Unmanned Earth orbiting satellites and robotic exploratory spacecraft to the planets, comets, asteroids, and the sun. Sites pertaining to past, current, and future or proposed missions may be included in this category.
Space missions studying the outer planets (Jupiter, Saturn, Uranus, Neptune, and Pluto), the Kuiper Belt, Oort Cloud, and outer regions of the solar system.
Solar sails are made of thin reflective material and use sunlight for photonic propulsion. Although potentially usable for interstellar travel, they are still in testing for terrestrial orbit.