Voyager 2's demise has been postponed after NASA
found a way to hack a backup source of power to keep the probe going until
2026.
Voyager 1 and 2 have provided crucial scientific
information in their 45 years of spaceflight.
Today, the probes are traveling in interstellar
space, 12 and 14 billion miles away from Earth. That's further than any
spacecraft or human-made object has gone before.
"The science data that the Voyagers are
returning gets more valuable the farther away from the sun they go," said
Linda Spilker, Voyager's project scientist at NASA's Jet Propulsion Laboratory
in Southern California.
"We are definitely interested in keeping as
many science instruments operating as long as possible."
The probes have been traveling for 45 years
Voyager 1 and 2 set off a month apart in 1977. The
probes were initially meant to set off on a four-year mission to sail past
Saturn and Jupiter.
They were launched with a "golden record"
with information that would provide aliens with information about the Earth.
But the probes kept exceeding expectations, and NASA
has continually extended their missions, first to visit Neptune and Uranus,
then to sail further than any other probe: past the heliosphere.
The heliosphere is a bubble of particles and
magnetic fields that extend from the sun. This sphere is particularly important
for Earth because it protects us from galactic cosmic radiation.
Because the probes are now outside of this
heliosphere, their measurements provide unprecedented insights into the
bubble's properties, like its shape and its protective role.
NASA hacked the ancient probe's power system
The probes are powered by generators that convert
heat from decaying plutonium into electricity. As this energy source becomes
weaker, NASA engineers have had to shut down non-essential instruments, like
the probes' cameras and heaters, to conserve power.
But as Voyager 2 was entering its last energy
reserves, NASA engineers came up with a clever hack that would allow it to stay
alive a little longer.
They found a way to divert power from a safety
mechanism designed to turn on if the probes' circuit malfunctions because of
voltage variations.
"Variable voltages pose a risk to the
instruments, but we've determined that it's a small risk, and the alternative
offers a big reward of being able to keep the science instruments turned on
longer," said Suzanne Dodd, Voyager's project manager at JPL, in a press
release.
"We've been monitoring the spacecraft for a few
weeks, and it seems like this new approach is working."
NASA may consider using it on Voyager 1. One of
Voyager 1's instruments previously malfunctioned, which means the probe has not
been using up as much power as Voyager 2.
The decision to switch off instruments for Voyager 1
will be made next year, according to the space agency.