Dawn is Dead: NASA’s pioneering asteroid belt mission runs out of fuel


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Darkness has finally come for Dawn.

NASA’s Dawn spacecraft – which sent the two largest objects in the asteroid belt, Vesta and Ceres, into orbit in its long and accomplished life – is running out of fuel and has died, announced today. ‘hui (November 1) officials of the agency.

“Today we celebrate the end of our Dawn mission – her incredible technical achievements, the life science she gave us and the whole team that made the spacecraft make these discoveries,” Thomas Zurbuchen, Associate Administrator of NASA’s Directorate of Science Missions in Washington, DC, said in a statement. [Photos: Asteroid Vesta and NASA’s Dawn Spacecraft]

“The amazing images and data that Dawn has gathered from Vesta and Ceres are essential to understanding the history and evolution of our solar system,” Zurbuchen added.

Dawn’s death is the second quick punch for space fans. NASA officials said Tuesday, October 30, that the agency’s Kepler Space Telescope, which has discovered 70 percent of the 3,800 extraterrestrial planets known to date, was also out of fuel. Kepler will be downgraded in a week or two.

The $ 467 million Dawn mission launched in September 2007 to study the protoplanet Vesta and the dwarf planet Ceres, which are approximately 330 miles (530 kilometers) and 590 miles (950 km) wide, respectively. Scientists consider these two bodies to be vestiges of the period of formation of the planets in the solar system, which explains the name of the mission. (“Dawn” is not an acronym.)

Dawn arrived in Vesta in July 2011, then scanned the object from orbit for 14 months. The probe’s work revealed many intriguing details about Vesta. For example, liquid water once flowed over the surface of the protoplanet (likely after the ice buried by meteor impacts had melted), and Vesta sports a towering peak near its south pole which is almost as high as the famous Olympus Mons volcano from Mars.

Dawn left Vesta in September 2012. The probe arrived in Ceres in March 2015, becoming the first spacecraft to orbit a dwarf planet, and the first to encircle two bodies beyond the Earth-Moon system. Such spaceflight feats were made possible by Dawn’s super efficient ion engines, mission team members said.

“The demands we put on Dawn were enormous, but they rose to the challenge every time,” said Mission Director and Chief Engineer Marc Rayman, of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, in California, in the same release.

Dawn discovered a number of intriguing light spots on Ceres. Members of the mission team determined that these characteristics were salts, which were likely left behind when the brackish water in the basement boiled and soared into space.

The bright spots are young, suggesting Ceres had pockets of liquid water buried in the recent past – and probably even retains some today, mission team members said. The dwarf planet is therefore an intriguing target for astrobiologists, especially when another discovery from Dawn is taken into account: the probe has detected organic molecules, the building blocks of life containing carbon as we know it, at the surface of Ceres.

This photo of Ceres and one of its key landmarks, Ahuna Mons, was one of the last sights transmitted by NASA’s Dawn spacecraft before it depleted its remaining hydrazine and completed its mission. This view, which faces south, was captured on September 1, 2018, at an altitude of 2,220 miles (3,570 kilometers) as the spacecraft climbed into its elliptical orbit. (Image credit: NASA / JPL-Caltech / UCLA / MPS / DLR / IDA)

Dawn also spotted a 4 km high “lonely mountain”, by far the highest surface on the dwarf planet. This mountain, which has been called Ahuna Mons, is likely a cryovolcano that formed over the past hundreds of millions of years, mission scientists said.

“In many ways, Dawn’s legacy is just beginning,” mission principal investigator Carol Raymond, also of JPL, said in the same statement. “Dawn’s data sets will be deeply exploited by scientists working on how planets develop and differentiate, and when and where life might have formed in our solar system. Ceres and Vesta are also important to the study of distant planetary systems, as they provide insight into the conditions that may exist around young stars. “

The mission team concluded that Dawn ran out of hydrazine after the probe missed scheduled communications checks yesterday (October 31) and today. Hydrazine is the fuel used by Dawn’s aiming thrusters, so the spacecraft can no longer orient itself to study Ceres, relay data to Earth, or recharge its solar panels.

Dawn will remain in orbit around Ceres for at least 20 years, and probably much longer than that. Members of the mission team said there was a greater than 99% chance the probe would not spiral down the icy, battered Ceres surface for at least five more decades.

The deaths of Dawn and Kepler came as no surprise. Members of the mission team have known for months that the tanks of the two spacecraft were getting very dry.

Mike Wall’s book on the search for alien life, “The low, ” will be released on November 13 by Grand Central Publishing. Follow him on twitter @michaeldwall. Follow us @Spacedotcom Where Facebook. Originally published on Espace.com.


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