A joint NASA-ESA study of potential missions to Uranus and Neptune has been released. The study was performed as part of preparations for the next Planetary Science Decadal Survey. It identifies the scientific questions the next Ice Giant mission should address, and discusses
various instruments, spacecraft, flight-paths, and technologies that could be used. The full study as well as an Executive Summary are available at: http://www.lpi.usra.edu/icegiants/mission_study