Pioneer 11
- id: PRB-004
- launch_year: 1973
- launch_date: 1973-04-05
- operated_by: NASA
- visited: Jupiter, Saturn
- carried: Geiger Tube Telescope
- people: Carl Sagan, James Van Allen
- status: completed
- confidence: believed-correct
- sources: NASA NSSDCA Master Catalog, JPL missions
Pioneer 11 launched on 5 April 1973 as the twin of Pioneer 10. It flew past Jupiter in December 1974, using the giant planet's gravity to bend its path across the solar system, and in September 1979 became the first spacecraft to fly past Saturn — scouting the route the Voyagers would follow.
Like its twin it carries the Pioneer plaque and James Van Allen's Geiger Tube Telescope. Contact with Pioneer 11 was lost in 1995.