With a 2 billion mile journey ahead of it, the Juno explorer will be the most distant probe ever powered by the sun.
The craft, which is outfitted with three huge solar panels, is scheduled to lift off from the Kennedy Space Centre in the US state of Florida on Friday morning. It will be carried into space aboard an unmanned Atlas V rocket.
Southwest Research Institute astrophysicist Scott Bolton, Juno's principal investigator, said the mission, coming just two weeks after the final flight of the manned space shuttle, shows that NASA is not fading into oblivion.
"If we're going to learn who we are and where we came from, and how the Earth works, we've got to keep doing these science missions, not just Juno," Bolton told the Huffington Post.
NASA's long-range plans include landing astronauts on an asteroid by 2025 and on Mars a decade later; still unknown is what kid of craft will take them there.
A successful mission by Juno would help answer that question and lay the groundwork for future solar-powered missions of all types.
It will take Juno five years to reach its target, five times farther from the sun than Earth. No spacecraft has ever ventured so far, powered by solar wings.
The European Union’s solar-powered, comet-chasing Rosetta probe made it as far as the asteroid belt between the orbits of Mars and Jupiter.
Each of Juno's three wings is 29 feet long and 9 feet wide, necessary given that Jupiter receives 25 percent less sunlight than Earth. The panels – folded for launch – will spread out in space, and look like nothing so much as the blades of a windmill.
At Jupiter, nearly 500 million miles from the sun, Juno's panels will provide 400 watts of power. In orbit around Earth, these panels could generate 35 times as much power.
And Juno isn’t the only solar-powered flight NASA has in the cards this year. Next month’s Grail mission -- during which two spacecraft will be fly to the moon -- will also be solar powered.
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