After a lull, the Voyager 1 spacecraft is back in action. NASA’s landmark mission has resumed its regular operations after a month-long pause in communication.
In late October, Voyager 1 suddenly turned off one of its radio transmitters, forcing the mission team to rely on a backup device, a weaker transmitter that had not been used since 1981. Earlier this month, however, the mission team managed to turn on the spacecraft’s main radio transmitter, called the X-band transmitter, and resume collecting valuable data from Voyager’s four working science instruments, NASA said on Tuesday.
The mission, launched in 1977, was the first spacecraft to cross the boundary of the solar system and enter interstellar space. Now 15 billion miles (24 billion kilometers) from Earth, Voyager 1 is becoming increasingly difficult to maintain.
In early October, the mission crew realized that something was wrong with Voyager 1’s communications when the spacecraft did not respond to a command. It turned out that the fault protection system had turned off the X-band transmitter, which autonomously responds to onboard problems affecting the mission, after engineers activated one of Voyager’s heaters.
The fault protection system sensed that the probe was running low on power and, in turn, tried to shut down the non-essential system. Unfortunately, the interstellar probe had already shut down all of its nonessential systems during its mission, except for four scientific instruments. With no other choice, the fault protection system turned off the X-band transmitter and turned on the weaker S-band transmitter, which consumes less power.
Since communication with the spacecraft is critical, the mission team worked to turn the X-band transmitter back on and is currently performing several other tasks to return Voyager 1 to normal, such as rebooting the system that synchronizes its three onboard computers.
Both Voyager probes are running low on power after traveling through space for 47 years. Spacecraft are powered by heat from the decay of plutonium, which is converted into electricity. Every year, aging spacecraft lose about 4 watts of power. In an effort to conserve the spacecraft’s energy, the mission team has shut down all systems that are not necessary to keep the probes flying in space.
The team of engineers working on the mission had to come up with creative ways to keep Voyager 1 moving. Recently, the team switched to a different set of engines than the ones running the spacecraft, which had become clogged with silica over the years, using a delicate procedure to keep Voyager 1 powered. Earlier this year, the team of engineers also fixed a communications glitch that was causing Voyager 1 to transmit unintelligible messages to ground control.
“Voyager 1 is a spaceflight favorite that has been supplying scientists with precious data about the solar system and its surroundings for decades. On its way to interstellar space, the probe had close encounters with Jupiter and Saturn and discovered two of Jupiter’s moons, Phebe and Metis, as well as five new moons and a new ring called the G-ring around Saturn.
The harsh space environment has taken its toll on the older probe, and its distance from Earth makes it difficult to troubleshoot Voyager’s operations.
