NASA postpones Dawn spacecraft launch

The launch of NASA's Dawn spacecraft was postponed Monday because of weekend fueling delays.

National Aeronautics and Space Administration officials said the Wednesday launch of the spacecraft aboard a Delta II rocket from the Kennedy Space Center was postponed 24 hours because fueling of the rocket's second stage was unable to be completed Sunday because of weather conditions.

The launch was re-scheduled for a 29-minute span beginning at 7:20 a.m. EDT Thursday.

Dawn's goal is to characterize the cosmology of the solar system's earliest epoch 4.5 billion years ago by investigating the massive asteroid Vesta and the dwarf planet Ceres, both of which are in the asteroid belt between Mars and Jupiter.

Scientists theorize Vesta and Ceres were budding planets that followed different evolutionary paths during the solar system's first few million years. By investigating two diverse asteroids during its eight-year flight, the Dawn mission is expected to resolve some of the mysteries of planetary formation.

Dawn is designed to become the first spacecraft to orbit an object in the asteroid belt and the first to orbit two bodies after leaving Earth.