Once the spacecraft lost the scheduled communication with NASA's Deep Space Network for two times on Wednesday and Thursday, the U.S. space agency officially declared the mission as "ended". Associate administrator, Thomas Zurbuchen from the NASA science mission directorate in Washington, hailed Dawn's "incredible technical achievements" and "vital science".
Launched 27 September 2007, the Dawn machine was created to study the asteroid Vesta and the dwarf planet Ceres. That way, in case NASA wants to send a follow-up mission, Dawn will not collide with Ceres before they do, keeping the planet free from human-and bacterial-contamination.
"The fact that my car's license plate reads "my other vehicle is in the asteroid belt" shows how proud I am of Dawn", said Dawn mission's director and chief engineer Marc Rayman.
Having traveled some 4.3 billion miles over the course of its 11-year mission, it's hard to say it had a bad innings, but it's a sad ending all the same. It is expected to remain in orbit around Ceres for decades, but will no longer be able to communicate with Earth as it ran out of fuel.
It's the second historic NASA mission this week to run out of fuel and come to an end, as NASA's Kepler Space Telescope did Tuesday. Dawn is the first spacecraft to orbit two extra-terrestrial bodies, the first spacecraft to visit either Vesta or Ceres, and the first to visit a dwarf planet, arriving at Ceres in March 2015, a few months before New Horizons flew by Pluto in July 2015.
The data Dawn beamed back to Earth from its four science experiments enabled scientists to compare two planet-like worlds that evolved very differently.
The Dawn orbiter has been flying around the dwarf planet Ceres for some time now. "Dawn's data sets will be deeply mined by scientists working on how planets grow and differentiate, and when and where life could have formed in our solar system", said Principal Investigator Carol Raymond at JPL. "Ceres and Vesta are important to the study of distant planetary systems, too, as they provide a glimpse of the conditions that may exist around young stars".
The Dawn mission launched in September 2007.
Dawn produced a complete map of the surface of Ceres and discovered ice volcanoes.
Zurbuchen said the scientific learning from Dawn's mission will go on. The craft will continue to orbit Ceres for at least 20 years, though many on the team put that number closer to 50.