A program of unmanned space missions 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.
... station (for the Jubilee Line)
Holborn tube station (for the Aldwych branch of the Piccadilly Line)
These stations once served by the Metropolitan Line, District ...