Dawn

Spacecraft· NASAinactive

Dawn — used ion propulsion to orbit two protoplanets, Vesta (2011–2012) then Ceres (2015–2018); the first mission to orbit a dwarf planet.

Open in 3D viewSee Dawn in the live, interactive 3D map

Key facts

Current speed

95.4 m/s

Distance from Sun

2.71 AU

Status

Completed

Launched

2007

Mission & specifications

Mission

Operator: NASA
Launched: September 27, 2007
Status: Completed

Trajectory

Current speed: 95.4 m/s
Distance from the Sun: 2.71 AU
Distance from Earth: 3.15 AU
Distance from Mars: 1.25 AU

Cost & funding

Program cost: $4.67 × 10⁸ USD

Mission

Dawn was the first spacecraft to orbit two different worlds beyond Earth, a feat made possible by its efficient ion engines. Launched on 27 September 2007, it set out to study the two largest bodies in the asteroid belt — Vesta and Ceres — which are survivors from the dawn of the Solar System, frozen at an early stage of planet-building. Dawn reached Vesta in July 2011 and orbited it for fourteen months, mapping a dry, battered, rocky world dominated by an enormous impact basin at its south pole, whose excavation had flung out debris that still falls to Earth as meteorites. Then it did what no spacecraft had done before: it broke orbit and cruised onward under gentle ion thrust to a second destination, arriving at Ceres in March 2015 to become the first spacecraft to visit a dwarf planet. Ceres proved very different — an icy, clay-rich world with mysterious bright spots in a crater called Occator, which turned out to be deposits of salt left behind by briny water that had welled up from below, hinting at a subsurface reservoir and a still-evolving interior. Dawn studied Ceres until its fuel for pointing ran out, falling silent in October 2018. It remains in a long, stable orbit around Ceres, a silent monument that will circle the dwarf planet for decades.

2007Launch toward the asteroid beltLaunch
An ion-powered probe sets out to orbit two worlds — Vesta and Ceres.
2011Orbits VestaOrbiter
Maps a dry, battered protoplanet dominated by a giant south-polar impact basin.
2012Departs Vesta for CeresMilestone
Breaks orbit under ion thrust — the first craft to orbit one world and cruise to another.
2015Orbits CeresArrival
Becomes the first spacecraft to visit a dwarf planet.
2015Bright salts on CeresMilestone
The bright spots in Occator crater prove to be salt left by briny water from below.
2018Falls silent at CeresMission end
Out of pointing fuel, Dawn ends its mission but remains in a stable orbit for decades.

Images

Artist Rendering of NASA Dawn Spacecraft Approaching Mars — NASA/JPL-Caltech · NASA Image Library

NASA Dawn Spacecraft Headed for Vesta Artist Concept — NASA/JPL-Caltech · NASA Image Library

Dawn Spacecraft Being Assembled — NASA/JPL · NASA Image Library

Dawn Spacecraft — NASA/McREL · NASA Image Library

Dawn Spacecraft in Thermal Vacuum Chamber — NASA/JPL · NASA Image Library

Illustration of Dawn Spacecraft Inside View — NASA/JPL/Orbital Sciences Corporation · NASA Image Library

Delta II rocket carrying NASA's Dawn spacecraft launches from pa — NASA\ Tony Gray · NASA Image Library

Dawn LAMO Image 66 — NASA/JPL-Caltech/UCLA/MPS/DLR/IDA · NASA Image Library

Images from open archives · credit shown per image