historical Thruster Swaps

In 2002, engineers switched to the second set of attitude propulsion thrusters when the first set showed signs of clogging. In 2018, they utilized the trajectory correction thruster set as the second set also exhibited clogging.

Critical Clogging

However, recent inspections revealed that the trajectory correction thrusters were even more severely clogged than the previous sets. The tube opening had narrowed to just half the width of a human hair.

Back to the Beginning

Given the dire condition of the trajectory correction thrusters, the team decided to revert to the original attitude propulsion thruster set. However, the spacecraft’s cooling systems had been powered down to conserve energy, making it necessary to devise a workaround to prevent damage to the thrusters.

Warm-Up Strategy

Engineers realized they could temporarily disable one of the main heaters for an hour, providing enough power to activate the thruster heaters and safely complete the switch. This plan was successfully executed on August 27th.

Limited Thruster Lifespan

While the team has taken measures to extend the life of the original thruster set, its lifespan is limited. Once it becomes exhausted, Voyager 1’s only backup option is the other clogged set of attitude propulsion thrusters.

Weighing Future Decisions

As Voyager 1 continues to age, the mission team faces increasingly complex challenges. All future decisions must be carefully considered to ensure the spacecraft’s longevity and the preservation of its invaluable scientific data.

Voyager 2’s Journey

Voyager 2, Voyager 1’s twin probe, has also undergone thruster swaps but faces a less urgent situation. Having traveled over 12 billion miles from Earth, Voyager 2 provides valuable insights into the heliosphere and its protective role in shielding our planet from interstellar hazards.