NASA Launched Voyager 2 in 1977, Sending 1 Probe to 4 Outer Planets
Updated
Updated · Space.com · Aug 20
NASA Launched Voyager 2 in 1977, Sending 1 Probe to 4 Outer Planets
3 articles · Updated · Space.com · Aug 20
Summary
Aug. 20, 1977 marked NASA’s launch of Voyager 2, the first Voyager mission, on a rare-geometry route to Jupiter, Saturn, Uranus and Neptune.
That alignment let one spacecraft complete a 12-year planetary tour that remains unmatched: Voyager 2 is still the only probe to visit all four gas giants and the only one to fly past Uranus and Neptune.
Triton delivered one of the mission’s biggest surprises, with Voyager 2 images showing nitrogen plumes blasting miles above Neptune’s largest moon.
2018 brought a second milestone when Voyager 2 entered interstellar space; nearing 50 years of operation, it still returns data from three working science instruments.
About 4 watts of power are lost each year from its plutonium supply, pushing NASA to shut off non-science hardware and use a less demanding heating method to extend the mission.
With no successor missions planned, will our interstellar data stream permanently vanish once Voyager 2's final instrument shuts down?
Could the laser communication tech replacing Voyager's legacy radio systems ever catch up to the 50-year head start of our farthest probe?
As Voyager 2's nuclear battery inevitably dies, what will humanity's most distant ambassador encounter in the silent dark?
Voyager 2’s 50-Year Journey: Surviving, Discovering, and Communicating from Interstellar Space
Overview
Voyager 2, now over 13 billion miles from Earth, faces extreme challenges as its plutonium power source decays, losing about 4 watts each year. By 2026, this left the spacecraft with dangerously low power, threatening to shut down a science instrument. NASA engineers responded with the 'Big Bang' maneuver, swapping devices for lower-power alternatives and reducing demand by nearly 10 watts, allowing all three science instruments to keep running into 2027. This delicate balance is made harder because engineers must manage the spacecraft’s temperature without direct sensors, relying on models to prevent the fuel lines from freezing and ending the mission.