DAWN

Mission Profile

Dawn is a NASA Discovery-class mission launched on 27 September 2007 aboard a Delta II 7925H, the first spacecraft to orbit two extraterrestrial bodies — the giant asteroid Vesta and the dwarf planet Ceres — using an ion propulsion system that provided extraordinary fuel efficiency over its decade-long mission. At Vesta from 2011-2012, Dawn revealed a geologically diverse world with ancient craters and evidence of a differentiated interior including an iron core. At Ceres from 2015-2018, Dawn discovered mysterious bright spots in Occator Crater identified as deposits of sodium carbonate brine from a subsurface reservoir, as well as the 4-km tall Ahuna Mons cryovolcanic dome. Dawn ran out of hydrazine attitude control propellant in October 2018, ending its mission in orbit around Ceres where it will remain for at least two decades.