NASA's Dawn spacecraft, originally scheduled for launch on June 20th, is finally on its way to study a pair of asteroids after lifting off from the Cape Canaveral Air Force Station yesterday morning following a series of delays which steadily pushed the launch-date backwards. Mission controllers at NASA's Jet Propulsion Laboratory, Pasadena, Calif., soon received telemetry on schedule, indicating Dawn had achieved proper orientation in space and its massive solar array was generating power from the sun. "Dawn has risen, and the spacecraft is healthy," said the mission's project manager Keyur Patel of JPL. "About this time tomorrow [Friday morning], we will have passed the moon's orbit."
Dawn's 4.8-billion-kilometer (3-billion-mile) odyssey includes exploration of asteroid Vesta in 2011 and the dwarf planet Ceres in 2015, two icons of the asteroid belt have been witness to much of our solar system's history. Dawn's science instrument suite will measure elemental and mineral composition, shape, surface topography, and tectonic history, and will also seek water-bearing minerals. The spacecraft's engines use a unique, hyper-efficient system called ion propulsion, which uses electricity to ionize xenon to generate thrust. The 30-centimeter-wide (12-inch) ion thrusters provide less power than conventional engines but can maintain thrust for months at a time.
View: Press Release at NASA