The Galileo spacecraft was launched on October 18, 1989, aboard Space Shuttle Atlantis during the STS-34 mission. Following a complex trajectory that included a flyby of Venus and two flybys of Earth, Galileo's long journey culminated in its arrival at Jupiter on December 7, 1995. The mission aimed to explore Jupiter's atmosphere, its massive magnetic field, and its moons, particularly Ganymede, Europa, and Callisto. It marked a pivotal moment in space exploration as it was the first spacecraft specifically designed to study the giant planet in detail.

As Galileo approached Jupiter, it deployed a probe that entered the planet's atmosphere, providing crucial data on its composition, temperature, and weather patterns. Over the next several years, Galileo transmitted a wealth of information back to Earth. Its findings included the discovery of a thin atmosphere on Europa and evidence suggesting that an ocean of liquid water might exist beneath its icy surface. These discoveries sparked interest in the potential for extraterrestrial life within our solar system and spurred further exploration of Europa.

The mission faced various challenges, including technical malfunctions and limited communication capabilities. However, its ability to operate in the harsh environment of a gas giant proved groundbreaking. Galileo continued to send data until its mission officially concluded in 2003, after being deliberately directed to plunge into Jupiter’s atmosphere, ensuring that it wouldn't contaminate any of its moons, which are of interest for potential life forms. Galileo's legacy lives on in the advances that it contributed to our understanding of planetary science and astrobiology.