The Dawn probe, which has been orbiting the dwarf planet Ceres, won’t be visiting another object in the asteroid belt, as the engineering team had hoped. Instead, the spacecraft will remain at Ceres, where it has been stationed for the past year.
The engineering team hoped to send their probe to another asteroid
The Dawn spacecraft completed its primary mission at Ceres yesterday, but the engineering team hoped to send their probe to another asteroid called Adeona. The mission team had even come up with ways to conserve the spacecraft’s hydrazine fuel to pull off the flyby, according to Space News. If the mission had been approved, the spacecraft would have started spiraling out from Ceres this month. After leaving the dwarf planet, Dawn would have orbited the Sun for a few years and then would have visited Adeona in May 2019.
But NASA officials decided Dawn would be better served at Ceres instead. "The long-term monitoring of Ceres, particularly as it gets closer to perihelion – the part of its orbit with the shortest distance to the Sun -- has the potential to provide more significant science discoveries than a flyby of Adeona," Jim Green, NASA’s Director of Planetary Science, said in a statement. The decision to remain at Ceres was made by NASA’s 2016 Planetary Mission Senior Review Panel.
There was some confusion over the Adeona mission
Before this announcement, there was some confusion over whether NASA had actually approved the Adeona mission. An update was posted to the Dawn website last night, confirming that Dawn would be visiting Adeona in 2019. That post was taken down only minutes later; NASA admitted its posting was a mistake, according to Wired. Then today, the space agency announced that Dawn wouldn’t be leaving Ceres, while announcing the extensions for New Horizons and seven other missions.
The Dawn spacecraft launched in 2007 on a Delta II rocket and became the first vehicle to visit and orbit the asteroid Vesta in 2011. After a year in orbit, Dawn left the space rock and journeyed to Ceres, the largest known object in the asteroid belt. The spacecraft entered Ceres’ orbit on March 2015 and over time has spiraled downward closer to the dwarf planet. Starting in October 2015, Dawn spent two months spiraling down to its lowest and final orbit, where it has remained ever since.