NASA Successfully Activates Thrusters on Voyager 1, Which is 24.63 Billion Kilometers from Earth.
Voyager 1, the farthest human-made object traveling through interstellar space, encountered a thruster issue that made it difficult for the spacecraft to orient itself toward Earth during communication. Unless Voyager 1 can switch to a different cluster of thrusters, the 47-year-old spacecraft will journey alone without support from Earth. The situation is further complicated by the fact that Voyager 1 is so old that sudden changes could potentially damage the spacecraft, Space reported on September 11.
Simulation of Voyager 1 pointing toward Earth. (Photo: NASA).
“Every decision we need to make to move the spacecraft forward requires more analysis and caution than before,” said Suzanne Dodd, project manager for the Voyager mission at NASA’s Jet Propulsion Laboratory.
The data collected by Voyager 1 plays a crucial role in space science, revealing more about the interstellar medium beyond the influence of solar gravity or particles. However, the spacecraft’s aging nuclear power source has significantly diminished, leaving very little electrical power. As a result, engineers at JPL have initiated a rescue plan to support the spacecraft’s maneuverability without jeopardizing the remaining operational scientific instruments on board.
Voyager 1 and its twin spacecraft, Voyager 2, were launched in 1977 to study the solar system. The duo flew past the four largest planets at the outer edge of the solar system in 1989 and continued to send scientific data after leaving the solar system in the early 2010s. Age has led to many changes in the Voyager spacecraft. The fuel lines for the thrusters have been prone to clogging for over 20 years. This issue arose as the rubber diaphragm in each spacecraft’s fuel tank deteriorated, producing silicon dioxide byproducts that clogged the lines.
Each Voyager spacecraft has three thruster branches available for use. Two branches are designed for orientation adjustments, while one branch is used for trajectory adjustments in space. Engineers have addressed unexpected issues for decades by repurposing some components of the Voyager spacecraft. However, the current situation with the thrusters presents an increased challenge.
On Voyager 1, the fuel line in the first orientation thruster branch began to clog in 2002, prompting a switch to the second branch. When the second branch became operational in 2018, all navigation functions of Voyager 1 shifted to the trajectory adjustment branch. However, during its usage, this branch also became severely clogged, even worse than the orientation thruster branch.
As a result, JPL decided to switch back to the orientation thruster system, but they had to do so with less power than in 2002. Voyager 1 is only operating essential systems, with some heaters even turned off. In the absence of heating and with minimal radiated heat from the few systems still operational on the spacecraft, the long-dormant orientation thruster branch had cooled to a point where turning it on could cause damage.
After thoroughly examining Voyager 1 remotely, the engineering team at JPL decided to resolve the issue by activating a heater for one hour. The command was effective, and on August 27, one of the orientation thruster branches successfully helped Voyager 1 point toward Earth for the first time in six years. In June, engineers also resolved a data transmission issue that had impacted the spacecraft for several months. The JPL team plans to keep the Voyager duo operational at least until the 50th anniversary of the mission in 2027.
