Next for NASA: Solar-powered Jupiter probe

CAPE CANAVERAL, Fla. -- 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. Scientists hope to learn more about planetary 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 blueprint would have astronauts reach an asteroid by 2025 and Mars a decade later. NASA's Grail mission -- twin spacecraft to launch next month to the moon -- employs solar panels.