Space policy and the size of the space shuttle fleet

During the space shuttle era, policy makers have repeatedly wrestled with the issue of fleet size. The number of shuttles had both practical and symbolic significance, reflecting the robustness of the space transportation system and US preeminence in space. In debating how many shuttles were needed, NASA and other government entities weighed various arguments to determine the optimum number of vehicles for human spaceflight. Deliberations and decisions about shuttle fleet size reflected changing policy priorities and attitudes about the role of the shuttle. That history frames issues that may arise again in planning for new space transportation vehicles beyond the shuttle.     

The Dawn Spacecraft

The Dawn spacecraft is designed to travel to and operate in orbit around the two largest main belt asteroids, Vesta and Ceres. Developed to meet a ten-year life and fully redundant, the spacecraft accommodates an ion propulsion system, including three ion engines and xenon propellant tank, utilizes large solar arrays to power the engines, carries the science instrument payload, and hosts the hardware and software required to successfully collect and transmit the scientific data back to Earth. The launch of the Dawn spacecraft in September 2007 from Cape Canaveral Air Force Station was the culmination of nearly five years of design, development, integration and testing of this unique system, one of the very few scientific spacecraft to rely on ion propulsion. The Dawn spacecraft arrived at its first destination, Vesta, in July 2011, where it will conduct science operations for twelve months before departing for Ceres.     

Development of educational CD-ROMs in astronomy: Information on a collaborative project

The observatory of Paris and the institute of teacher training (IUFM) in Toulouse have collaborated to develop multimedia support for astronomy lessons. The goal of this project is to provide additional didactical material such as CD-ROMs to elementary and high school teachers which will be used by children in the classroom. In this paper, we present the aims of the project and describe briefly the contents that have been developed so far.