Propulsion trades for space science missions

This study evaluated the relative benefits of proposed deep space propulsio n technology improvements in three areas: advanced chemical, solar electric , and solar sail. Within each area, specific states, representing current t echnology (present-1999), mid-term (2000-2004), and far term (2005+), were selected for evaluation. The figures of merit used were net spacecraft mass delivered, size of the launch vehicle needed, trip time, cost, and risk. B ased on the results, an investment strategy was recommended to NASA headqua rters, along with possible scenarios for its implementation. (C) 1999 Publi shed by Elsevier Science Ltd. All rights reserved.