We Just Sent A Signal 13 Billion Miles Into Space And Got A Response From A Decades-Old Spacecraft

VOYAGER 1 LAUNCHED IN 1977. NASA/JPL-CALTECH

NASA's Voyager 1 spacecraft, the farthest spacecraft from Earth, just turned on some of its thrusters that haven't been used since 1980.

Currently the only spacecraft we've ever sent to interstellar space, Voyager 1's attitude control thrusters – which it had used to point its antenna towards Earth – had been wearing down. When it can no longer point its antenna to Earth, we'll no longer be able to contact it.

In an effort to prolong the lifetime of the spacecraft, scientists at NASA's Jet Propulsion Laboratory (JPL) in California found they were able to use another set of thrusters on the spacecraft to perform this task. This could extend the life of the spacecraft beyond 2020.

"With these thrusters that are still functional after 37 years without use, we will be able to extend the life of the Voyager 1 spacecraft by two to three years," said Suzanne Dodd, project manager for Voyager at JPL, in a statement.

These thrusters are called the trajectory correction maneuver (TCM) thrusters. They were originally used by the spacecraft to navigate past the planets Jupiter and Saturn as it made its way out of the Solar System.

The latest planetary encounter was Saturn on November 8, 1980, so the thrusters hadn't been used since then. But the other day, the team decided to try firing them up again, to see if they still work.

They fired up the four thrusters for the first time in 27 years on Tuesday, November 28. It took 19 hours and 35 minutes for Voyager to send the results of the test back, owing to its distance from Earth (21 billion kilometers or 13 billion miles). On Wednesday, November 29, they got confirmation that it had worked. 

“The Voyager team got more excited each time with each milestone in the thruster test,” Todd Barber from JPL said in a statement. “The mood was one of relief, joy, and incredulity after witnessing these well-rested thrusters pick up the baton as if no time had passed at all."

The TCM thrusters are similar in size and functionality to the other thrusters. However, Voyager has to turn on one heater per thruster in order to use them, which drains power. So they'll use the TCM thrusters until there isn't enough power for the heaters and then switch back to the other thrusters.

All in all, it's good news for Voyager 1 fans. It means the spacecraft will last just that little bit longer, as it continues to send back fascinating data from beyond the Solar System. The team is planning to test the TCM thrusters on the twin Voyager 2 spacecraft, which should exit the Solar System in the next few years.