50 Years Ago, NASA Sent an Ambitious Mission to Saturn — and To Interstellar Horizons

Before the early 1970s, NASA’s planetary science missions stuck close to the metaphorical coastline, sending robotic spacecraft to the Moon, Mars, Venus, and Mercury. It would be the twin missions, Pioneer 10 and 11, that were the space agency’s first voyage to set sail to the outer Solar System, exploring deep space beyond the orbit of Mars.