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NASA has confirmed that its Dawn spacecraft has died, one of the most underappreciated missions of recent times.
The spacecraft was in orbit around the dwarf planet Ceres, the largest object in the asteroid belt. But attempts to contact it this week failed, suggesting the spacecraft had run out of fuel, as has been expected to happen.
Dawn launched in 2007 on a mission to study another object in the asteroid belt, the large asteroid Vesta. It arrived in 2011, becoming the first spacecraft to orbit a body in the asteroid belt. It left Vesta in 2012 and arrived at Ceres in 2015 – next becoming the first spacecraft to orbit two bodies outside of the Earth-Moon system, a true interplanetary spacecraft.
"The fact that my car's license plate frame proclaims, 'My other vehicle is in the main asteroid belt,' shows how much pride I take in Dawn," said Mission Director and Chief Engineer Marc Rayman at NASA's Jet Propulsion Laboratory (JPL), California in a statement.
"The demands we put on Dawn were tremendous, but it met the challenge every time. It's hard to say goodbye to this amazing spaceship, but it’s time."
Aside from completing a lot of firsts, Dawn conducted a host of interesting science. Perhaps its most famous discovery was that of bright spots on Ceres – believed to be caused by salts, but possibly also indicative of an ancient ocean. Dawn’s studies of Ceres have shown it could be possible for dwarf planets to have oceans.
And by studying both Vesta and Ceres, with the former orbiting slightly closer to the Sun than the latter, Dawn has learned how important location is for the formation and evolution of a world.
“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,” Carol Raymond, the Principal Investigator on the mission, said in the statement.
“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.”
Dawn’s fate will not be like that of Cassini, which was purposefully crashed into Saturn last year. Instead, owing to planetary protection rules, it will be left in a “parking orbit” above Ceres for at least 20 years. This number was picked to allow enough time for a follow-up mission to Ceres before Dawn could contaminate it.
But now, after a journey of 6.9 billion kilometers (4.3 billion miles), the Dawn mission is over. It was our first mission to a dwarf planet, and the first for a lot of other things. It may not have had the popularity of Cassini or the recently lost Kepler mission, but Dawn will be equally missed by many.
