Mariner Missions to Mars

Mariner 3 and 4 were identical spacecraft designed to carry out the first flybys of Mars. Mariner 3 was launched on Nov. 5, 1964, but the shroud encasing the spacecraft atop its rocket failed to open properly, and Mariner 3 did not get to Mars. Three weeks later, on Nov. 28, 1964, Mariner 4 was launched successfully on an eight-month voyage to the Red Planet.

The spacecraft flew past Mars on July 14, 1965, collecting the first close-up photographs of another planet. The pictures, played back from a small tape recorder over a long period, showed lunar-type impact craters (just beginning to be photographed at close range from the Moon), some of them touched with frost in the chilly Martian evening. The Mariner 4 spacecraft was not expected to survive much longer than the eight months to its Mars flyby encounter, but actually lasted about three years in solar orbit, continuing long-term studies of the solar wind environment and making coordinated measurements with Mariner 5, a sister ship launched to Venus in 1967.

Mariner 3 

Mariner 4

Mariner 6 and 7 were the second pair of Mars missions in NASA's Mariner series of solar system exploration in the 1960s and early 1970s. As with the other Mariners, each launched on an Atlas rocket with either an Agena or Centaur upper-stage booster and weighed less than half a ton (without onboard rocket propellant).

In 1969, Mariner 6 and Mariner 7 completed the first dual mission to Mars, flying by over the equator and south polar regions and analyzing the Martian atmosphere and surface with remote sensors, as well as recording and relaying hundreds of pictures. By chance, both flew over cratered regions and missed both the giant northern volcanoes and the equatorial grand canyon that was discovered later. Their approach pictures did, however, show that the dark features on the surface long seen from Earth were not canals, as once interpreted in the 1800s.

Mariner 6

Mariner 7

Mariner 8 and 9 were the third and final pair of Mars missions in NASA's Mariner series of the 1960s and early 1970s. Both were designed to be the first Mars orbiters, marking a transition in our exploration of the Red Planet from flying by the planet to spending time in orbit around it.

Unfortunately, Mariner 8 failed during launch on May 8, 1971. Mariner 9 was launched successfully on May 30, 1971, and became the first artificial satellite of Mars when it arrived and went into orbit, where it functioned in Martian orbit for nearly a year. Mariner 9 completed its final transmission Oct. 27, 1972.

Upon arrival, Mariner 9 observed that a great dust storm was obscuring the whole globe of the planet. Ground controllers sent commands to the spacecraft to wait until the storm had abated, the dust had settled, and the surface was clearly visible before compiling its global mosaic of high-quality images of the Martian surface. The storm persisted for a month, but after the dust cleared, Mariner 9 proceeded to reveal a very different planet than expected -- one that boasted gigantic volcanoes and a grand canyon stretching 3,000 miles (4,800 kilometers) across its surface. More surprisingly, the relics of ancient riverbeds were carved in the landscape of this seemingly dry and dusty planet. Mariner 9 exceeded all primary photographic requirements by photo-mapping 100% of the planet's surface. The spacecraft also provided the first close-up pictures of the two small, irregular Martian moons: Phobos and Deimos.

Mariner 8

Mariner 9