The Voyager mission to the outer planets was arguably one of the greatest voyages of discovery in the history of human exploration. Over the course of a dozen years, NASA’s twin Voyager probes explored every outer planet, save for Pluto, to take advantage of a rare planetary alignment that will not reoccur until the mid-22nd century. In celebration of the historic 25th anniversary of the Voyager 2 encounter at Neptune, the latest installment in my continuing series on the history of the Voyager mission to the outer planets, ”The Grand Tour Finale: Neptune”, has been published on line in The Space Review. The background of the mission of Voyager 1 to Saturn’s moon, Titan, is covered in “Voyager 1: The First Close Encounter with Titan” while details of the Voyager 2 encounter with Uranus in 1986 (a recommended prequel to the new article) are given in “Voyager 2: The First Uranus Flyby” .
This new article covers the history of the mission of Voyager 2 to Neptune from its origins almost half a century ago as part of NASA’s proposed “Grand Tour of the Outer Planets” until the encounter a dozen years after launch – the longest planetary mission until that point in history. Given how little was actually known about Neptune and its pair of then-known moons, Nereid and Triton, due to their great distance from the Earth, the Voyager 2 encounter with Neptune was one guaranteed to make many new discoveries. Not even the upcoming encounter of New Horizons with Pluto, which will finally complete NASA’s original “Grand Tour”, will be able to reproduce the magnitude of discovery of the Neptune encounter with Voyager 2. Indeed, it could be argued that the achievements of the Voyager mission will not be reproduced until the first exploration of an extrasolar planetary system maybe centuries from now.
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Related Video
This is a JPL-produced documentary from 1990 on the Voyager mission to the outer planets.
Related Reading
“The Grand Finale: Neptune”, The Space Review, Article #2586, August 25, 2014 [Article]
“Voyager 2: The First Uranus Flyby”, Drew Ex Machina, January 24, 2016 [Post]
“Voyager 1: The First Close Encounter with Titan”, Drew Ex Machina, November 12, 2015 [Post]
“The Next Mission to Pluto”, Drew Ex Machina, July 14, 2014 [Post]
When Carl Sagan wrote the Voyager planetary mission section of the 1978 book Murmurs of Earth about the Voyager Interstellar Record, he mentioned that Voyager 2 might go on to Uranus as an option but said nothing about Neptune. So NASA/JPL definitely played that hand close to their chest even around launch time.
Sagan also said in the same chapter that Io might have dry seas of salt but said nothing about possible volcanoes. :^)