A satellite image of a swirling hurricane Men with gas masks and protective suits on The planetary rover Sojourner A large group of refugees huddled together

EXPLORATION

Mars

Archaeology






Beginning in the 1960s the United States and the Soviet Union targeted Mars as a focus of their respective space programs. U.S. Mariner and Viking series spacecraft first flew by the planet, then orbited it and eventually placed lander modules on the surface. Two Soviet probes reached the surface. The Soviet’s Mars 3 in 1971 became the first capsule containing instruments to soft-land on the planet—the gentle touchdown allowed the craft to send signals back to Earth.

The U.S. Viking missions focused on looking for extraterrestrial life. Although landers from Vikings 1 and 2 in 1976 found no convincing evidence, they did collect detailed information about the planet’s geology and weather.

Vivid pictures of the surface came from the U.S. spacecraft Mars Pathfinder, which arrived at the planet on July 4, 1997. The lander—along with a six-wheeled robotic rover named Sojourner—sent back more than 17,000 images. In all, the mission returned some 2.6 billion bits of data, including chemical analyses of rocks and information about the Martian climate.

By the time Pathfinder and Sojourner fell silent more than seven months later—outlasting all expectations—U.S. and European scientists already had begun laying plans for future missions to the red planet. But such efforts are always risky. Two U.S. spacecraft—the Mars Climate Orbiter and the Mars Polar Lander—failed in 1999, with a combined loss of more than U.S. $285 million.

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image: Surface of Mars
VIDEO:

NASA officials discuss the inevitable failures often encountered in reaching for the stars.


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VIDEO:

The dune-buggy Sojourner scampers over the surface of Mars during the 1997 U.S. Pathfinder mission.


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FAST FACT:

Mars has two moons. Phobos and Deimos were discovered in 1877, but little was known about them until the unmanned U.S. Viking spacecraft flew within 62 miles (100 kilometers) of them a century later.


THE VISIONARY:

The 1997 U.S. Mars Pathfinder mission’s landing craft was renamed from Pathfinder to Carl Sagan Memorial Station to honor the famed astronomer and space visionary who died in 1996 at 62.

Often cited for his role in popularizing science and space exploration, Sagan was a serious researcher whose curiosity about the possibility of intelligent life elsewhere in the universe still lends credibility to the search for it.

Sagan helped NASA launch the world’s first series of interplanetary probes. When they turned up little evidence of life in such inhospitable places as Venus, Mars, Jupiter, Saturn, Uranus, and Neptune, Sagan increasingly set his sights on the stars. But he never ruled out Earth’s red desert neighbor as a possibility altogether.

Scientists involved in the future missions to Mars and Jupiter’s large moon Europa, planned for the first decade of the new millennium, will all remember the brilliant scientist who refused to believe that Earth is the only theater of life. Many proudly proclaim themselves his proteges.

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