ASI - Agenzia Spaziale Italiana - Mission and Projects ASI - Agenzia Spaziale Italiana - Mission and Projects

DAWN

Main Theme Minor Bodies of the Solar System
Mission Responsibility NASA
Launch Date 27 September 2007
End of Mission July 2015 (nominal)
Current phase E2
Websites http://dawn.jpl.nasa.gov/
http://www.ifsi-roma.inaf.it/vir

 

Description
The Dawn mission was selected by NASA on 21 December 2001 within the framework of the Discovery Programme. Its objective is to study the asteroids Vesta and Ceres.
After it was launched on 27 September 2007, the spacecraft will perform a gravity assist manoeuvre with Mars in February 2009 and then head toward Vesta which it will reach in August 2011.

 

Following the insertion manoeuvre in its orbit, the spacecraft will study Vesta until May 2012 and then it will head toward Ceres, which it will reach in February 2015. The spacecraft will orbit around Ceres until July 2015.

 

Scientific Objectives
The mission is ideally positioned between the exploration of the internal rocky Solar System and the external gaseous Solar System. It completes the exploration of the internal Solar System since it is complementary to missions now in progress and future missions on Mercury, Venus, the Earth and Mars.  In particular it will improve our knowledge of water's role and importance in planetary evolution. The main scientific objectives of the mission are:
(1) to gather information on the conditions that were in force during the early phases of the Solar System's evolution, or rather the first millions of years in its evolution and the processes in play on the newly formed bodies,
(2) to describe the "bricks" from which the terrestrial planets are formed, thus increasing our knowledge of this process of formation.


Ceres is very primitive and preserves traces of water, unlike other minor planets.  It could also have a tenuous, but permanent atmosphere. Unlike Ceres, Vesta is evolved and dry, the only asteroid which shows evident signs of a complex thermal evolution similar to the terrestrial planets with the presence of volcano activity.
In order to reach its scientific objectives, Dawn must describe the asteroids observed in terms of form and physical properties (size, form, mass, period and rotation axis), morphological characteristics (local structures, crater distribution, the presence or not of Regolite), geological and mineral nature of the surface, presence or not of dusts and/or gases.

 

Italian Contribution
Italian participation to the mission will supply:
(1) an imaging spectrometer operating in visible and near infrared at high space and spectral resolution to carry out the hyperspectral mapping of the asteroids. VIR-MS "Visible-IR Mapping Spectrometer",  derived from the VIRTIS instrument on board the Rosetta mission, is under the responsibility of PI Angioletta Coradini (INAF/IFSI) and was built by Galileo Avionica, the prime contractor industry.
(2) the manpower of the Dawn Project Team at JPL/UCLA for in-flight operations.

 

International Agreements
On 19 December 2003 the cooperation for the development of the Dawn mission between ASI and NASA was formalized by the signing of a Letter of Agreement. Subsequently, a Memorandum of Understanding between NASA and ASI was signed, which entered into force on 6 July 2007.