, under construction in 1971. Pioneer 10 and 11
are the most famous probes in the Pioneer program. They were the first probes to visit the outer planets
, and the first to go beyond the orbit of Pluto
The Pioneer program is the name of a few unmanned space missions done by NASA between 1958 and 1978. Problably the best-known of these probes were Pioneer 10 and 11, launched in 1972 and 1973 respectively. Both carried a plaque as shown.