Dawn Interplanetary Spacecraft

Dawn, Orbital's first planetary spacecraft, was launched on September 27, 2007 aboard a Delta II rocket from Florida's Kennedy Space Center. Dawn will rendezvous, orbit and study the two largest asteroids in our solar system in a never-before-attempted mission to advance our understanding of how the planets were formed. The eight-year, 3.2-billion-mile odyssey is also NASA's first purely scientific mission powered by ion propulsion, the most advanced and efficient space propulsion technology, and the first spacecraft to orbit two planetary bodies during a single mission.

About the Mission
Orbital is partnered with Principal Investigator Dr. Christopher Russell of UCLA and the Jet Propulsion Laboratory (JPL) for this mission, which is funded by NASA's Discovery Program. Dawn will study the two largest known asteroids located in the "main belt" between Mars and Jupiter: Vesta and Ceres. Earth-based studies indicate that these two protoplanets have very different compositions, but have remained intact since their formation more than 4.5 billion years ago, offering a potential window into the formation of our solar system.

After a five year journey from Earth, Dawn will rendezvous with and orbit Vesta for eight months, conducting remote-sensing observations using a suite of advanced instruments. It will then depart Vesta and travel to Ceres to make the same types of measurements, arriving at the second asteroid in 2015.

About the Spacecraft
The Dawn spacecraft is a fully redundant, low-risk design that incorporates flight-proven components and subsystems from Orbital's STAR™ and LEOStar™ spacecraft busses as well as from NASA's Deep Space 1. Missions from which Dawn traces its heritage include GALEX, SORCE, Deep Space 1, OrbView, FUSE, IndoStar-1 and Topex/Poseidon. With its solar arrays deployed, Dawn measures approximately 19.7 meters (65 feet) from tip to tip. Mass at launch is approximately 1210 kg (2668 lbs).

Dawn is powered by a solar electric ion propulsion system pioneered on NASA's Deep Space 1 mission. Ion propulsion will provide the additional velocity needed to reach the main asteroid belt after the spacecraft separates from its launch vehicle, and be used to raise and lower the spacecraft's orbit during maneuver operations near the asteroids.

Dawn carries several scientific instruments, including a framing camera, a visible and infrared mapping spectrometer, and a gamma ray and neutron detector, in order to study Vesta and Ceres. Dawn will relay information obtained from these instruments back to Earth via a deep space communications network.


For more information:
DAWN Web Page
DAWN Fact Sheet
JPL Dawn Website
NASA Dawn Images and Video