NASA's Dawn Mission to Asteroid Belt Comes to End
NASA declares Dawn's historic mission over after spacecraft depletes its hydrazine fuel and stops communicating with the Deep Space Network.
NASA's Dawn
spacecraft has gone silent, ending a historic mission that studied time
capsules from the solar system's earliest chapter.Dawn missed
scheduled communications sessions with NASA'sDeep
Space Networkon Wednesday, Oct. 31, and Thursday,
Nov. 1. After the flight team eliminated other possible causes
for the missed communications, mission managers concluded that the spacecraft
finally ran out of hydrazine, the fuel that enables the spacecraft to control
its pointing. Dawn can no longer keep its antennae trained on Earth to
communicate with mission control or turn its solar panels to the Sun to
recharge.NASA's Dawn spacecraft turned science fiction into science fact by using ion propulsion to explore the two largest bodies in the main asteroid belt, Vesta and Ceres. The mission will end this fall, when the spacecraft runs out of hydrazine, which keeps it oriented and in communication with Earth.The Dawn
spacecraftlaunched11 years ago to visit the two largest objects in the main asteroid belt. Currently,
it's in orbit around the dwarf planet Ceres, where it will remain for decades."Today, we
celebrate the end of our Dawn mission - its incredible technical achievements,
the vital science it gave us, and the entire team who enabled the spacecraft to
make these discoveries," said Thomas Zurbuchen, associate administrator of
NASA's Science Mission Directorate in Washington. "The astounding images
and data that Dawn collected from Vesta and Ceres are critical to understanding
the history and evolution of our solar system."Dawn launched
in 2007 on a journey that put about 4.3 billion miles (6.9 billion kilometers)
on its odometer. Propelled by ion engines, the spacecraft achievedmany
firstsalong the way. In 2011, when Dawn arrived at Vesta, the
second largest world in the main asteroid belt, the spacecraft became the first
to orbit a body in the region between Mars and Jupiter. In 2015, when Dawn went
into orbit around Ceres, a dwarf planet that is also the largest world in the
asteroid belt, the mission became the first to visit a dwarf planet and go into
orbit around two destinations beyond Earth."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.
"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."The data Dawn
beamed back to Earth from itsfour science
experimentsenabled scientists to compare two planet-like worlds
that evolved very differently. Among its accomplishments, Dawn showed how
important location was to the way objects in the early solar system formed and
evolved. Dawn also reinforced the idea that dwarf planets could have hosted
oceans over a significant part of their history - and potentially still do."In many
ways,Dawn's legacyis
just beginning," said Principal Investigator Carol Raymond at JPL. "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.
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."Because Ceres
has conditions of interest to scientists who study chemistry that leads to the
development of life, NASA follows strict planetary protection protocols for the
disposal of the Dawn spacecraft. Dawnwill remain in
orbitfor at least 20 years, and engineers have more than 99 percent
confidence the orbit will last for at least 50 years.So, while the
mission plan doesn't provide the closure of a final, fiery plunge - the way NASA'sCassinispacecraft ended last year, for example - at least this is certain: Dawn spent
every last drop of hydrazine making science observations of Ceres and radioing
them back so we could learn more about the solar system we call home.The
Dawn mission is managed by JPL for NASA's Science Mission Directorate in
Washington. Dawn is a project of the directorate's Discovery Program, managed
by NASA's Marshall Space Flight Center in Huntsville, Alabama. JPL is
responsible for overall Dawn mission science. Northrop Grumman in Dulles,
Virginia, designed and built the spacecraft. The German Aerospace Center, Max
Planck Institute for Solar System Research, Italian Space Agency and Italian
National Astrophysical Institute are international partners on the mission
team.The
Dawn media toolkit, with a mission timeline, images, video and quick facts, is
available here:https://dawn.jpl.nasa.gov/mission/toolkitWatch
the video "Dawn: Mission to Small Worlds," with NASA Chief Scientist
Jim Green, at:https://www.youtube.com/watch?v=JrafypeEhTMMore
information about Dawn is available at:https://www.nasa.gov/dawn