This paper describes unmanned missions planned in support of NASA’s Space Science Enterprise over the next ten years. It focuses on smaller, focused missions employing advanced technology in order to achieve significant science return at a reduced cost and duration such as the Discovery and Small Explorer programs now in place and the next generation of small missions now being planned. These next generation missions will continue to build upon the expeditionary nature of the original flagship missions through the focused investigation of specific phenomena or features of interest, using small, inexpensive, highly integrated spacecraft, costing an order of magnitude less than past missions and developed in a fraction of the time. © 1995American Institute of Physics