It’s a new day for the Dawn spacecraft. The NASA spacecraft, which has been orbiting the dwarf planet Ceres since 2015, just got its final marching orders: Keep orbiting Ceres indefinitely.
The extension, which NASA announced October 19, will be the second time Dawn’s mission at Ceres has been renewed. It means Dawn will still be in orbit when Ceres makes its closest approach to the sun in April 2018. At that point, ice on Ceres’ surface may turn to water vapor. The spacecraft will also move to lower altitudes over the dwarf planet than ever before, swooping as low as 200 kilometers above the surface. Dawn will use its onboard mass spectrometer to learn more about how much ice is hidden in Ceres’ surface.
Dawn will stay in a stable orbit around Ceres after it runs out of fuel in the second half of 2018. Other options would have been to move the spacecraft on to a new space rock — like Dawn itself did when it left the asteroid Vesta for Ceres in 2012 — or deliberately crash it, like the Rosetta spacecraft did in 2016.