After nearly forty years of inactive wandering in space, the thrusters of NASA’s fastest and farthest unmanned spacecraft , Voyager 1, are reigniting.
This is the only man-made object in interstellar space and the one that has traveled the furthest, at a distance of approximately 21 billion km , leaving even our Solar System behind.
Since its launch on September 5, 1977 , Voyager 1’s mission has been to locate and study the limits of this planetary system. The spacecraft consists of four devices called “attitude control thrusters” that serve to automatically orient the probe and communicate with Earth . These thrusters work by firing tiny pulses, or “puffs,” lasting just a few thousandths of a second, gently turning the spacecraft and allowing its antenna to point continuously at our planet.
Over time, the Voyager team has observed that these devices have been degrading. And it is that the propellants increasingly need more puffs to emit the same amount of energy as in the past. For this reason, since 2014 this wear has been monitored and they began to consider how to solve the problem.
A group of propulsion experts, consisting of researchers Chris Jones, Robert Shotwell, Carl Guernsey and Todd Barber, analyzed the options and predicted how the spacecraft would respond in different scenarios. They agreed on an unexpected solution : the orientation job would be handed over to all 4 thrusters who had been asleep for 37 years.
On November 28, 2017 , NASA researchers sent a signal to the space probe to reactivate these propellants, inactive since 1980. It took 19 hours and 35 minutes of waiting for that message to reach the probe , and it was not until on the 29th when they were able to verify that the probe was responding correctly, indicating that the thrusters had been activated in 10 millisecond puffs.
“The Voyager flight team has extracted data from decades ago and examined the software, which was encoded in an outdated language, to ensure that we could safely test the thrusters,” says Jones.
Two or three more years of useful life
It is estimated that this action allows to extend the useful life of the probe between two and three years before its battery is completely depleted. At that point, your thermoelectric radioisotope generators will no longer be able to supply enough power.
The thruster test has been so successful that the team is likely to run a similar test on the thrusters of Voyager 2 , Voyager 1’s twin spacecraft. Fortunately, unlike the first, the attitude control thrusters of Voyager 2 is not that worn out yet. This latest probe is also on its way to enter interstellar space in the next few years.
