CAPE CANAVERAL — NASA's upcoming mission to Jupiter can't get much greener than this: a solar-powered, windmill-shaped spacecraft.
The robotic explorer Juno is set to become the most distant probe ever powered by the sun.
Juno is equipped with three tractor-trailer-size solar panels for its 2 billion-mile journey into the outer solar system. It will be launched Friday morning aboard an unmanned Atlas V rocket — barely two weeks after NASA's final space shuttle flight.
The shuttle's demise is giving extra oomph to the $1.1 billion voyage to the largest and probably oldest planet in the solar system. It's the first of three high-profile astronomy missions coming up for NASA in the next four months.
Scientists hope to learn more about Jupiter's origins through Juno's exploration of the giant gas-filled planet, a body far different from rocky Earth and Mars.
"Look at it this way — it is a new era," said Jim Green, NASA's director of planetary science. "Humans plan to go beyond low-Earth orbit. When we do that, it's not like Star Trek. It's not 'go where no man has gone before.' "
NASA's long-range blueprint would have astronauts reach an asteroid by 2025. A Juno success would be a good sign 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. Europe's solar-powered, comet-chasing Rosetta probe made it as far as the asteroid belt between the orbits of Mars and Jupiter.
NASA's six-wheeled, Jeep-size Mars rover Curiosity, due to launch in late November, will be powered by more than 10 pounds of plutonium. Despite safety efforts, there's always the question of public safety if an explosion occurred.
NASA's Grail mission — twin spacecraft to be launched next month to Earth's moon — employs solar panels.