Dawn mission to die another day
Spacecraft glitch delays upcoming trip to Ceres
By Nadia Drake
A mechanical glitch on NASA’s Dawn spacecraft will delay the next leg of its voyage through the asteroid belt. But the defect shouldn’t keep the probe from completing its mission with a visit to the dwarf planet Ceres.
On August 13, the Jet Propulsion Laboratory announced that Dawn had lost the second of its four initial reaction wheels. Electrically controlled by onboard systems, these wheels precisely aim the spacecraft so it can acquire images and data. Dawn is tasked with taking detailed measurements of two targets: the enormous asteroid Vesta, where it’s been for the last year, and the dwarf planet Ceres, its next destination.