Missions to Comets and Asteroids

Abstract

For the greater part of the history of space exploration, now only just forty years in extent, the small bodies in our Solar System have been relatively ignored. The focus of attention in planetary exploration has been on the nearest planets to Earth, Mars and Venus, and on the large, dominant planets of the Outer Solar System, Jupiter, Saturn, Uranus and Neptune. Even the smallest planets Mercury and Pluto have been relatively ignored. There has been only one mission to Mercury, Mariner 10 in 1973, a multiple flyby mission which imaged only one hemisphere of the small planet. Pluto has yet to be explored by spacecraft and will not be visited until more than 50 years have past since the dawn of the space age. The Pluto mission, now scheduled by NASA for launch in 2003 and flyby in 2011, will mark the end of the reconnaissance phase of exploring the planetary region of the Solar System.