However, two spacecraft have flown by Ganymede and provided valuable information about it:

* Voyager 1 and 2: In 1979, both Voyager spacecraft flew past Jupiter and its moons, including Ganymede. They captured the first close-up images of the moon and provided data on its size, composition, and magnetic field.

* Galileo: This spacecraft orbited Jupiter from 1995 to 2003 and made several close flybys of Ganymede. It provided detailed information about the moon's surface, atmosphere, and internal structure.

While no dedicated missions to Ganymede have been launched, NASA's upcoming Europa Clipper mission will make multiple flybys of Ganymede during its mission to explore Jupiter's moon Europa. This will provide further valuable data about Ganymede, potentially paving the way for a future dedicated mission.