“Astrochicken, Dyson explained, is a one-kilogram spacecraft that is unlike any other. Astrochicken would be a creation of the intersection of biology, artificial intelligence and modern microelectronics—a symbiosis of plant and animal and electronic components. Astrochicken will be launched by a conventional spacecraft into space at which point it is akin to the egg being laid into space. Astrochicken would then hatch and start growing a solar energy collector. The solar collector would feed an ion drive engine that will power the craft. Once the Astrochicken enters a planet's vicinity, say Uranus, it will feed on the moons and rings of the planet taking in necessary nutrients. It can land and take off using an auxiliary chemical rocket similar to that used by bombardier beetles. Now and then when it is in radio contact with earth the chicken can call home and transmit details of its journey.”

http://en.wikipedia.org/wiki/Astrochicken