Mariner 9, the first spacecraft to orbit a planet other than Earth, travelled to Mars and returned images of the surface, including this one of a Martian shield volcano. The craft’s wide-angle and telephoto lenses captured the summit crater and grooves of the volcano. Experts think the grooves likely resulted from subsurface magma flows, according to NASA.
Mariner 9 launched aboard an Atlas-Centaur SLV-3C booster (AC-23) on May 30, 1971 and arrived at Mars on Nov. 14, 1971. The craft continued atmospheric studies of the Red Planet started by Mariners 6 and 7, and mapped more than 70 percent of the Martian surface.
Originally, Mariner 9 was part of a two-spacecraft mission known as Mariner Mars 71, but Mariner 8 failed to launch properly, so Mariner 9 operated with a set of combined mission objectives. [Photos: Mars Volcano Views Revealed by Spacecraft]
Plans to use Mariner 9 to map the surface of the Red Planet were delayed by a massive dust storm that began on Sept. 22, 1971. By the time Mariner 9 arrived in November, only the summits of Olympus Mons and the three Tharsis volcanoes could be seen on Mars’ surface. The storm became one of the largest global storms recorded on the Red Planet.
The storm slowed later in the month and subsided in December, and the mapping campaign began. Mariner 9 returned 54 billion bits (6.75 gigabytes) of scientific data, including more than 7,300 images of the Red Planet.
The Mariner 9 mission was terminated on Oct. 27, 1972, but the spacecraft was set into a long-lasting orbit that will eventually send the it crashing through the Martian atmosphere.