NASA/JPL-Caltech
Currently, the Voyager 1 spacecraft is 13 billion miles from Earth, or about 141 times the distance between Earth and the Sun. It has, in fact, moved beyond our solar system into interstellar space. However, we can still communicate with Voyager over that distance.
This week, the scientists and engineers of the Voyager team did something very special. They ordered the spacecraft to fire a set of four orbiting thrusters for the first time in 37 years to determine if they could orient the spacecraft using 10-millisecond pulses.
After sending the commands on Tuesday, it took 19 hours and 35 minutes for the signal to reach Voyager. Then the Earth-bound spacecraft had to wait another 19 hours and 35 minutes to see if the spacecraft responded. It did. After nearly four decades of rest, the thrusters manufactured by Aerojet Rocketdyne fired perfectly.
“The Voyager team grew more and more excited with each thruster test milestone. The mood was one of relief, joy and disbelief as they watched these well-equipped thrusters take over as if no time had passed at all,” he said . Todd Barber, propulsion engineer at the Jet Propulsion Laboratory in California.
In recent decades, Voyager has relied on its primary thrusters to keep the spacecraft properly oriented so it can maintain a communication link with Earth. But these attitude control thrusters have degraded over time, requiring more and more energy each time they have been used.
By switching to the spacecraft’s “orbit correction maneuver” thrusters, which were last used during the spacecraft’s 1980 encounter with Saturn, engineers say they could extend Voyager’s life by two or three years before the dwindling power reserves run out.