Parker Solar Probe by the Helios 2 spacecraft. The "Parker Solar Probe" concept originates from a predecessor "Solar Orbiter" project conceived in the 1990s. Similar in design and objectives, the "Solar Probe" mission served as one of the centerpieces of the eponymous Outer Planet/Solar Probe (OPSP) program formulated by NASA. The first three missions of the program were planned to be: the "Solar Orbiter", the Pluto and Kuiper belt reconnaissance mission "Pluto Kuiper Express", and the "Europa Orbiter" astrobiology mission focused on Europa. The original "Solar Probe" design used a gravity assist from Jupiter to enter a polar orbit which dropped almost directly
Fictional planets of the Solar System Fictional planets of the Solar System The fictional portrayal of our Solar System has often included planets, moons, and other celestial objects which do not actually exist in reality. Some of these objects were, at one time, seriously considered as hypothetical planets which were either thought to have been observed, or were hypothesized in order to explain certain celestial phenomena. Often such objects continued to be used in literature long after the hypotheses upon which they were based had been abandoned. Other non-existent Solar System objects used in fiction have been proposed or hypothesized by persons with no scientific standing,