The Pioneer Probes are a pair of spacecraft, Pioneer 10 and Pioneer 11, launched by NASA in the early 1970s. Their primary mission was to explore the outer planets, with Pioneer 10 becoming the first spacecraft to travel through the asteroid belt and make a flyby of Jupiter in 1973. Pioneer 11 followed, making its historic flyby of Saturn in 1979.
Both probes provided valuable data about the planets they encountered, including information about their atmospheres, magnetic fields, and radiation belts. After completing their primary missions, the Pioneer Probes continued to send data back to Earth until their signals faded, contributing to our understanding of the solar