CAPE CANAVERAL — A sun-powered robotic explorer named Juno is rocketing toward Jupiter on a fresh quest to discover the secret recipe for making planets.
An Atlas rocket carrying Juno blasted into a clear midday sky Friday. It will take five years for Juno to reach Jupiter, the solar system's most massive and ancient planet.
Within an hour of liftoff, Juno hurtled out of Earth's orbit at 24,000 mph on a roundabout course for Jupiter. It was expected to whip past the orbit of the moon in half a day, or early this morning.
It is the first step in Juno's 1.7 billion-mile voyage to the gas giant Jupiter, just two planets away but altogether different from Earth and next-door neighbor Mars.
Juno is solar powered, a first for a spacecraft meant to roam so far from the sun. The three huge solar panels popped open an hour into the flight, each one stretching as long and wide as a semitrailer truck. Previous spacecraft to the outer planets have relied on nuclear energy.
With Juno, scientists hope to answer some of the most fundamental questions of our solar system.
Jupiter is so big it could contain everything in the solar system, minus the sun, and still be twice as massive.
Juno will venture much closer to Jupiter than any of the eight spacecraft that have visited since the 1970s, most of them just passing by. It's by far the most focused and elaborate Jupiter mission.
The $1.1 billion mission will end with Juno taking a fatal plunge into Jupiter in 2017.
With the end of the space shuttle program just two weeks ago, Juno's liftoff created more buzz than usual. Several thousand invited guests jammed Kennedy Space Center to watch the Atlas V blast off from Cape Canaveral Air Force Station next door..