Upcoming missions with Earth flybys include BepiColombo with its Earth flyby due in April 2020. The spacecraft also performed two asteroid flybys. Six spacecraft have been launched to explore Jupiter, with spacecraft making gravity-assist flybys. It was the first spacecraft to perform flybys of multiple planets. The orbits were designed for close up flybys of Jupiter's largest moons. The orbits were designed for close-up flybys of Jupiter's largest moons. After two Earth flybys, lunar insertion was achieved approximately one month after launch. For further examples of "Cassini" flybys of Saturn's moons see Timeline of "Cassini-Huygens". Its trajectory was designed to allow flybys of Jupiter, Saturn, Uranus, and Neptune. It was one of the 10 closest comet flybys of Earth in 70 years. Several close flybys of Callisto are planned during the mission. This hypothesis was confirmed by "Cassini's" first two close flybys in 2005. Three missions were flybys, which formed an extended foundation of knowledge about the system. A sequence of six Mercury flybys will lower the relative velocity to . These upgrades proved crucial in enabling the second and third Mercury flybys.