The American Pioneer program of unmanned space missions was designed for planetary exploration. There were a number of such missions in the program, but the most notable were Pioneer 10 and Pioneer 11, which explored the outer planets and left the solar system. Both carry a golden plaque (see Pioneer plaque), depicting a man and a woman and information about the origin and the creators of the probes, should any extraterrestrials find them someday.

• Pioneer 0 - Lunar orbiter, destroyed in launcher failure (Able 1)
• Pioneer 1 - Lunar orbiter, missed Moon due to launcher failure (Able 2)
• Pioneer 2 - Lunar orbiter, destroyed in launcher failure (Able 3)
• Pioneer 3 - Lunar flyby, missed Moon due to launcher failure
• Pioneer 4 - Lunar flyby, achieved Earth escape velocity
• Pioneer X - Lunar probe, lost in launcher failure
• Pioneer Y - Lunar probe, failed to achieve lunar obit
• Pioneer Z - Lunar probe, lost in upper stage failure
• Pioneer 5 - interplanetary space between Earth and Venus
• Pioneer 6, 7, 8 and 9 - interplanetary space "weather network"
• Pioneer A - interplanetary space "weather network"
• Pioneer B - interplanetary space "weather network"
• Pioneer C - interplanetary space "weather network"
• Pioneer D - interplanetary space "weather network"
• Pioneer E - interplanetary space "weather network", lost in launcher failure
• Pioneer 10 - Jupiter, interstellar space
• Pioneer 11 - Jupiter, Saturn, interstellar space
• Pioneer H - identical to Pioneers 10 and 11 (F & G)
• Pioneer Venus 1 - the Pioneer Venus Orbiter of the Pioneer Venus project (Pioneer 12)
• Pioneer Venus 2 - the Pioneer Venus Multiprobe of the Pioneer Venus project (Pioneer 13)
• Pioneer Venus Probe 1 - part of the Pioneer Venus Multiprobe
• Pioneer Venus Probe 2 - part of the Pioneer Venus Multiprobe
• Pioneer Venus Probe 3 - part of the Pioneer Venus Multiprobe
• Pioneer Venus Probe 4 - part of the Pioneer Venus Multiprobe

• Pioneer 1P

See also: Timeline of Planetary Exploration, Able space probes

External links:

• Pioneer Program home page
• Mark Wolverton's The Depths of Space online