http://space.com/news/planetarymissions/robot_outposts_991116.html
To quote in part:
PASADENA, Calif. - To further extend humankind’s reach into the cosmos
during the next century, future planetary missions will depend on
establishing
robotic outposts, Edward Stone, director of the NASA Jet Propulsion
Laboratory
said Tuesday.
Speaking at the 46th annual meeting of the American Astronautical Society, Stone said such outposts are a necessary next step in the 40-year history of exploring the solar system.