Galileo
- id: PRB-010
- launch_year: 1989
- launch_date: 1989-10-18
- operated_by: NASA, Jet Propulsion Laboratory
- visited: Jupiter
- status: completed
- confidence: believed-correct
- sources: NASA NSSDCA Master Catalog, JPL missions
Galileo launched on 18 October 1989 aboard Space Shuttle Atlantis and became the first spacecraft to orbit Jupiter, arriving on 7 December 1995 after releasing a probe that plunged into the giant planet's atmosphere and reported back as it fell. The mission was run by JPL for NASA.
Galileo overcame a high-gain antenna that never fully opened, returning years of science through its small backup antenna. En route in 1994 it had the only direct view of the fragments of comet Shoemaker–Levy 9 — co-discovered by Eugene Shoemaker — striking Jupiter's far side. In orbit, its observations of the moon Europa produced strong evidence for a saltwater ocean beneath the ice, a result that reshaped the search for habitable worlds.
To protect that possible ocean from contamination, the spacecraft was deliberately flown into Jupiter's atmosphere on 21 September 2003.