Mariner probes were designed to explore the planets. The most famous were:
- Mariner 2 to Venus in 1963;
- Mariner 4 to Mars in 1967;
- Mariner 5 to Venus in 1967 to analyze the atmosphere;
- Mariner 6 and 7 Mars to analyze the atmosphere in 1969;
- Mariner 9 in orbit around Mars and sent the first detailed images of Phobos and Deimos in 1972;
- Mariner 10 to Mercury and Venus in 1974 and 1975, sending a harvest of images and valuable data.