Exploratory missions to other planets within the local system. Ever since the moon landings, people have dreamed of sending manned missions to other planets, most noteably Mars. However, due to the extreme cost of getting people onto other planets and somehow persuading them to stay alive at the same time, all interplanetary expeditions have been made by robotic probes. Such probes like Mariner 10, Voyager 1, and Voyager 2 have all traveled to other planets but simply passed by, making a grand sweep of the solar system to gather data on multiple celestial bodies. With this data, scientists have been able to plan more specialized expeditions to individual planets. The Viking landers, the Mars Observer, which was lost, the Mars Global Surveyor, and the Sojourner missions all were focused on, duh, Mars. The Galileo probe arrived at Jupiter in December of 1995, and has produced a plethora of data on Jupiter and its moons, including Io, the most volcanically active body in the solar system, and Europa, which many scientists believe has an ocean of liquid water below its icy surface, and, quite possibly, extraterrestrial life. Galileo is currently studying the effects of solar wind on Jupiter's magnetic field in conjunction with the Cassini spacecraft.

Future missions planned include: