The plasmasphere is a region of enduring scientific interest and considerable practical importance. A number of communications, navigation, and military satellites that are becoming indispensable to routine human activities are stationed in this region.
To ensure the reliability of these assets, it is important to understand the plasmaspheric environment comprehensively Recently, there has been renewed interest in the plasmasphere as evidenced by a number of imaging missions, such as the NASA/Imager for Magnetopauseto-Aurora Global Exploration (IMAGE), the U.S. Department of Defense/Advanced Research & Global Observation Satellite (ARGOS), and the proposed Magnetospheric Imager (MI), whose objectives include imaging the plasmasphere. To fully use the information obtained by remote sensing, we must develop more accurate models of the plasmaspheric structure than are currently available. Hence, an emphasis on plasmaspheric research is particularly timely.