Exploration of Jupiter Exploration of Jupiter The exploration of Jupiter has been conducted via close observations by automated spacecraft. It began with the arrival of "Pioneer 10" into the Jovian system in 1973, and, , has continued with eight further spacecraft missions. All of these missions were undertaken by the National Aeronautics and Space Administration (NASA), and all but two have been flybys that take detailed observations without the probe landing or entering orbit. These probes make Jupiter the most visited of the Solar System's outer planets as all missions to the outer Solar System have used Jupiter flybys to reduce fuel requirements
Human mission to Mars were for a launch sometime between 2016 and 2020. The Mars probe would carry a crew of four to five cosmonauts, who would spend close to two years in space. In late 2011, Russian and European space agencies successfully completed the ground-based MARS-500. The biomedical experiment simulating crewed flight to Mars was completed in Russia in July 2000. In 2011, Jean-Marc Salotti published a new proposal for a crewed Mars mission, with a release in 2012. The 2-4-2 concept is based on a reduction of the crew size to only 2 astronauts and the duplication of the entire mission. There