The Juno spacecraft's set to lift off today on its way to Jupiter, with scientists hopeful that the mission will help answer questions about the formation of the solar system.
"The special thing about Juno is we're really looking at one of the first steps, the earliest time in our solar system's history," says Scott Bolton, principal investigator for the mission.
"Right after the sun formed, what happened that allowed the planets to form, and why are the planets a slightly different composition than the sun?"
The four-ton spacecraft will set off on its five-year journey atop a United Launch Alliance Atlas V rocket, equipped with five solid-fueled boosters. Even with that much power, it'll still require a flyby of Earth to get up enough energy to swing out to Jupiter. Three 34-foot-long solar arrays will be the sole power source.
The Atlas V has flown 28 times before.
"It's got a heritage that goes back to the Atlas I in some of the components and in the upper stage, so it's an evolution of a family in its current configuration and shape and form," says launch director Omar Baez. "I'd say it's pretty robust."
The spacecraft's due to lift off at 11:34 am today from Space Launch Complex 41 at Cape Canaveral Air Force Station in Florida.
"Juno only has a 22-day launch window, or else we're down for another 13 months until our next opportunity," says mission manager John Calvert.
After arriving at Jupiter in August 2016, the spacecraft will spend about a year surveying Jupiter and its moons to draw a detailed picture of its magnetic field and find out whether there is a solid core beneath its multi-colored clouds.
It may also provide clues about what to look for in planets outside the solar system.
"If we could start to understand the role that Jupiter played and how the planet formed and how that eventually governed the creation of the other planets and the Earth and maybe even life itself, then we know a little bit about how to look for other Earth-like planets, maybe orbiting other stars and how common those might be and the roles that those giant planets that we see orbiting the other stars play," says Bolton.