NASA shuts off another Voyager 1 instrument as humanity’s most distant spacecraft prepares for risky ‘Big Bang’ maneuver to save power
After nearly half a century in space, the Voyager 1 spacecraft has just turned off one of its last scientific instruments in a desperate attempt to conserve energy. NASA’s decision to turn off the instrument comes just before a final “Big Bang” moment that mission managers hope will give the two Voyager probes an extra boost of life later this summer.
On Friday, April 17, Voyager 1 was ordered to shut down the Low-Energy Charged Particle (LECP) experiment, an instrument that has studied ions, electrons and cosmic rays surrounding the spacecraft for the past 49 years.
The spacecraft was launched in 1977, initially to study Jupiter and Saturn, before its mission was extended numerous times. In 2012, Voyager 1 officially entered interstellar space, becoming the first spacecraft to send data from outside the solar system. It remains the most distant spacecraft in history.
The twin Voyager 2 probe, which studied all the outer planets from Jupiter to Neptune, entered interstellar space about six years later, and the two spacecraft are still transmitting from the dark.
But their time is running out. Both spacecraft rely on a radioisotope thermoelectric generator, which converts decaying plutonium into energy. The spacecraft loses about 4 watts of power per year.
“Power margins became razor thin, forcing the team to conserve energy by turning off heaters and instruments while ensuring that the spacecraft did not cool to the point that its fuel lines froze,” wrote representatives of NASA’s Jet Propulsion Laboratory (JPL), which manages the Voyager program. in a blog post from April 17.
After the last stoponly two of Voyager 1’s ten science instruments remain powered, while three instruments currently operate on Voyager 2. These instruments have helped scientists characterize conditions in space beyond the solar system, as well as the physical properties of the heliopause, the boundary where the solar wind collides with the interstellar medium.
A “Big Bang”
This final shutdown of Voyager 1’s instruments will only give the spacecraft about a year of life, as things stand, but there is a plan to get the most out of the spacecraft: JPL will use a “Big Bang” procedure to try to expand the dwindling power reserves of not only Voyager 1 but also Voyager 2.
“The idea is to swap out a group of powered devices all at once — hence the nickname — by turning off certain elements and replacing them with lower-power alternatives, in order to keep the spacecraft warm enough to continue collecting science data,” JPL representatives wrote in the blog.
For now, two Voyager 1 instruments are examining magnetic fields and plasma (superheated gas) waves. But if all goes as planned, the team hopes to recover enough power from the Big Bang to reignite the LECP. In fact, engineers decided to leave a small half-watt motor running for the LECP for now, just in case the instrument might be used again.
In May and June, JPL will conduct Big Bang tests on Voyager 2, which has more power supplies and is slightly closer to Earth. Assuming all goes well, the Voyager 1 Big Bang’s riskiest moment wouldn’t occur until July.
Sending commands to Voyager 1 takes 23 hours because it is very far from Earth —15 billion miles away (25 billion kilometers). After JPL relayed its commands, the LECP shutdown process lasted just over three hours. Restarting, especially given the cold and the distance, could be a little trickier.
