The two Voyager spacecraft may not have a long operational time left, according to scientists at NASA. Now, they say, the duo could have about five years before they lose connection back to earth, though the 42-year old probes will continue travelling indefinitely. Ed Stone, Voyager’s mission physicist and scientist at Caltech, said that the spacecraft is cooling down and the craft’s power supply is dropping. Speaking on October 31 in collaboration with publishing new scientific reports, he said that NASA might no longer have enough power to run scientific equipment on the probe.

The Voyager has far surpassed NASA’s expectations, lasting for more than half of the agency’s existence. Stone added that when the Voyager was launched, they did not expect them to last that long, and are even more surprised that the instruments on the probes, designed to last just four years, are still operational: four on the Voyager 1 and 5 on the Voyager 2. The devices were expected to turn a motor 250,000 times (called ‘steps’) to take measurements, explained Stamatios Krimigis, principal investigator of the Voyager’s low-energy particles investigation and space scientist at Johns Hopkins University Applied Physics Laboratory. The Voyager has taken close to 8 million steps according to recent data.

The Voyagers were launched a fortnight apart in 1977, with Voyager 1 scouting Saturn’s moon Titan before travelling outside our solar system in 2012 while Voyager 2 went around Uranus and Neptune before leaving the solar system as well in 2018, taking two hours to fly out of the bubble. Both are travelling at more than 48,000 kilometers an hour though due to the vast distance to earth, messages from the craft take 17-20 hours travelling at light speed.

Krimigis and Stone were speaking at an event to mark the release of the first in a series of scientific papers contrasting the two crossings outside our solar system. The two transitions to interstellar space are likely to be the only ones witnessed for a long time, considering that the New Horizons orbiting Pluto is expected to go silent before making the trip and a craft would take many years to reach the zone at current propulsion speeds. The two scientists said that the data from the two crossings are inconclusive to accurately describe the bubble around our solar system although they were happy that the spacecraft made it through, completely changing the perspective on the bubble and interstellar space as well.

This post was originally published on The Picayune Current