NASA's Lucy spacecraft will be hurled into space on a 12-year expedition to study a record number of asteroids.
NASA is set to launch a first-of-its kind mission, dubbed Lucy, to study Jupiter's Trojan asteroids, two large clusters of space rocks that scientists believe are remnants of primordial material that formed the solar system's outer planets.
The space probe, packed inside a special cargo capsule, is due for liftoff from Cape Canaveral Air Force Station in Florida early Saturday morning carried aloft by an Atlas V rocket from United Launch Alliance.
Lucy will be the first to explore the Trojans, thousands of rocky objects orbiting the sun in two swarms - one ahead of the path of giant gas planet Jupiter and one behind it.
Hope for new clues
The largest known Trojan asteroids, named for the warriors of Greek mythology, are believed to measure as much as 225 kilometres in diameter.
Scientists hope Lucy's close-up fly-by of seven Trojans will yield new clues to how the solar system's planets came to be formed some 4.5 billion years ago and what shaped their present configuration.
Believed to be rich in carbon compounds, the asteroids may even provide new insights into the origin of organic materials and life on Earth, NASA said.
"The Trojan asteroids are leftovers from the early days of our solar system, effectively the fossils of planet formation," principal mission investigator Harold Levison of the Southwest Research Institute in Boulder, Colorado, was quoted by NASA as saying.
No other single science mission has been designed to visit as many different objects independently orbiting the sun in the history of space exploration, NASA said.