The spacecraft Dawn has successfully reached its low orbit of 230 kilometers above the asteroid Vesta, for intense scientific research.
The primary instruments at this level will be the gamma ray and neutron detector (GRaND) and the gravity experiment. Currently, scientists expect Dawn to spend ten (10) weeks at this altitude. The objective is to determine the kinds of material (atoms) on the surface of Vesta and measure the gravitational field of the asteroid. Scientists want to determine the distribution of masses within Vesta.
Marc Rayman, Dawn’s chief engineer and mission manager based at NASA’s Jet Propulsion Laboratory, Pasadena, California noted:
Dawn has performed some complicated and beautiful choreography in order to reach this lowest orbit.” We are in an excellent position to learn much more about the secrets of Vesta’s surface and interior.
After this data collection period, Dawn will spiral outward to a new orbit around 680 kilometers above the surface for another high altitude mapping campaign. The Sun will then be higher in the northern regions of Vesta fir better imaging.
Dawn plans to leave Vesta in July 2012 and arrive at its second destination, the dwarf planet named Ceres, in February 2015.