Roughly two years from now, the Dawn spacecraft will enter orbit around the asteroid Vesta. It is one of the most exciting missions of space exploration currently underway, venturing into regions of the Solar System that have never previously been explored. It will become the first spacecraft to orbit multiple worlds beyond the Earth, and will utilize advanced new technologies. The objective of the Dawn mission is to go into orbit and intensively study two major asteroids: Vesta and Ceres, the latter technically being defined as a dwarf planet.
The mission was launched in 2007, and has been sailing through the Solar System since then, powered by its remarkable ion engine. It flew past Mars in February of 2009, using its gravity to "slingshot" it along on its orbital path. If all goes well, Dawn will arrive at Vesta in September of 2011, depart a few months later, and arrive at Ceres in February of 2015. The information that will be sent back by the Dawn spacecraft will be a scientific treasure trove.
Studying the asteroids serves three major purposes. First, scientific knowledge is good in and of itself, contributing to the greater human understanding of the universe. Second, asteroids represent a small but real risk to the safety of Earth, and knowing more about them might one day prove priceless to the human race in the event that we discover that an asteroid is on a collision course with our planet. Finally, as the human race expands into the Solar System, the resources of raw materials present in the Asteroid Belt will prove to be of great value. The more we know about them, the better.
Thomas Jefferson was a strong proponent of exploration and discovery, which is why he sent the Lewis and Clark Expedition, among many other missions, to explore the American West. If he could see the activities of the modern American government, he would disapprove of a great deal, but he would excitedly approve of the activities of NASA. The 21st Century Jeffersonian should follow the course of the Dawn mission with great interest and excitement.
Watch this short documentary, made a few months before the launch of the Dawn mission, that provides an excellent background to the mission and its goals.