The DAWN Spacecraft has finished it’s study of the asteroid Vesta and will be continuing on to study another large asteroid named Ceres in 2015. The DAWN spacecraft arrived at Vesta on July 15, 2011 and has been mapping and studying the asteroid in detail ever since. The data collected shows that Vesta resembles a small planet more than a typical asteroid and is thought to be a surviving baby planet from the birth of the solar system. This includes an iron core at the center which probably means that it had completely melted at one point in its past. The mapping also included many asteroid impacts including two large impacts near the south pole which actually caused permanent ripples throughout the asteroid.
The DAWN spacecraft uses ion propulsion which allows it to get around the solar system quite efficiently. This engine ionizes Xenon and accelerates small amounts of it at very high velocity. This allows for a small but very constant acceleration as this type of propulsion can operate for years at full thrust due to it extreme fuel conservation. The acceleration produced is similar to the amount of force that a piece of paper exerts on your hand if you were holding it and that’s why it’s going to take until 2015 before it can reach Ceres. While this type of propulsion isn’t ideal for transporting humans from one place to another quickly, it’s ideal for maximizing travel around the solar system by robotic missions with no time limit.
While the asteroid belt isn’t a major planet, it does offer opportunities. We have been able to test out the ion drive on a long mission which will allow us to improve future versions. Studying large asteroids and dwarf planets in detail help us understand the formation of our solar system and other planetary systems that we are discovering. Asteroid mining is a future possibility so knowledge of asteroids and their minerals is essential for development of future plans. It may even one day be possible to set up outposts on large asteroids like Vesta to enable travel to the outer solar system. The DAWN spacecraft has only finished it’s first steps in solar system exploration so we’ll have to wait and see what new wonders it can show us.